curriculum training

Curriculum Training

Diesel Injection and Engine ManagementSystems

Common Rail Systems

Technical Service TrainingCG 8180/S en 12/2005

TC3043048H

To the best of our knowledge, the illustrations, technical information, data and descriptions in this issue were correct at the time

of going to print. The right to change prices, specifications, equipment and maintenance instructions at any time without notice

is reserved as part of FORD policy of continuous development and improvement for the benefit of our customers.

No part of this publication may be reproduced, stored in a data processing system or transmitted in any form, electronic,

mechanical, photocopy, recording, translation or by any other means without prior permission of Ford-Werke GmbH. No liability

can be accepted for any inaccuracies in this publication, although every possible care has been taken to make it as complete and

accurate as possible.

Copyright ©2006

Ford-Werke GmbH

Service training programs D-F/GT1 (GB)

More stringent exhaust and noise emission standards and requirements regarding lower fuel consumption continue

to place new demands on the fuel injection and engine management system of diesel engines.

In order to satisfy these requirements, the injection system must inject the fuel at high pressure into the combustion

chamber to provide good mixture preparation and, at the same time, meter the injected fuel quantity with the highest

possible accuracy. The Common Rail System offers good potential for development, which is of particular

significance both now and in the future. By separating the pressure generation process from the injection process,

the optimum injection pressure is always available for the injection process, regardless of engine speed.

The newly developed engine management system ensures that the fuel injection timing and injected fuel quantity

are calculated exactly, and that the fuel is delivered to the engine cylinders by the piezo-controlled fuel injectors.

The following common rail systems are currently used in Ford vehicles:

– Delphi common rail system,

– Bosch common rail system,

– Siemens common rail system,

– Denso common rail system.

Another big step towards achieving cleanliness in diesel engines is the newly developed diesel particulate filter

system. This system helps reduce micro-fine diesel particulates by up to 99%.

Completion of the eLearning program "Diesel Fuel Injection and Engine Management Systems" is a prerequisite

for the study of this Student Information.

This Student Information is divided into lessons. The objectives that should be met by working through the lesson

are set out at the beginning of each lesson. At the end of each lesson there is a set of test questions which are

designed to monitor the student's progress. The solutions to these test questions can be found at the end of the

Student Information.

Please remember that our training literature has been prepared for FORD TRAINING PURPOSES only. Repairs

and adjustments MUST always be carried out according to the instructions and specifications in the workshop

literature. Please make full use of the training offered by Ford Technical Training Courses to gain extensive

knowledge of both theory and practice.

1Service Training (G544949)

Preface

Preface..............................................................................................................................

Lesson 1 – General Information

13Objectives....................................................................................................................................................

14Overview of the Systems................................................................................................................................................

17Introduction.....................................................................................................................................................................

18Injection characteristics...................................................................................................................................................

21Emission Standard IV with or without diesel particulate filter.......................................................................................

21Cleanliness when working on the common rail system..................................................................................................

22EOBD (European On-board Diagnostic).................................................................................................

22General............................................................................................................................................................................

23Fault logging and storing................................................................................................................................................

25Engine Emission Control...........................................................................................................................

25Pollutant emissions reduction.........................................................................................................................................

27Test questions..............................................................................................................................................

Lesson 2 – Delphi-Common Rail System

29Objectives....................................................................................................................................................

30Overview of the two-module system – system with PCM and separate IDM................................................................

32Overview of the single-module system – system with one PCM (IDM integrated in the PCM)....................................

33Characteristics.................................................................................................................................................................

33Special features...............................................................................................................................................................

34Service instructions.........................................................................................................................................................

34EEC V powertrain control module PCM (two-module system).....................................................................................

36IDM (two-module system)..............................................................................................................................................

Service Training2

Table of Contents

38Delphi PCM (single-module system)..............................................................................................................................

39Glow plug control...........................................................................................................................................................

41Sensors.........................................................................................................................................................

41CKP sensor......................................................................................................................................................................

42CMP sensor.....................................................................................................................................................................

43MAP/IAT and T-MAP sensor..........................................................................................................................................

44CHT sensor.....................................................................................................................................................................

46MAF sensor.....................................................................................................................................................................

46VSS.................................................................................................................................................................................

47APP sensor......................................................................................................................................................................

48KS....................................................................................................................................................................................

48Fuel temperature sensor..................................................................................................................................................

49Fuel pressure sensor........................................................................................................................................................

49Fuel pressure outside the specified range........................................................................................................................

50Position sensor in vacuum-operated EGR valve.............................................................................................................

51Position sensor in electric EGR valve.............................................................................................................................

52Switch...........................................................................................................................................................

52Stoplamp switch/BPP switch..........................................................................................................................................

52CPP switch......................................................................................................................................................................

53Actuators.....................................................................................................................................................

53Fuel metering valve.........................................................................................................................................................

54Fuel injector solenoid valve............................................................................................................................................

56EGR solenoid valve and boost pressure control solenoid valve.....................................................................................

56Intake manifold flap and intake manifold flap solenoid valve........................................................................................

57Electric EGR valve (certain versions only).....................................................................................................................

59Electrical turbocharger guide vane adjustment actuator.................................................................................................

3Service Training

Table of Contents

62Strategies.....................................................................................................................................................

62Ignition ON strategy........................................................................................................................................................

62Engine start strategy........................................................................................................................................................

65Idle strategy.....................................................................................................................................................................

65Idle speed control............................................................................................................................................................

66Fuel metering calculation................................................................................................................................................

69Smooth-running control (cylinder balancing).................................................................................................................

69External fuel quantity intervention.................................................................................................................................

69Controlling fuel injection................................................................................................................................................

71Controlling the fuel pressure...........................................................................................................................................

73EGR system.....................................................................................................................................................................

76Boost pressure control.....................................................................................................................................................

78PCM fault strategy..........................................................................................................................................................

78Monitoring the system....................................................................................................................................................

80Coated diesel particulate filter..................................................................................................................

80Overview – diesel particulate filter.................................................................................................................................

81Passive regeneration........................................................................................................................................................

81Active regeneration.........................................................................................................................................................

82Notes on the oil change interval......................................................................................................................................

83Emission control components.........................................................................................................................................


84Exhaust gas temperature sensors.....................................................................................................................................

84Diesel particulate filter differential pressure sensor........................................................................................................

86MAP sensor.....................................................................................................................................................................

86Intake manifold flap and intake manifold flap solenoid valve........................................................................................

87Intake manifold flap position sensor...............................................................................................................................

Service Training4

Table of Contents

88Fuel System.................................................................................................................................................

88Overview.........................................................................................................................................................................

89General............................................................................................................................................................................

90Fuel filter.........................................................................................................................................................................

91Overview – high-pressure system...................................................................................................................................

92High pressure pump........................................................................................................................................................

96Fuel rail (common rail)...................................................................................................................................................

97Excess pressure safety valve...........................................................................................................................................

98High-pressure fuel lines and leak-off pipes....................................................................................................................

98Fuel injectors...................................................................................................................................................................

103Test questions..............................................................................................................................................

Lesson 3 – Bosch-Common Rail System

105Objectives....................................................................................................................................................

106Overview.........................................................................................................................................................................



108PCM................................................................................................................................................................................


112Sensors.........................................................................................................................................................

112CKP sensor......................................................................................................................................................................

112CMP sensor.....................................................................................................................................................................

113MAP sensor.....................................................................................................................................................................

114BARO sensor...................................................................................................................................................................

114ECT sensor......................................................................................................................................................................

116Combined IAT sensor and MAF sensor..........................................................................................................................

5Service Training

Table of Contents

117Vehicle speed signal........................................................................................................................................................

117APP.................................................................................................................................................................................

118Fuel temperature sensor..................................................................................................................................................


120Switch...........................................................................................................................................................

120Oil pressure switch..........................................................................................................................................................

120Stoplamp switch/BPP switch..........................................................................................................................................

120CPP switch......................................................................................................................................................................

121Actuators.....................................................................................................................................................

121Fuel metering valve (CP3.2)...........................................................................................................................................

122Fuel metering valve (CP1H)...........................................................................................................................................


125Boost pressure control solenoid valve.............................................................................................................................

126EGR valve.......................................................................................................................................................................

127Intake manifold flap servo motor (vehicles with diesel particulate filter)......................................................................

130Strategies.....................................................................................................................................................

130Regeneration process......................................................................................................................................................

132EGR system.....................................................................................................................................................................



136Other strategies...............................................................................................................................................................

137Diesel particulate filter with fuel additive system....................................................................................

137Component overview......................................................................................................................................................

138Diesel particulate filter....................................................................................................................................................

140Intercooler bypass...........................................................................................................................................................

142Fuel additive system – general........................................................................................................................................

Service Training6

Table of Contents

143System components – fuel additive system....................................................................................................................

145Component overview – system control...........................................................................................................................


146Control modules..............................................................................................................................................................

147Fuel additive pump unit..................................................................................................................................................

148Tank flap switch..............................................................................................................................................................

149IAT sensor.......................................................................................................................................................................

150Exhaust gas temperature sensor......................................................................................................................................

150Diesel particulate filter differential pressure sensor........................................................................................................

152Intake manifold flap servo motor....................................................................................................................................

153Intercooler bypass flap servo motor................................................................................................................................

155Fuel System.................................................................................................................................................

155Overview.........................................................................................................................................................................

156General............................................................................................................................................................................

157Fuel filter.........................................................................................................................................................................




166High pressure fuel lines...................................................................................................................................................

166Fuel injectors...................................................................................................................................................................

171Test questions..............................................................................................................................................

Lesson 4 – Siemens-Common Rail System

173Objectives....................................................................................................................................................

174Overview.........................................................................................................................................................................


7Service Training

Table of Contents

177Special features...............................................................................................................................................................


178PCM................................................................................................................................................................................


181Sensors.........................................................................................................................................................

181MAP sensor.....................................................................................................................................................................

182IAT sensor.......................................................................................................................................................................

183BARO sensor...................................................................................................................................................................

184Turbocharger position sensor (certain versions only).....................................................................................................

184ECT sensor......................................................................................................................................................................

185CHT sensor (1.8L Duratorq-TDCi (Kent) diesel only)...................................................................................................

186Combined IAT sensor and MAF sensor..........................................................................................................................

187Vehicle speed signal........................................................................................................................................................

188APP sensor......................................................................................................................................................................

189Vacuum-operated intake manifold flap position sensor (certain vehicles with emission standard IV)..........................


191Other sensors...................................................................................................................................................................

192Switch...........................................................................................................................................................

192Information......................................................................................................................................................................

193Actuators.....................................................................................................................................................


195Fuel pressure control valve.............................................................................................................................................

199Piezo-electric control of fuel injectors............................................................................................................................

201Boost pressure control valve (variable geometry turbocharger, vacuum-controlled).....................................................


203Intake manifold flap and intake manifold flap solenoid valve (vacuum-operated systems)...........................................

Service Training8

Table of Contents

204Intake manifold flap servo motor (1.4L Duratorq-TDCi (DV) diesel engine, emission standard IV)............................

205EGR valve solenoid valve (vacuum-controlled systems)................................................................................................

206EGR valve (electrically controlled systems)...................................................................................................................

208Engine warm-up regulation(only 2.0L Duratorq-TDCi (DW) diesel engine).......................................

208Note.................................................................................................................................................................................

208Component locations.......................................................................................................................................................

209Principle of operation......................................................................................................................................................



214Other strategies...............................................................................................................................................................

215Diesel particulate filter with fuel additive system....................................................................................

215Note.................................................................................................................................................................................

215Component overview......................................................................................................................................................

216Diesel particulate filter....................................................................................................................................................

217Intercooler bypass...........................................................................................................................................................

219Component overview – system control...........................................................................................................................


220Exhaust gas temperature sensors.....................................................................................................................................

222Intake manifold flap and intercooler bypass flap solenoid valves..................................................................................

224Coated diesel particulate filter..................................................................................................................

224Overview – diesel particulate filter.................................................................................................................................

225Emission control components.........................................................................................................................................


226Intake manifold flap, intake manifold flap position sensor and intake manifold flap solenoid valve............................

227Siemens system............................................................................................................................................

227Overview.........................................................................................................................................................................

9Service Training

Table of Contents

228General............................................................................................................................................................................

229Fuel filter.........................................................................................................................................................................

230Manual pump..................................................................................................................................................................

231High-pressure system – general......................................................................................................................................


236Fuel rail (common rail) and high pressure fuel lines......................................................................................................

238Fuel injectors...................................................................................................................................................................

243Test questions..............................................................................................................................................

Lesson 5 – Denso-Common Rail System

245Objectives....................................................................................................................................................

246Overview.........................................................................................................................................................................

247Notes on this lesson.........................................................................................................................................................



248PCM................................................................................................................................................................................

250Sensors.........................................................................................................................................................

250MAF sensor.....................................................................................................................................................................

250APP sensor......................................................................................................................................................................

251Oil level/temperature sensor...........................................................................................................................................

254Actuators.....................................................................................................................................................




257Fuel system..................................................................................................................................................

257Overview.........................................................................................................................................................................

Service Training10

Table of Contents

258General............................................................................................................................................................................

258Fuel filter.........................................................................................................................................................................




266Fuel injectors...................................................................................................................................................................

268Test questions..............................................................................................................................................

269Answers to the test questions.........................................................................................

270List of Abbreviations.......................................................................................................

11Service Training

Table of Contents

On completing this lesson, you will be able to:

• explain the advantages of the common rail system.

• state the reasons for the use of pilot injection.

• explain what effect pilot injection has on combustion.

• state the reasons for the use of post-injections.

• explain which types of post-injections are used.

• explain the purpose of the EOBD system.

• name the different monitoring systems of the diesel EOBD system.

• explain the fault detection and storage of emission-relevant faults.

• state the reasons for the use of the diesel particulate filter.


ObjectivesLesson 1 – General Information

Overview of the Systems

Delphi common rail system

E47800

A

B

1

2

3

Two-module systemA

Single-module systemB

IDM (Injector Driver Module)1

EEC V-PCM (Powertrain Control Module)2

Delphi PCM3

(G544950) Service Training14


Bosch common rail system

E51104



Siemens common rail system

E53583



Denso common rail system

E69955

Introduction

Increasingly higher demands are being placed on modern

diesel engines. The focus is not only on exhaust

emissions but also on increasing environmental

awareness and the demand for increasingly better

economy and enhanced driving comfort.

This requires the use of complex injection systems, high

injection pressures and accurate fuel metering by fully

electronically-controlled systems.

The high injection pressures convert the fuel, via the

injector nozzle, into tiny droplets, which, again due to

the high pressure, can then be optimally distributed in

the combustion chamber. This results in fewer unburned



HC (Hydrocarbon)s, less CO (Carbon Monoxide) and

fewer diesel exhaust particulates being produced in the

subsequent combustion stage.

In addition, the optimized mixture formation reduces

fuel consumption.

Diesel knock caused by the combustion process of an

engine with direct injection is significantly reduced by

means of additional pilot injection (pilot injection). NOX

(Oxides Of Nitrogen) emissions can also be reduced by

using this method.

Demands for better driving comfort also influence the

requirements placed on today's diesel engines. In

particular, the importance of noise and exhaust

emissions continues to increase. This leads to increased

demands being placed on the injection system and its

control, e. g.:

• high injection pressures,

• shaping of injection timing characteristics,

• pilot injection,

• injected fuel quantity, start of injection and boost

pressure values adapted to every operating condition,

• load-independent idle speed control,

• closed loop EGR (Exhaust Gas Recirculation),

• low injection timing and injected fuel quantity

tolerances and high degree of precision for the entire

service life,

• options to interact with other systems, such as the

Electronic Stability Program, PATS (Passive

Anti-theft System),

• comprehensive diagnostic facilities,

• substitute strategies in the event of faults.

The common rail injection system has a large range

of features to meet these demands.

In common rail injection systems, pressure generation

is separate from the injection process. The injection

pressure is generated independently of engine speed and

injected fuel quantity.

The common rail injection system consists of a

high-pressure pump and a fuel rail (fuel accumulator).

The fuel in this fuel rail is at a constant pressure and is

available for distribution to the electrically controlled

fuel injectors.

With this type of diesel injection or engine management

system, the driver does not have a direct influence on

the quantity of injected fuel, because, for example, there

is no mechanical connection between the accelerator

pedal and the injection pump. Here, the injected fuel

quantity is determined by various parameters. These

include:

• driver demand (accelerator pedal position),

• operating state,

• engine temperature,

• effects on exhaust emissions,

• prevention of engine and transmission damage,

• faults in the system.

Using these parameters, the injected fuel quantity is

calculated in the PCM and fuel injection timing and

injection pressure can be varied.

The fuel is metered fully electronically via piezo

elements controlled by the PCM which are located

directly in the fuel injectors.

The fully electronic diesel engine management system

features a comprehensive fail-safe concept (integrated

in the PCM software). It detects any deviations and

malfunctions and initiates corresponding actions

depending on the resulting effects (e.g. limiting the

power output by reducing the quantity of fuel).

Injection characteristics

As already mentioned at the beginning of the lesson,

the exhaust emissions and fuel consumption of an

engine are of great significance. These factors can only



be minimized through precise operation of the injection

system and comprehensive engine management

strategies.

Consequently, the following requirements must be met

by the common rail system:

• The injection timing must be exact. Even small

variations have a significant effect on fuel

consumption, exhaust emissions and combustion

noise.

• The fuel injection pressure is independently adapted

to all operating conditions.

• Injection must be terminated reliably. Calculation

of the injected quantity and the injection timing is

precisely adapted to the mechanical components of

the injection system. Uncontrolled fuel dribble (for

example, caused by a defective fuel injector) results

in increased exhaust emissions and increased fuel

consumption.

Simple main injection:

Needle lift of fuel injector nozzle and pressure curve in

the cylinder without pilot injection

E64973

1

2

3

4

5

Combustion pressure in the cylinder1

Needle lift2

TDC (Top Dead Center)3

Needle lift for simple main injection4

Crank angle5

In the case of diesel engines with a distributor-type

fuel injection pump (for example in the Transit 2000.5),

the fuel injection on the pump-side is via simple main

injection.

The fuel is then injected mechanically into the

combustion chamber by the injector nozzles in two

seamlessly integrated stages (two-spring nozzle carrier

principle).

In the pressure curve, the combustion pressure increases

only slightly in the phase before TDC, corresponding

to compression, but increases very sharply at the start

of combustion.

The steep pressure rise intensifies the combustion noise.



Pilot injection

Needle lift of fuel injector nozzle and pressure curve in

the cylinder with pilot injection

E64974

1

2

3

45

6


Needle lift2

TDC3

Needle lift for pilot injection4

Needle lift for main injection5

Crank angle6

In the case of vehicles with common rail injection

systems electrically-controlled pilot injection occurs

after a set time prior to the main injection event.

In the case of pilot injection, a small amount of fuel is

injected into the cylinder prior to the main injection.

Pilot injection results in a gradual increase in the

combustion pressure, leading to an improvement in

combustion quality.

The small, pilot injection fuel quantity is ignited and

heats up the upper part of the cylinder, thereby bringing

it into an optimum temperature range (pre-conditioning

of the combustion chamber).

This means that the main injection mixture ignites more

quickly and the rise in temperature is less abrupt as a

result.

This also results in a less abrupt increase in combustion

pressure, significantly reducing combustion noise.

Advantage:

• Continuous build-up of combustion pressure,

resulting in reduced combustion noise,

• Reduction of nitrogen oxides in the exhaust gas.

Note: As pressure generation and injection in common

rail systems are separate, it is possible to considerably

enhance the range for pilot injection (up to approx. 3000

rpm regardless of engine load). This has led to a decisive

improvement in the running characteristics of the engine.

Post-injection (vehicles with diesel particulatefilter system)

Needle lift of injector nozzle with pre- and post-injection

E51105

12

45 6

3

Needle lift1

Pilot injection2

Crank angle3

Main injection4

Advanced post-injection5

Retarded post-injection6



For vehicles with a diesel particulate filter system two

post-injections are employed during the regeneration

process, in addition to the pre- and main injections,

depending on the requirements.

Advanced post-injection is initiated in certain

load/speed ranges immediately after main injection.

Fuel is then injected during the ongoing combustion.

The main purpose of this advanced post-injection is to

raise the exhaust gas temperature during the regeneration

process of the particulate filter. In addition, some of the

diesel particulates produced during regeneration are

after-burned.

Retarded post-injection only occurs shortly before

BDC (Bottom Dead Center) and also serves to raise the

exhaust gas temperature.

In contrast to the previous injections, during retarded

post-injection the fuel is not burnt, but evaporates due

to the residual heat in the exhaust gas. This exhaust/fuel

mixture is delivered to the exhaust system by the exhaust

stroke.

In the oxidation catalytic converter, the fuel vapor reacts

with the residual oxygen (above a certain temperature)

and burns. This provides sustained heating of the

oxidation catalytic converter, which supports the

regeneration of the particulate filter.

Emission Standard IV with or withoutdiesel particulate filter

At the time of going to press emission standard IV

applies in Europe.

In the diesel sector, emission standard IV is achieved

using two different methods.

One method consists of reducing exhaust emissions by

means of internal engine measures to the extent that

the prescribed limit values are met.

Measures for the reduction of exhaust emissions inside

the engine include, for example:

• further optimized exhaust gas recirculation by means

of an electrically controlled EGR system with intake

air restriction,

• optimization of the combustion chamber design and

the injection characteristics.

In addition to optimization through internal engine

measures, the second method employs a diesel

particulate filter system.

With the use of diesel particulate filters, diesel

particulate emissions are reduced by more than 99%.

This reduction far exceeds the requirements for the

European emission limits of emission standard IV.

It can therefore be assumed that the use of the diesel

particulate filter will be of great importance with regard

to future emission standards, but is not absolutely

necessary for meeting emission standard IV.

Cleanliness when working on thecommon rail system

NOTE: Because the components of the high-pressure

fuel system are high-precision machined parts, it is

essential that scrupulous cleanliness is observed when

carrying out any work on the system.

In this regard, refer to the instructions in the current

Service Literature.



General

E52683

The EOBD system does not use any additional sensors

or actuators to individually measure pollutants in the

exhaust emissions.

The EOBD system is integrated into the software of the

PCM and uses the existing sensors and actuators of the

engine management system.

With the aid of these sensors, actuators and the special

software, systems and components significant for

emissions are continually checked during the journey

and exhaust emissions calculated accordingly.

Components significant for emissions are checked with

the so-called monitoring system.

With the introduction of EOBD for European Ford diesel

engines as of 1 January 2004 this will comprise the

following monitoring systems (monitors):

• monitoring of components significant to emissions

(Comprehensive Component Monitors = CCM),

• monitoring of the EGR system,

• boost pressure monitoring,

• fuel pressure monitoring.

Monitoring system for components significantfor exhaust emissions (CCM)

The monitoring system for components significant for

emissions (CCM) continually checks to see if the sensors

and actuators significant for emissions are operating

within the specified tolerances when the engine is

running.

If a sensor or actuator is outside the tolerance range,

this is recognized by the monitoring system and a DTC

is stored in the data memory.

Monitoring of the EGR system

The operation of the EGR system is monitored to

identify faults that lead to increased exhaust emissions

and may exceed the EOBD threshold values.

This monitoring system was developed so that it can,

among other things, check the flow characteristics of

the EGR system.

Boost pressure monitoring

Boost pressure control operates via the boost pressure

control solenoid valve and the MAP (Manifold Absolute

Pressure) sensor in a closed control loop.

The boost pressure is constantly monitored via the MAP

sensor.

Fuel pressure monitoring

Fuel pressure monitoring operates via the fuel metering

valve and the fuel pressure control valve. Feedback

regarding the current fuel pressure is received via the

fuel pressure sensor.


Lesson 1 – General InformationEOBD

MIL (Malfunction Indicator Lamp)

E48311

The MIL is located in the instrument cluster and shows

an engine icon (international standard).

The MIL warns the driver that the EOBD system has

detected an emissions-related fault in a component or

system.

If an emissions-related fault is detected and if this fault

is confirmed during the third driving cycle, the MIL

is switched on.

After the MIL has been switched on, a fault log is

created in the PCM. The fault logs contain information

regarding the type of fault and the time since the MIL

was activated.

The MIL ensures that a fault is recognized in time. The

defect can be repaired in good time and the emission of

exhaust gas with high levels of pollutants is avoided.

Fault logging and storing

A fault occurring for the first time is labeled in the freeze

frame data as a suspected fault (pending code) and is

stored in the data memory.

If the fault is not confirmed in the next check, it is

erased.

If it is confirmed during the third drive cycle, the

suspected fault is automatically converted into a

confirmed fault (continuous code). The freeze frame

data does not change. It remains the same as when the

fault first occurred.

The MIL only illuminates when the fault has been stored

as a confirmed fault.

If the fault does not recur in the course of three

consecutive drive cycles, the MIL extinguishes in the

fourth drive cycle. However, the fault code remains

stored in the data memory.

Faults which do not reoccur are automatically cleared

from the memory after 40 warm-up cycles.

If a faulty signal is detected during a journey and the

corresponding fault code is stored, all the checks in

which this signal is required as a comparison variable

are interrupted. This prevents follow-up faults from

being stored.

Diagnostic trouble codes can be read or cleared with

the WDS ( Worldwide Diagnostic System) Ford

diagnostic tester.

Drive cycle

A drive cycle commences when the engine starts (engine

cold or hot) and ends when the engine is stopped.

Depending on the complexity of the fault, the

monitoring period may vary:

• For simple electrical faults, a monitoring period of

less than five minutes is sufficient.

• For the purpose of monitoring a system (for example

the EGR system) where different operating

conditions etc. are required to complete the test, the

test can take up to about 20 minutes.


EOBDLesson 1 – General Information

Warm-up cycle

A warm-up cycle starts when the engine is started, at

which point the coolant temperature must be at least 22

°C, and ends as soon as the coolant temperature exceeds

70 °C.


Lesson 1 – General InformationEOBD

Pollutant emissions reduction

Maximum exhaust emission levels for passenger vehicles in grams per kilometer (g/km)

Particulate

matter (PM) (g/

km)

HC + NOXNOX (g/km)HC (g/km)CO (g/km)

0.050.560.50-0.64Emission

Standard III

0.0250.300.25-0.50Emission

Standard IV

0.18-1.200.403.20EOBD limits

In order to meet the increasingly stringent emission

standards, exhaust gas after treatment will increase in

significance even for diesel engines, despite the progress

made with regard to engine modifications.

By constantly improving the injection systems (direct

injection in conjunction with constantly increasing

injection pressures) and their electronic control, the

performance, economy and comfort of the diesel engine

has steadily been increased.

Also of significance is the reduction of exhaust gas

emissions, the maximum levels of which have to be

continuously improved due to legal requirements.

The measures inside the engine (high injection

pressures, nozzle design, timed introduction of fuel and

combustion chamber shape) have lowered the CO, HC

and diesel particulate emissions to a large extent.

The NOX emissions produced by excess air in diesel

combustion are effectively reduced by exhaust gas

recirculation systems which are constantly being

improved.

The oxidation catalytic converter, in use for some

years now, represents the first stage of exhaust gas

aftertreatment. It further reduces HC and CO

emissions.

Diesel particulate matter

As previously mentioned, a considerable reduction in

diesel particulate matter has already been achieved by

modifications to the engine.

Since the introduction by the EU Commission in 1989

of the first emission standard for diesel passenger

vehicles, the limit for diesel particulates has been

reduced from 1.1 g/km by a factor of 22 to only 0.05

g/km today (Emission Standard III).

With regard to Emission Standard IV (0.025 g/km) it is

becoming clear, however, that the means by which diesel

particulate emissions can be reduced through engine

modifications have been virtually exhausted.

A further incentive for achieving a reduction is

increasing environmental awareness and the fact that

the residual diesel particulate matter has a harmful effect

on the human body.

Diesel particulates are composed mainly of a chain of

carbon particles (soot) with a very large specific surface

area.

The noxious effect of diesel particulate matter is a result

of adsorption of unburned or partially burned HC. In

addition, fuel and lubricant oil aerosols (solid or liquid


Engine Emission ControlLesson 1 – General Information

substances finely distributed in gases) and sulphates

(depending on the sulphur content of the fuel) bind with

the soot.

Diesel particulate filter

Starting from model year 2004.75, a diesel particulate

filter system for exhaust gas after-treatment will be used

for the first time on Ford vehicles with diesel engines

(initially only as an option on the Focus C-MAX).

By using appropriate filter materials it is possible to

retain in the filter more than 99 % of the diesel

particulates that are still emitted today.

With this method almost all of the particulates can be

retained, however the complete removal of diesel

particulates using conventional catalytic methods is not

possible. The diesel particulates are deposited in the

diesel particulate filter.

As the collection capacity of the diesel particulate filter

is only limited, it has to be regenerated at regular

intervals.

Intervention in engine management system

During regeneration, comprehensive closed-loop control

circuits are activated in the engine management system

depending on different temperatures and pressures.

To achieve the necessary temperature for regeneration,

different operations are performed (for example

throttling the intake air, post-injections).

These operations serve to raise the exhaust gas

temperature while keeping the added fuel consumption

as low as possible.

Fuel additive

With some diesel particulate filter systems the

temperature for combusting the diesel particulates is

lowered by approx. 100 °C by adding a fuel additive.

Coated diesel particulate filter

The filter material of this diesel particulate filter is

coated with a precious metal. This precious metal

coating helps to convert the diesel particulates

catalytically at a temperature of 300 ... 450 °C.

However, it is often not possible to attain temperatures

this high in urban traffic. In this case, the diesel

particulates are deposited in the diesel particulate filter.

To burn them off, regeneration must be initiated at

regular intervals by an intervention into the engine

regulation.


Lesson 1 – General InformationEngine Emission Control

Tick the correct answer or fill in the gaps.

1. What is the advantage of the common rail system?

a. The high injection pressures reduce combustion temperatures; exhaust gas recirculation is not required.

b. Pressure generation and injection are separated.

c. The injection pressure is generated as a function of engine speed.

d. Combustion noise is substantially reduced as a result of indirect injection.

2. What is the effect of pilot injection?

a. Pilot injection results in an abrupt build-up of combustion pressure and therefore reduced combustion noise.

b. Pilot injection results in an abrupt build-up of combustion pressure and therefore increased combustion

noise.

c. Pilot injection results in a gradual increase in the combustion pressure.

d. Pilot injection only results in a reduction of fuel consumption.

3. Where are post-injections utilized?

a. in vehicles with an electric EGR system

b. in vehicles with an NOX catalytic converter

c. in vehicles with no diesel particulate filter system

d. in vehicles with a diesel particulate filter system

4. When does the MIL indicate an emissions-related fault?

a. Immediately after the emissions-related fault has occurred

b. If an emissions-related fault has been confirmed after the second consecutive drive cycle

c. If an emissions-related fault has been confirmed after the third consecutive drive cycle

d. If the emissions-related fault has been confirmed after the second warm-up cycle


Test questionsLesson 1 – General Information


• name all the engine management components.

• explain the difference between the two-module system and the single-module system.

• explain how the glow plug control system works and be able to identify fault symptoms.

• explain the task and function of the individual engine management components.

• describe some fault symptoms when individual components malfunction.

• explain various strategies of the engine management system.

• draw conclusions about possible faults in the engine management system.

• name the components of the diesel particulate filter system and be familiar with their function.

• explain how the diesel particulate filter system works.

• name the components of the fuel and injection system and be familiar with their purpose and function.

• interpret the symptoms of defects on the fuel system and draw conclusions.

• explain what must be done after exchanging an fuel injector.


ObjectivesLesson 2 – Delphi-Common RailSystem

Overview of the two-module system – system with PCM and separate IDM

E70240

1

2

3

4

5

6

7

8

9

10

11

12

14

13

15

16 17

18

19

20

21

22

23

24

25

26

27


Lesson 2 – Delphi-Common RailSystem

CHT (Cylinder Head Temperature) sensor1

Manifold absolute pressure sensor with integrated

T-MAP (Temperature And Manifold Absolute

Pressure) sensor

2

MAF (Mass Air Flow) sensor3

APP (Accelerator Pedal Position) sensor4

BPP (Brake Pedal Position) switch5

CPP (Clutch Pedal Position) switch6

Position sensor in EGR valve7

CKP (Crankshaft Position) sensor8

CMP (Camshaft Position) sensor9

KS (Knock Sensor)10

High-pressure sensor11

IDM (BARO (Barometric Pressure) sensor

integrated in the control unit)12

High pressure pump13

Ignition lock14

PCM15

CAN (Controller Area Network)16

DLC (Data Link Connector)17

EGR valve18

Boost pressure control solenoid valve19

Intake manifold flap solenoid valve (85-kW

Focus only)20

Glow plug warning indicator/fault lamp21

Sheathed-type glow plugs22

Cooling fan control23

Electric auxiliary heater (not for Scandinavian

countries)24

A/C cut-off relay (WAC)25

A/C compressor clutch26

Fuel injector27



Overview of the single-module system – system with one PCM (IDM integrated inthe PCM)

E70241

16

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

17

1819

20

21

22

23

24

25

26

27

28

29



CHT sensor1

Manifold absolute pressure sensor with integrated

T-MAP sensor2

MAF sensor3

APP sensor4

BPP switch5

CPP switch6


CKP sensor8

CMP sensor9

KS10

Fuel pressure sensor11

Electric EGR valve (some versions with emission

standard IV)12

Ignition lock13


PCM (BARO sensor integrated in the control

unit)15

CAN16

DLC17

Electrical turbocharger guide vane adjustment

actuator (emissions standard level IV only)18

EGR valve (not all versions)19


Intake manifold flap solenoid valve (not all

versions)21

Glow plug warning indicator/fault lamp22

MIL(vehicles with EOBD)23


Cooling fan control25

Electric auxiliary heater (not for Scandinavian

countries)26



Fuel injector29

Characteristics

The following components originate from the Delphi

company:

• High pressure pump (with fuel metering valve and

fuel temperature sensor),

• Fuel rail (with fuel pressure sensor and pressure

limiting valve),

• Fuel injectors.

The high pressure pump generates the fuel pressure

required and conveys it into the fuel rail. Fuel metering

is performed by electrically actuating the fuel injectors

by the PCM or by the IDM.

Special features

Solenoid valve-controlled fuel injectors are used in the

Delphi common rail system.

In older systems a PCM and an IDM are used for engine

management.

In more recent systems, the entire engine management

is carried out by a PCM.



Service instructions

Fuel injectors

A 16-digit identification number is engraved on every

fuel injector. After replacing one or more fuel

injector(s), the identification number of the

corresponding fuel injector must be entered with the aid

of WDS.

After a new software version has been loaded, it is also

necessary to enter the identification numbers of all fuel

injectors with the aid of WDS.

Exact instructions on the input of identification numbers

can be found in the current Service Literature.

Vehicles with coated diesel particulate filter

After replacing the PCM following a PCM crash

(communication with the PCM can no longer be

established using WDS) it may also be necessary to

replace the diesel particulate filter. In this regard, always

refer to the instructions in the current Service Literature.

After replacing the diesel particulate filter, using WDS

it is necessary to perform a supervisor parameter reset

as well as a reset of the parameters of the diesel

particulate filter differential pressure sensor in PCM. In

this regard, always refer to the instructions in the current

Service Literature.

After replacing the diesel particulate filter differential

pressure sensor it is necessary to reset the parameters

for the diesel particulate filter differential pressure

sensor. In this regard, always refer to the instructions

in the current Service Literature.

EEC V powertrain control module PCM(two-module system)

E47821

NOTE: If the PCM has been programmed with the latest

software version using WDS, ensure that the IDM is

programmed with the latest software version as well. If

this was not done automatically at the re-programming

stage, then it must be done manually immediately.

Otherwise increased combustion noise, increased fuel

consumption and black smoke emissions may result.

In the common rail injection system (two-module

system) an EEC V-PCM very similar to that in the VP

30/VP 44 injection system is used.

The EEC V-PCM calculates the overall injected fuel

quantity and the injection timing and then sends the

calculated data to the IDM, which actuates the solenoid

valve-controlled fuel injectors accordingly.

The control program (the software) is stored in a

memory. The execution of the program is carried out

by a microprocessor.

In addition to the actuators, there are also sensors which

form the interface between the vehicle and the PCM as

a processing unit.

The sensors, actuators and the power supply are

connected to the PCM via a multi-pin connector.

Input signals from the sensors can have different forms.

Analog input signals



Analog input signals can have any voltage value within

a given range. Examples of analog input signals include:

• IAT (Intake Air Temperature),

• MAP,

• ECT (Engine Coolant Temperature).

As the microprocessor of the PCM can only process

digital signals, the analog input signals must first be

converted. This is performed internally in the PCM in

an analog-to-digital converter (A/D converter).

Inductive input signals

Inductive input signals are pulsed signals that transmit

information about the engine speed and reference mark.

Example:

• CKP sensor

The inductive signal is processed in an internal PCM

circuit. Interference pulses are suppressed and the pulsed

signals are converted into digital square-wave signals.

Digital input signals

Digital input signals have only two states:

• ON or OFF.

Example of digital input signals:

– Speed sensor pulses of a Hall sensor (VSS (Vehicle

Speed Sensor)).

These signals can be processed directly by the

microprocessor.

E51118

1

2

b

b

a

a

PWM signal

Fixed frequencya

Variable switch-on timeb

Signal voltage1

Time2

The microprocessor transmits output signals to the

actuators via specific output stages. The output signals

for the actuators can also have different forms:

• Switch signals (switch actuators on and off, such as

the A/C clutch),

• PWM (Pulse Width Modulation) signals. PWM

signals are square-wave signals with constant

frequency, but variable switch-on time. Using these

signals electro-pneumatic transducers, for example,

can be actuated at any location (for example the

boost pressure control solenoid valve or EGR

solenoid valve).

The high-performance components for direct actuation

of the actuators are integrated in the PCM in such a

manner that very good heat dissipation to the housing

is ensured.



Integrated diagnosis

In the case of sensor monitoring, the integrated

diagnostics are used to check if there is sufficient supply

to the sensors and whether their signal is in the

permissible range.

Furthermore, it is possible to check whether a sensor

signal is within the permissible range via the control

program in the PCM.

In the case of systems which work by means of a closed

control loop (the EGR system, for example), deviations

from a specific control range are also diagnosed.

A signal path is deemed to be defective if a fault is

present beyond a predefined period. The fault is then

stored in the fault memory of the PCM together with

freeze frame data (for example ECT, engine speed, etc.).

Back in working order recognition is implemented

for many of the faults. This entails the signal path being

detected as intact over a defined period of time.

Fault handling: If there are deviations from a

permissible set value for a sensor, the PCM switches to

a default value. This process is used, for example, for

the following input signals:

• ECT, IAT,

• MAP, BARO,

• MAF.

For some driving functions with higher priority (for

example APP sensor), there are substitute functions

which, for example, allow the vehicle to continue to be

driven to the next Authorized Ford Dealer.

Diagnosis

The PCM performs self-monitoring to ensure correct

operation. Malfunctions in the hardware or software of

the PCM are displayed by means of a DTC (Diagnostic

Trouble Code). Additional monitoring (see below) is

also performed.

Reference voltage monitoring:

• In the case of reference voltage monitoring, so-called

comparators compare the individual reference

voltages for the relevant sensors programmed in the

PCM to check if they are within limits.

• If a set reference voltage of 5 V falls to below 4.7

V, a fault is stored and the engine is stopped.

EEPROM (Electrically Erasable Programmable

Read Only Memory) monitoring:

• The engine adjustment data and freeze frame data

are stored in the EEPROM.

• The freeze frame data forms part of the EOBD.

Incorrect entries are detected appropriately and

indicated by a DTC.

Vehicles with EOBD


• Since the engine is stopped in the event of a fault,

this is non MIL active monitoring.



• Faults are MIL active, as the freeze frame data forms

part of the EOBD.

IDM (two-module system)

E47822

NOTE: If the IDM has been programmed with the latest

software version using WDS, ensure that the PCM is

programmed with the latest software version as well. If



this was not done automatically at the re-programming

stage, then it must be done manually immediately.

Otherwise increased combustion noise, increased fuel

consumption and black smoke emissions may result.

NOTE: When re-programming the IDM, ensure that

the correction values for the fuel injectors are also

entered. If this is not done, then it is not possible to start

the engine afterwards.

The IDM is an intelligent fuel actuator.

It processes information on the injected fuel quantity

and injection timing from the PCM and actuates the

fuel injectors accordingly.

The following sensors are connected directly to the

IDM:

• CKP,

• CMP,

• Fuel temperature sensor,

• KS,

• Fuel pressure sensor,

• BARO sensor.

Some of this information is made available to the PCM

via the CAN data bus for injection calculations.

However, the engine speed signal, which has already

been digitized by the IDM, is sent directly to the PCM

via a separate cable. This is because the engine speed

signal has high priority, as it is used for calculating the

injected fuel quantity and the injection timing.

The BARO sensor is integrated in the IDM and is used

to adapt the boost pressure and injected fuel quantity.

However, the BARO sensor is only used in the

calculations if a variable geometry turbocharger is

installed.



Delphi PCM (single-module system)

1 2

3

E37365

EEC V PCM1

IDM2

Delphi PCM3

Ford diesel vehicles with Delphi common rail injection

systems are gradually being fitted with just one PCM.

A separate IDM is no longer installed.

The components and functions of the EEC V PCM and

the IDM are integrated in the Delphi PCM. This is

referred to as a so-called single-module system.

The engine management and fuel injector actuation

strategies are identical with those of the engine

management system with the EEC V PCM and IDM,

the so-called two-module system.

Vehicles with coated diesel particulate filter

Note:

• After replacing the PCM following a PCM crash



replace the diesel particulate filter. In this regard,

always refer to the instructions in the current Service

Literature.



Glow plug control

E47824

1

2

34

5

6

7

7

7

7

6

CHT signal1

CKP2

PCM3

Glow plug warning indicator4

Sheathed-type glow plug relay (in CJB (Central

Junction Box))5

Parallel connected fuses (50 A each)6


Glow plug warning indicator

Note:

• On vehicles without EOBD the glow plug warning

indicator has a second function: If it flashes during

driving then it is operating as a fault lamp, informing

the driver there is a fault in the engine management

system.

• The glow plug warning indicator also serves as a

fault lamp on vehicles with EOBD. However, in this

case, it only indicates faults in the engine

management system which are not significant for

emissions.

• The glow plug warning indicator is switched

independently of the actual glow plug control. It

does not therefore indicate anything about the glow

plug status. It is therefore also not discernible from

the glow plug warning indicator whether, for

example, one or more glow plugs are not functioning.

Function

A glow plug control system is incorporated in the PCM.

It is divided into two areas.

Preheating

The PCM receives the relevant temperature signal from

the CHT sensor.

The length of the preheating period depends on the

temperature signal (low temperature = longer preheating

period).

The driver is informed of preheating by the lit glow plug

warning indicator in the instrument cluster.



Post heating

Preheating is followed, after engine start, by the post

heating phase.

Post heating helps to reduce engine noise, improve

idling quality and reduce HC emissions through more

efficient combustion just after start-up.

The post-heating phase is carried out up to an engine

speed of approximately 2,500 rpm.

The post-heating phase is interrupted when engine speed

exceeds 2,500 rpm. The service life of the glow plugs

is increased as a result.

Effects of fault (engine cold)

longer starting process

loud combustion noise after starting

rough engine running,



CKP sensor

Function

E47825

The CKP sensor records inductively the exact angular

position of the crankshaft as well as the engine speed.

Sensor ring for the CKP sensor

E47826

1

A B

1

Sensor ring, 2.0L Duratorq TDCiA

1.8L Duratorq-TDCi sensor ringB

Gap in the sensor ring1

The CKP sensor scans a sensor ring with 60–2 teeth.

The gap is located 90 degrees before top dead center of

cylinder 3 and is used by the engine management system

as a reference mark for the crankshaft position.

The CKP signal is used:

• to determine engine speed,

• to synchronize with the CMP signal,

• to determine the crankshaft position.


SensorsLesson 2 – Delphi-Common RailSystem

Effects of faults

If there is no signal, the engine cannot be started or cuts

out.

If the engine does not start, an oscilloscope can be used

to check to see if the CKP signal is present when the

engine is started.

A frequent cause of starting problems is rust on the CKP

sensor and/or on the sensor wheel. Even slight deposits

of rust can affect the signal.

Trouble code "Fuel pressure too high"

• External interference (coming from other electrical

sources) can have a negative effect on the CKP

signal. This can result in the signal peaks of the CKP

sensor being higher than they actually ought to be.

• The result is that, for example, instead of the system

specifying a fuel pressure of 200 bar for engine

starting, a fuel pressure of 600 bar is calculated

instead and then requested.

• This fuel pressure request is detected as implausible

by the system, whereupon the PCM sets the injected

fuel quantity to 0. The engine is therefore prevented

from starting.

• The reason for this is that the CKP signal is

transferred unfiltered from the IDM to the PCM and

is therefore more susceptible to both internal

interference (i.e. from the system itself) and external

interference.

• If a fault of this type occurs, switch ignition to OFF

for 3 seconds and then switch on again, repeat

starting procedure.

Diagnosis

If a specified maximum time is exceeded after the last

CKP signal, there is a fault (plausibility check). This

check is capable of analyzing driving errors (engine

stalling or cutting out).

Emissions-related component (vehicles with EOBD):

• No (Non MIL active)

CMP sensor

Function

E47827

The CMP signal is required by the IDM/PCM to activate

the individual fuel injectors according to the injection

sequence. The CMP sensor works on the Hall principle.

The square-wave signal is used to identify cylinder 1,

in conjunction with the CKP signal.

Effects of faults

During the engine start the CKP signal and the CMP

signal are synchronized. If the CMP signal is not

detected by the engine management system, no start

release is issued. This means the injected fuel quantity

is set to 0.

In the vehicles used, two different synchronization

strategies are implemented in the engine management

software.

Strategy 1:

• If the CKP signal fails while the engine is running,

the engine cuts out immediately and it is not possible

to re-start it.



Sensors

Strategy 2:

• If the signal fails while the engine is running, the

engine continues to run without restrictions.

However, it is not possible to re-start the engine after

it has been switched off.

Diagnosis

Parallel to the CKP signal the CMP signal occurs. After

it has been ensured that the CKP signal is OK, the

system is able to ascertain a fault in the CMP circuit.



MAP/IAT and T-MAP sensor

Depending on the system, either a MAP sensor and an

IAT sensor or a T-MAP sensor is installed. In the

T-MAP sensor, the MAP sensor and the IAT sensor are

combined to form a single component.

Function

The T-MAP sensor is shown in the diagram.

E47839

The boost pressure in the intake manifold is measured

by means of the MAP sensor. The higher the boost

pressure, then the greater the maximum quantity of fuel

that can be injected as a function of accelerator pedal

position or engine load.

The MAP signal influences the following functions:

• Injected fuel quantity,

• EGR system,

• turbo control.

The IAT sensor measures the intake air/charge air

temperature.

The signal serves as a correction factor to take into

account the effect of temperature on the density of the

charge air.

The IAT signal influences the following functions:


• Injection timing,

• EGR system.

Possible consequences of faults (MAP)

A faulty MAP signal leads to restricted operation of the

boost pressure control as well as the EGR system. The

injection quantity must therefore be reduced (reduced

engine power output).

Possible consequences of faults (IAT)

In the event of a signal failure, the PCM performs the

calculations using a predetermined substitute value. This

can lead to loss of power.

Diagnosis (MAP and IAT)

The monitoring system checks:

• the sensor for short circuit to ground/battery and

open control loop.

• the sensor for illogical voltage jumps (illogical

voltage jumps could indicate a loose connection, for

example).

• whether the output signal corresponds to the map

data.




• Yes (MIL-active)

CHT sensor

Function

Example of installation position of the CHT sensor on the

2.0L Duratorq-DI

E47840

1

2

1

3

Cylinder head1

Sensor tip2

CHT sensor3

The CHT sensor (CHT = Cylinder Head Temperature)

replaces the ECT sensor and the temperature sensor for

the temperature display in the instrument cluster.

The CHT sensor is screwed into the cylinder head and

measures the temperature of the material instead of the

coolant.

As a result, when the engine overheats (e.g. due to loss

of coolant) a more precise temperature measurement is

possible.

Note: Once removed, the CHT sensor must always be

replaced with a new one, and the specified tightening

torque must be observed exactly. Otherwise damage to

the sensor (e.g. through deformation of the sensor tip)

cannot be ruled out.

The CHT sensor is a thermistor, i. e. a negative

temperature coefficient resistor (NTC resistor).

E47841

J

J

1

2

3

5

8

4

6

7

PCM1

Second resistor ("pull-up")2

First resistor3

CHT sensor (NTC)4

Sensor output signal5

Analog/digital converter6

Microprocessor7

For comparison: ECT sensor8

The output signal is an analogue voltage signal which

behaves inversely proportional to the material

temperature and proportional to the resistance.

The voltage signal is digitized in the analog/digital

converter and transmitted in the form of counts to the

microprocessor, which assigns these to the

corresponding temperature values.



Sensors

At high temperatures, the resolution of the CHT sensor

is not enough to sufficiently cover the entire temperature

range from –40 °C to +214 °C. Therefore the

temperature curve is shifted by switching on a second

resistor in the PCM.

E47842

-- --

(129)

A B

C

12

32

CountsA

Voltage (V)B

Material (sensor) temperatureC

First curve1

"Pull-up" resistor switch point2

Second curve3

The first curve ranges from a material temperature of

-40 °C to approx. +78 °C. A transistor in the PCM then

activates a second, so-called "pull-up" resistor to extend

the sensor signal function. The second curve ranges

from a material temperature of approx. 62 °C to 214 °C.

Example: A sensor output voltage of 2.5 V

(= 500 counts) can indicate a material temperature of

35 °C and 124 °C (see diagram), depending on which

curve the voltage value is assigned to. When the

"pull-up" resistor is activated, the microprocessor

assigns the numerical value "500 counts" to the second

characteristic curve. This means that the material

temperature is in the higher temperature range (in this

case 129 °C).

Use of the CHT signal:

• Injected fuel quantity

• Start of injection

• Idle speed

• Glow plug control

• EGR system

• Actuation of the temperature gauge and glow-plug

warning indicator

Effects of faults

Open control loop:

• In an open control loop, the system assumes a

maximum temperature value of 120 °C.

• In this instance, the cooling fan(s) will be running

continuously and the engine will be operating at

reduced power (reduced injected fuel quantity).

Short circuit:

• If there is a short circuit, the system assumes a

temperature of > 132 °C.

• In this situation, the engine cuts out or cannot be

started.

If the sensor malfunctions or the engine overheats, the

engine overheating safety function is activated.

In this mode, engine power is reduced by injecting less

fuel. If the engine temperature increases further, then

the engine power is reduced further (depending on the

vehicle version).

Note: To avoid engine damage, it is not possible to start

the engine at a Cylinder Head Temperature below

–35 °C. The reason for this is the large quantities of fuel

injected, which in this case might result in components

being destroyed. Vehicles for cold climates have special

strategies or engine preheating equipment.



Diagnosis



open control loop.



example).

• the signal for a plausible temperature increase.



MAF sensor

Function

E47843

The MAF sensor works according to the hot wire

principle.

The MAF sensor is used exclusively to regulate exhaust

gas recirculation EGR (closed control loop) and not for

fuel metering, as is the case in petrol engines.

Effects of faults

If the signal from the MAF sensor fails then the EGR

rate is regulated using an emergency running map.

However, this means that the EGR rate is not regulated

closely to the operating limit, and as a result is outside

the limits.

Diagnosis



open control loop.



example).

• whether the output signal of the MAF sensor

corresponds to the map data.



VSS

Function

NOTE: The VSS is no longer installed on newer

vehicles with manual transmission. On these vehicles

the vehicle speed is provided via the ABS (Anti-lock

Brake System).

E47844

The VSS works on the Hall-effect principle of operation

(not on the Transit) and delivers a square-wave voltage

signal whose frequency is proportional to the current

vehicle speed.

The signal is used:

• to calculate the selected gear,

• as information for the trip computer,



Sensors

• as information on vehicle speed for the instrument

cluster,

• as information for the speed control system

incorporated in the PCM.

Effects of faults

increased idling speed

uncomfortable juddering when changing gears

Diagnosis

The input signals of the sensor are continuously checked

to ensure that they are functioning correctly.



APP sensor

E47845

Location

Integrated into the accelerator pedal

Function

The PCM needs the accelerator pedal position in order

to control engine power according to driver input.

The APP sensor houses a total of three sliding contact

potentiometers.

Effects of faults

Failure of a potentiometer has no influence on engine

operation. Only one DTC is (as a rule) stored in the fault

memory.

If two or three potentiometers fail, continued driving is

only possible at engine idle speed.

Diagnosis



open control loop.

• the values of the individual potentiometers for

plausibility.





KS

Function

E47865

1

43

2

Fuel injector1

IDM or PCM2

KS3

Pilot injection and main injection4

The KS sensor registers increased vibrations arising as

a result of increased combustion noise.

The signal is used by the IDM as a correction factor for

adapting the fuel quantity for pilot injection and for the

main injection.

Correcting the amounts of injected fuel adaptively

minimizes combustion noise over the entire service life.

Note: The range in which pilot injection can be carried

out is restricted by physical/mechanical limits. This

means that pilot injection is deactivated above a specific

engine speed and/or engine load has been reached.

Effects of faults

Open control loop:

• If the control reverts to open loop then the pilot

injection is switched off, which will result in louder

combustion noise being audible.

Short circuit:

• If there is a short circuit, the engine cuts out. It is

possible to start the engine, but it cuts out again after

a short while.

Diagnosis



open control loop.



Fuel temperature sensor

Function

E47847

The fuel temperature sensor is located in the fuel supply

system on the rear of the high-pressure pump.

It measures the fuel temperature in the low-pressure

system.

With the aid of this signal, the fuel temperature can be

continually monitored to prevent the fuel system from

overheating.



Sensors

Effects of faults (blue fuel temperature sensor)

Open control loop:

• The system assumes a temperature of 39 °C; the

result is irregular, rough engine operation.

Short circuit:

• If there is a short circuit, the system assumes a

temperature of over 90 °C (i.e. above the maximum

permissible fuel temperature). In this case, the system

assumes that the high-pressure fuel system is

overheating. The engine cuts out or cannot be started.

Effects of faults (green fuel temperature sensor,obsolete)

In both cases, i.e. a short circuit or open control loop,

the engine cuts out or cannot be started.

Diagnosis



open control loop.



Fuel pressure sensor

Function

E47848

The fuel pressure sensor measures the current fuel

pressure in the fuel rail very accurately and quickly and

delivers a voltage signal to the IDM in accordance with

the current pressure level.

The fuel pressure sensor signal is used to:

• determine the injected fuel quantity,

• determine the start of injection,

• drive the fuel metering valve on the high-pressure

pump.

Effects of faults

The fuel pressure is a critical value. If the signal should

fail, it is no longer possible to carry out a controlled

injection process.

Short circuit/open control loop:

• In this case the IDM assumes a pressure of more than

2000 bar. In response, the injected fuel quantity is

set to 0 and the engine cuts out or cannot be started.

The injected fuel quantity is also set to 0 if values are

implausible.

Diagnosis


• for short circuit to ground/battery and open control

loop,

• for plausibility (required pressure from the timing

map to the pressure actually set).



Fuel pressure outside the specified range

The engine management system continually compares

the fuel pressure request (calculated by the system) and

the actual fuel pressure in the fuel rail (measured by the

fuel pressure sensor).



If the system is working properly, the two parameters

will be within ± 50 bar of each other.

If they differ by more than -50 bar (for example the

required fuel pressure = 350 bar, but the actual fuel

pressure = 290 bar), the fuel quantity to be injected is

set to 0 and the engine cuts out or cannot be started.

The reason for this is that if the pressure difference is

outside the tolerance, it is no longer possible to carry

out a controlled injection process.

The cause may be faulty fuel pressure measurement or

faulty fuel metering; however, it is also possible that

there could be a leak at the fuel injector solenoid valve.

If there is a leak at the fuel injector solenoid valve, the

fuel that has leaked is conveyed via the leaking solenoid

valve into the leak-off pipe.

The result is an increased quantity of leak-off fuel,

which is supplied to the fuel return line via the leak-off

pipe.

This increased quantity of leak-off fuel can be measured

using a special tool (a measuring container for each fuel

injector) which is connected to the leak-off pipes of

each individual fuel injector.

After carrying out the measurement as specified (see

current Service Literature), it is possible to tell from the

individual quantities of leak-off fuel, whether there is

a leak at the fuel injector solenoid valve and which fuel

injector it belongs to.

A difference of more than +50 bar might indicate a

blocked fuel injector. A blocked fuel injector is not able

to open fully as required.

This means that it is not possible to fully reduce the

pressure in the fuel rail as calculated. As soon as the

difference in pressure rises above +50 bar, the quantity

injected is set to 0.

Position sensor in vacuum-operatedEGR valve

Function

E47849

A position sensor is integrated in the EGR valve, which

records the instantaneous position of the valve and

reports it back to the PCM.

A position sensor is usually provided as follows.

• Emission standard III: Only in conjunction with a

fixed turbocharger (no guide vane adjustment) – in

this case, no MAF sensor is installed.

• Emission standard IV: In conjunction with a

variable geometry turbocharger (electrically actuated

guide vane adjustment). The position sensor, along

with the MAF sensor, provides feedback on the

quantity of recirculated exhaust gas.

Values

Reference voltage: 5 V

The position sensor in the EGR valve operates in a

voltage range from 0 to 5 V.



Sensors

Effects of faults

Increased emissions of black smoke

The EGR system is switched off.

reduced engine power output

Diagnosis



open control loop.

• logical rise/fall rates of the signal. The sliding contact

is thus checked for faults (e.g. due to dirt). This type

of malfunction can also indicate a loose connection

(e.g. on the wiring harness connector).

• for plausibility: A seized or sticking EGR valve is

detected in this manner.



Position sensor in electric EGR valve

The position sensor is incorporated in the electric EGR

valve. For information on this, see "Electric EGR valve"

in the section on "Actuators".



Stoplamp switch/BPP switch

Function

E47850

1 2

BPP switch1

Stoplamp switch2

The signal from the stoplamp switch affects fuel

metering when the brake is actuated and when a gear is

engaged when idling.

Example: During braking, the PCM receives a signal

from the stoplamp switch which results in the fuel

quantity for idle control being reduced. This prevents

the idle control system from continuing to maintain idle

speed and thus counteracting the braking action.

On vehicles equipped with a speed control system there

is a further BPP switch on the pedal support bracket.

Its only function is to switch off the speed control by

actuating the brake.

CPP switch

Function

E47851

Using the CPP switch, the PCM identifies whether the

clutch is engaged or disengaged.

The quantity of injected fuel is briefly reduced during

actuation of the clutch to avoid engine judder during

gearshifts.

The CPP switch is located on the pedal box assembly.

On vehicles with a speed control system, the CPP switch

switches off the speed control system when the clutch

is disengaged.

Effects of faults

Engine judder during gearshifts.



Switch

Fuel metering valve

Function

E47852

The fuel metering valve regulates the quantity of fuel

fed to the high-pressure chamber of the high-pressure

pump as a function of fuel pressure in the fuel rail in

accordance with the fuel requirements.

As a result, the quantity of fuel that flows back to the

fuel tank is kept to a minimum.

E47853

1

1

2

Transfer pressure1

To the high-pressure chamber of the

high-pressure pump2

NOTE: The fuel metering valve operates together with

the fuel pressure sensor (on the fuel rail) in a closed

control loop.

The fuel metering valve is controlled by PWM signals

from the IDM. The type of pulse width modulation is a

function of:

• Driver's requirements

• Fuel pressure requirement

• Engine speed

The fuel metering valve is fully opened in its

de-energized state.

Effects of faults

In the event of a fault, the injected fuel quantity is set

to 0 and the engine cuts out or cannot be started.

Malfunctions in the fuel metering valve are detected by

continually comparing the fuel pressure request

(calculated by the system) and the actual fuel pressure

(measured in the fuel rail). If there is a discrepancy of

more than ± 50 bar, the injected fuel quantity is set to

0 and the engine cuts out or cannot be started (see also

section on "Fuel pressure outside range").

Diagnosis


– the sensor for short circuit to ground/battery and

open control loop.

– Note: The fuel metering valve is part of the fuel

pressure regulating system (see also the section on

"Fuel pressure control").




ActuatorsLesson 2 – Delphi-Common RailSystem

Fuel injector solenoid valve

Function

E47854

3

1

2

Valve needle1

Solenoid valve spring2

Solenoid valve3

The fuel injectors are each fitted with one solenoid

valve. Actuation for fuel metering is carried out by the

IDM.

Current is applied to the solenoid valves in two stages.

At the beginning of an injection process, the solenoid

valve is actuated with a higher pick-up current

(approximately 12 A) so that it opens quickly.

E47855

1

2

3

4

Current (in A)1

Pick-up current2

Holding current3

Time4

After a specified time, the pull-in current is reduced to

a lower holding current (approximately 6 A).

Unnecessary heat generation in the IDM is prevented

in this way.

The injected fuel quantity is now determined by the

opening period and the pressure in the fuel rail. The

injection process finishes when the current supply to

the solenoid valve is interrupted and the injector needle

then closes.

Adapting the fuel injectors

Because the mechanical tolerances of the fuel injector

solenoid valves change in the course of their service

life, the IDM has to be adapted at regular intervals to

take account of the changed fuel injector tolerances.

Adaptation is done individually for each cylinder over

a period of 900 seconds per cylinder. The individual

adaptation processes are performed in the same order

as the firing sequence. The process is started with

cylinder 1.



Actuators

For adaptation to be carried out, the following conditions

must be met:

• Engine temperature at least 70 °C,

• Engine speed between 1800 and 3500 rpm,

• Vehicle speed between 50 … 70 km/h.

If this range is left during an adaptation process (i.e. the

conditions are no longer satisfied), the adaptation

process is stopped and then continued again when the

values are once more within the range.

The pilot injection is deactivated when the adaptation

is taking place.

The IDM sends the fuel injector solenoid valve an

injection signal with a period of time (e.g. 8 ms) stored

in the map.

The IDM can determine from the power consumption

of the solenoid valve whether the solenoid valve can

carry out the commands of the IDM or whether it is

responding more quickly (for example in 7 ms) or more

slowly (for example in 10 ms). The power consumption

of the solenoid valve therefore acts as a reference to the

signal sent by the IDM.

If there is a discrepancy between the signal sent and the

response of the solenoid valve, an adaptation process

must be carried out in the adaptive map tables.

NOTE: During the adaptation process, the injection

signal is so short that the injector needle is not raised

to inject any fuel. The result: during this period misfires

occur and may be noticed in the aforementioned engine

speed and vehicle speed range.

Note: Concerns may result if, in extreme cases, the

operating conditions that would allow an adaptation

process to take place, have not occurred for a long time.

These concerns may relate to:

• rough engine running,

• increased emissions of black smoke,

• loud combustion noise.

After the adaptation process has been completed for one

cylinder, the process then continues with the next

cylinder (in accordance with the firing sequence).

Effects of faults

rough engine running

increased emissions of black smoke

loud combustion noise

Fuel pressure out of range (see corresponding section

in this brochure).

Diagnosis

Monitoring includes recording of general faults during

fuel metering (relating to all 4 cylinders) and of

individual faults (relating to a cylinder).

By comparing the KS signal with the relevant timing

map, it is possible to determine faults during the fuel

metering as well as a complete failure of a fuel injector.

Faults, such as short circuits or open circuits in the

wiring circuit of the fuel injectors, are determined by

an electronic check in the PCM.

If a fuel injector has failed, the engine continues to run

in emergency mode on three cylinders with reduced

output.


• No (Non-MIL-active) if fault leads to engine being

switched off.

• Yes (MIL-active), for faults in the fuel metering.



EGR solenoid valve and boost pressurecontrol solenoid valve

Function

E47856

1 2

EGR solenoid valve1


NOTE: The EGR solenoid valve and boost control

solenoid valve each operate in a closed control loop (see

section on "EGR system" or "Boost pressure control"

in this brochure).

The solenoid valves are supplied with a vacuum by the

vacuum pump.

The signals from the PCM control this vacuum, as a

result of which the boost pressure is regulated by means

of a vacuum unit and the EGR flow is regulated by the

EGR solenoid valve.

The current of these signals determines the vacuum

which is sent to the EGR solenoid valve or to the

turbocharger vacuum unit.

Effects in the event of a faulty EGR solenoidvalve

The EGR system is switched off.


increased emissions of black smoke

Effects in the event of a faulty boost pressurecontrol solenoid valve


Diagnosis


• the relevant solenoid valve for short circuit and open

circuit.

Components significant for emissions (vehicles with

EOBD):


Intake manifold flap and intakemanifold flap solenoid valve

Function

E47857

6 5

1 2

34

Intake manifold1

Intake manifold flap2

Intake manifold flap solenoid valve3

Vacuum unit4

PCM5

Ignition lock6

Diesel engines have a high compression ratio. The high

compression pressure of the intake air affects the

crankshaft via the pistons and connecting rods and

causes judder when the engine is stopped.



Actuators

The intake manifold flap solenoid valve connects the

vacuum for the vacuum unit of the intake manifold flap

in the intake manifold, as a result of which the intake

manifold flap is closed. This prevents engine judder

when the engine is stopped.

The intake manifold flap solenoid valve is energized

when the engine is stopped. As a result, the vacuum to

the vacuum unit for actuating the intake manifold flap

is released and the intake manifold flap is closed briefly

as a result.

If the signal fails, or if the intake manifold flap solenoid

valve fails, the intake manifold flap remains open when

the engine is stopped.

Vehicles with diesel particulate filter

See section on "Coated diesel particulate filter" in this

lesson.

Effects of faults

Intake manifold flap jams open:

• Starting and engine running are not adversely

affected.

• However, when the engine is stopped, it judders

severely.

Intake manifold flap jams closed:

• Engine does not start.

Diagnosis



circuit.



Electric EGR valve (certain versionsonly)

E70245

NOTE: After the EGR valve is replaced or after the

PCM is replaced/reprogrammed, the EGR valve must

be initialized using the PCM (refer to the instructions

in the current Service Literature).

Various versions are equipped with an electric EGR

valve.

The EGR rate can be metered out more accurately by

the electric EGR control.

Function

The electric EGR valve comprises the following

components:

• Servo motor,

• Position sensor,

• the EGR valve itself.

The servo motor is a DC motor which is driven via

PWM by the PCM.

The position sensor is a sliding contact sensor which

supplies the PCM with an analogue voltage signal via

the position of the EGR valve.

Effects of faults

Malfunctions at the electric EGR valve result in the

EGR system being deactivated.



If the EGR valve jams open, the following symptoms

may occur:

• increased black smoke formation,

• irregular idling,

• engine judder,

• reduced engine power output.

Diagnosis

The monitoring system:

• checks the servo motor as well as the position sensor

for short circuit to ground/battery and open control

loop.

• checks the measured values of the position sensor

for plausibility.

• checks the EGR valve for unobstructed movement.

• detects a seized EGR valve.

The PCM performs a cleaning cycle after the engine is

stopped. For this purpose, the EGR valve is fully open

and closed a few times.





Actuators

Electrical turbocharger guide vane adjustment actuator

E46462

1

2

3


actuator1

Actuating lever2

Adjusting lever for guide vanes3



Diesel engines with the Delphi common rail system,

which are designed for emission standard IV, have a

variable geometry turbocharger, which is actuated via

an electrical turbocharger guide vane adjustment

actuator.

Its exact positioning for each operating state is achieved

by the electrical adjustment of the guide vanes. This has

a positive effect on exhaust emissions and helps to

achieve emission standard IV.

E46463

1

A B

2

3

4

5

6

7

Adjustment mechanismA

Control electronicsB

Servo motor1

Servo motor contact block2

Inductive sensor unit3

Drive shaft4

Worm gear5

Drive pinion6

Servo motor contacts7

The electrical turbocharger guide vane adjustment

actuator consists in total of the following two

components:

• Actuator unit

• Control unit

Actuator

The servo motor in the actuator unit operates the drive

shaft via a worm gear.

The drive shaft is connected to the guide vanes by the

actuating lever. Adjustment of the guide vanes is

achieved by moving the actuating lever.



Actuators

There is an inductive sensor element at the end of the

actuator unit drive shaft. When this drive shaft is turned,

an induced pulse-width modulated signal is created here,

by means of which the current angular position of the

guide vanes is exactly determined.

Control unit

The control unit controls the servo motor.

The control unit is connected to the PCM via the CAN

data bus. The angular position for the electrical

turbocharger guide vane adjustment actuator is

calculated by the PCM and is transmitted to the

electronic actuator unit via the CAN data bus.

The angular position of the guide vanes is recorded by

the inductive sensor element in the form of pulse-width

modulated signals and transmitted to the control unit.

There is a temperature sensor located in the control unit

of the electrical turbocharger guide vane adjustment

actuator, and if the maximum permitted temperature of

160 ± 9 °C is exceeded (e. g. through heating up in a

traffic queue), the servo motor is moved into the safe

position.

This means that the guide vanes are fully opened. This

prevents, in extreme cases, maximum turbocharger

pressure (almost closed guide vanes) being made

available by a possible heat induced seizure of the

mechanisms (caused by overheating).

Malfunctions in the electrical turbocharger guide vane

adjustment actuator are detected by the PCM via the

CAN data bus.

Effects of faults

In the case of a fault, the amount of fuel injected is

limited to max. 20 mg per injection to protect the

turbocharger and the engine from damage.

Diagnosis

Malfunctions are detected by the electrical turbocharger

guide vane adjustment actuator itself and transmitted

via CAN to the PCM.





Ignition ON strategy

When the ignition is switched on, the PCM is supplied

with voltage and switched on via the main relay.

Initially, the PCM checks all of the input signals for

correct function, including those from the ECT, MAP

and MAF (self-test).

Afterwards the key code is checked via the PATS

system. If this is OK, the start release is issued to the

system.

Note:

• On the two-module system a voltage is present at

the fuel injectors even if the start release has not been

issued by the PATS system.

• In a single-module system, there is no voltage

present at the fuel injectors if the PATS system does

not issue the start release.

After issuing the start release the PCM activates the

IDM (via the IDM relay).

As soon as the IDM is supplied with voltage, it also

checks all of the input signals, such as those from the

CKP, CMP and KS, for correct function (self-test).

If the IDM completes the self-test without finding any

faults, it sends an OK signal to the PCM via the CAN

data bus.

The engine can now be started.

Note:

• If the driver does not start the engine within a

specified period of time (approximately 12 seconds),

this is detected by the system as a fault and the

engine does not start.

• However, switching the ignition off and back on

issues the system with another start release.

Engine start strategy

The diagram shows the two-module system. On the

single-module system the IDM is integrated in the PCM.

E47910

1

4

2

3

IDM1

PCM2

CKP signal3

Separate IDM/PCM cable for transmission of

the CKP signal4

For the engine to start, the battery voltage must be > 9

V. In addition, a starter speed of 190 … 225 rpm

(depending on vehicle and engine version) is required.

During the starting process the PCM compares the

engine load map with the incoming sensor signals (CHT,

MAP, IAT).

At the same time the IDM compares the sensor signals

fuel pressure, fuel temperature, CKP and CMP with the

data in the map tables.

Afterwards the IDM sends the CKP signal via a

separate cable (already digitized) to the PCM.

The reason for the separate connection to the PCM (i.e.

bypassing the CAN data bus) is the high priority with

which the CKP signal has to be transmitted to the PCM.

This ensures that the injected fuel quantity and the

injection timing can be calculated as quickly as required.



Strategies

Note on checking the CKP signal if the engine does not

start:

• Using the WDS data logger, check in the "PCM"

section to see if the CKP signal is present. If it is

present, check in the "ICU" section to see if the

signal is also present here. If the signal is not present

here, the separate cable from the IDM to the PCM

may be faulty.

The diagram shows the two-module system. On the single-module system the IDM is integrated in the PCM.

E47911

5

8

7

10

9

6

1

4

3

2

Cam for identifying cylinder 11

CMP sensor2

CKP sensor3

Tooth gap on sensor ring for crankshaft position4

IDM5

Injected fuel quantity and injection timing6

Engine speed signal (already digitized)7

Separate cable to IDM/PCM8

PCM9

Synchronization of CKP-/CMP signal10

The CMP signal is transmitted by the IDM to the PCM

via the CAN data bus at the same time as the CKP

signal. In the PCM the CKP signal is then synchronized

with the CMP signal.


StrategiesLesson 2 – Delphi-Common RailSystem

Note:

• Synchronization is of greater significance for the

common-rail injection system. By comparing the

position of the crankshaft (CKP) and the camshaft

(CMP) cylinder 1 is identified and the injection

sequence is thus determined.

• Injection can only be carried out if synchronization

has been successfully completed (cylinder 1

identified).

• If the CMP signal is missing, the fuel injection

release is not issued, in other words, the engine does

not start.

In older vehicles (at the time of going to press) if the

CMP signal is missing no diagnostic trouble code is

stored in the system. In newer vehicles this has been

implemented into the strategy so that if the CMP signal

is missing a diagnostic trouble code is stored.

After synchronization has been completed successfully,

the PCM calculates the injected fuel quantity and the

injection timing.

Note:The PCM has a protective function. If the PCM

detects faulty input signals or other faults which could

result in damage or even destruction of the system, the

fuel quantity is set to 0 so that it is not possible to start

the engine.

The calculated injected fuel quantity, together with the

injection timing, is sent to the IDM as a complete block.

The IDM splits the block into specific pilot and main

injection quantities.

After the block has been split, a start release is issued.

Fuel is injected and the engine starts to fire.

Note:

• The engine is not yet idling!

• The engine is merely starting up.

Protective zone for dual mass flywheel atapproximately 400 rpm.

When an engine speed of 400 rpm is reached,

oscillation of the dual mass flywheel is particularly

high – there is a risk of damaging the dual mass

flywheel.

If for any reason this engine speed is not exceeded, the

system sets the injected fuel quantity to 0 and the engine

cuts out.

Faulty dual mass flywheel

A faulty dual mass flywheel (for example worn springs

in the dual mass flywheel) usually increases the

oscillations; these are also at their highest at an engine

speed of 400 rpm. This increase in oscillations is

detected by the CKP sensor. As a result, the system sets

the injected fuel quantity to 0 and the engine cuts out.

Monitoring of engine operation

The engine restriction check is active at engine speeds

between 450 ... 700 rpm. In this phase, the system

checks to see if the engine is running properly.

Besides a possible stiffness of the engine itself, the

running can also be braked by defective

components/ancillary components. Such defective

components/ancillary components could include:

• blocked A/C compressor,

• blocked power steering pump,

• faulty fuel injector, faulty engine component (engine

running on only three cylinders).

In this case, the injected fuel quantity is not increased

any further which means that engine speed does not

increase, even if the accelerator pedal is pressed.



Strategies

Idle strategy


E47937

9

6

4

3

1

2

5

7

8

Fuel injector1

CMP signal (with older software only)2

Injection signal (pilot injection and main

injection)3

IDM4

KS5

CKP sensor6

APP sensor7

CHT sensor8

PCM9

Once the engine speed range of the engine restriction

check has been exceeded, the system goes into idling.

At idle speed (actual idle speed depends on the vehicle),

a fuel pressure of approximately 250 bar is available.

During idling, the main input parameters for the PCM

are, in addition to the CKP signal, the CHT signal and

the APP signal.

The main input parameter for the IDM is the signal from

the KS. Combustion noise is monitored very closely,

particularly when the engine is idling, to ensure the

engine runs as quietly as possible. This takes place

through the optimized adaptation of the injected fuel

quantity for pilot injection.

Idling operating temperatures are reached from:

• 60 ... 75 °C on the Ford Transit,

• 70 ... 75 °C on the Ford Focus and Ford Mondeo.

Idle speed control

The fuel consumption at idle is mainly determined by

idle speed and efficiency.

It is advantageous to have as low an idle speed as

possible, as idling is of considerable importance when

driving in dense traffic (for minimizing fuel

consumption).



However, the selected idle speed must be sufficient to

ensure that, under any conditions (e.g. when the air

conditioning is switched on, or the vehicle electrical

system is heavily loaded), it does not drop so low that

the engine starts to run roughly or stalls.

To regulate the idle speed, the injected fuel quantity is

varied by the idle speed controller until the measured

actual engine speed is the same as the specified target

engine speed.

The specified engine speed and the control characteristic

are influenced by the CHT.

Other parameters are:

• vehicle speed (engine speed compensation system),

• generator control (smart charging) - this can raise

the idle speed,

• speed control system.

Fuel metering calculation


E47858

1

4

7 6

2

5

3

Pilot injection and main injection fuel quantity1

IDM2

PCM3

Fuel injector4

CKP sensor5

CHT sensor6

Injection signal7

Diesel engines normally run without the use of a throttle

valve and therefore always operate with an excess of

air.

The torque or power output of the diesel engine is only

changed by the amount of fuel that is made available

(injected fuel quantity).

Two different strategies are used when calculating the

fuel metering:

• engine starting,

• engine running.



Strategies

Starting fuel quantity

When starting the engine, the injected fuel quantity is

calculating as a function of Cylinder Head

Temperature and engine speed. The starting fuel

quantity is delivered from the time the ignition is

switched on until a specific minimum engine speed is

reached. The driver does not have any influence on the

start quantity.

Driving



E47859

1

4

2

5

36


IDM2

PCM3

Fuel injector4

CKP5

APP6

In normal driving mode, the injected fuel quantity is

calculated from the following main parameters:

• APP,

• Engine speed.

In addition, the calculation of the injected fuel quantity

is influenced by other parameters (correction

parameters), such as: engine temperature and boost

pressure.

E47860

1 2

6

3 45

Calculation of accelerator pedal actuation1

Judder damper2

Calculation unit3

Limiter4

Signal to the injection pump5

Idle speed calculation6

While the engine is running, the PCM uses one of the

following two calculations as a basis for fuel metering:

• idle speed,

• accelerator pedal actuation.

Both calculations are performed continuously in parallel

and independently of each other.

The values calculated from idle speed and accelerator

pedal actuation are compared with each other by a

calculation unit.

This calculation unit then decides which calculation

(idle speed or accelerator pedal actuation) should be

used as the output signal for the injection pump. The

calculation unit always chooses the larger value for the

injected fuel quantity.

Example: Engine cold – the idle speed calculation yields

an idle speed of 1,200 rpm and an injected fuel quantity

of 7 mg. The accelerator pedal is pressed by a very small

amount, and the accelerator pedal calculation provides

an injection quantity of 6 mg. As the value from the

accelerator pedal calculation is lower than the result for

the idle speed calculation, the idle speed calculation

has higher priority. If the accelerator pedal is moved



further, and the accelerator pedal calculation provides

a higher injected fuel quantity (> 12 mg) than the idle

speed calculation as a result, then the accelerator pedal

calculation takes priority.

Calculation of fuel metering when speed controlsystem is switched on

Example: The vehicle is traveling in 5th gear at a speed

of 100 km/h (62 mph) with an engine speed of 2,500

rpm. Under these conditions, the speed control system

is now switched on.

Of the previously mentioned parameters, it is the idle

speed calculation that determines the quantity of

injected fuel required to maintain the desired speed.

This means that the speed in this instance is measured

via the idle control system. If load conditions change

(for example if driving uphill) the system attempts to

maintain the speed accordingly.

Once again, as the accelerator is pressed more, the

accelerator pedal calculation assumes a higher priority

again. The idle speed calculation resumes its original

function until the next time the speed control system is

switched on.

Judder damper

Sudden actuation of accelerator

E47861

2

3

4

1

5

Engine speed1

Abrupt actuation of accelerator pedal (driver

demand)2

Engine speed curve without active judder

damping3

Engine speed curve with active judder damping4

Time5

There is a so-called software filter between the

accelerator pedal calculation and the calculation unit.

When the accelerator is actuated or released suddenly,

this causes huge changes in injected fuel quantity

requirements and thereby also in the torque produced.

Owing to this abrupt load change, unpleasant jerking

of the powertrain is caused in the elastic mountings

(engine speed fluctuations. These are reduced by the

judder damper as follows:

• as engine speed increases, comparatively less fuel

is injected, as engine speed decreases more fuel is

injected.

In addition, the software filter prevents an abrupt drop

in engine speed when changing gear.



Strategies

Smooth-running control (cylinderbalancing)

In addition to the previously described external load

moments, there are also combustion quality phenomena

and internal friction moments which need to be balanced

out. These change slightly, but continuously, over the

entire service life of the engine.

In addition, the individual cylinders do not generate the

same level of torque for the entire service life of the

engine. The reason for this are the mechanical tolerances

and changes which occur during the service life of the

engine. All this could result in a rough-running engine,

particularly at idle.

The smooth-running control system calculates the

accelerations of the crankshaft via the CKP sensor after

each combustion process and compares them.

Using the differences in engine speed as a basis, the

injected fuel quantity for each cylinder is adjusted

individually so that all the cylinders make as equal a

contribution as possible to the torque produced.

External fuel quantity intervention

In the case of external fuel quantity intervention, the

injected fuel quantity is influenced by another control

unit (for example traction control).

It informs the PCM if and how much the engine torque

and consequently the injected quantity needs to be

changed.

Controlling fuel injection

E47862

4

2

3

1

5

67

8

Top dead center1

Pressure curve without pilot injection2


Pressure curve with pilot injection4

Injector needle lift5

Injector needle lift for pilot injection6

Injector needle lift for main injection7

Crank angle8

The pilot injection brings about a preconditioning of

the combustion chamber and has the following effects

on this:

• The compression pressure is raised slightly by the

initial reaction or partial combustion process, as a

result of which the ignition lag for main injection is

shortened and the combustion pressure rise is

reduced (softer combustion).

These effects diminish the combustion noise and the

NOX emission.



Controlling the injected fuel quantity and theinjection timing



E47863

1

4

2

3


IDM2

PCM3

Fuel injector4

With the common rail injection system, a small injected

fuel quantity for pilot injection is injected into the

combustion chamber prior to the main injection.

In this system the PCM calculates the overall injected

fuel quantity and the injection timing.

Before the signal for the overall injected fuel quantity

and the injection timing is sent to the IDM, the PCM

determines the angle for the start of the pilot injection

and the main injection as well as the injected fuel

quantity for pilot injection.

Injection signal to the solenoid valve of the fuel injector

E47864

1 2

Interval between start of pilot injection and start

of main injectiona

Interval between pilot injection and main

injectionb

Injected fuel quantity for pilot injectionc

Injected fuel quantity for main injectiond

Pilot injection timing (degrees crank angle)1

Main injection timing (degrees crank angle)2

Example

• Overall injected fuel quantity 40 mm3,

• of which injected fuel quantity for pilot injection =

2 mm3.

• Start of main injection = 8 degrees before TDC,

• Start of pilot injection = + 9 degrees before TDC.

The IDM, based on the stipulations of the PCM,

generates the following signals for the fuel injector:

• Injected fuel quantity for main injection = 38 mm3,

• Injected fuel quantity for pilot injection = 2 mm3,

• Main injection timing = 12 degrees before TDC,

• Pilot injection timing = 17 degrees before TDC.

The timing of the pilot injection and main injection

is designed here to be variable. This means that the

timing and the duration of the pilot injection and main

injection can be optimally adapted to the operating

conditions.



Strategies

The noise and exhaust emissions are thereby kept to a minimum.

Controlling the fuel pressure

E47867

5

2

3 4

8

7

6

9

1

IDM/PCM1

High pressure pump2

High-pressure chamber3

Fuel supply4

Fuel metering valve5


Fuel rail7

Solenoid valve8

Injector needle9

The engine management system on the common rail

injection system is capable of providing the optimum

injection pressure for each operating condition.

Fuel is compressed via the high-pressure chamber of

the common rail high-pressure pump and supplied to

the fuel rail.

In the process, the delivery quantity is regulated by the

fuel metering valve by varying the opening cross section

of the fuel metering valve accordingly.

The fuel pressure is regulated in such a way that the

optimum pressure is available for each operating

condition.

On the one hand, this reduces the noise emission during

fuel combustion.



On the other hand, the engine management system can

meter the fuel very precisely, which has a positive effect

on exhaust emissions and fuel consumption.

The fuel pressure sensor continually informs the IDM

(two-module system) or the PCM (single-module

system) about the current fuel pressure.

Pressure is regulated via the fuel metering valve by

reducing or enlarging the cross section of this valve

accordingly. This means that a smaller or larger fuel

quantity is supplied by the high-pressure pump until the

desired fuel pressure has been reached.

Note:

• The fuel pressure depends on engine speed and

engine load. Depending on the engine load

requirements specified by the driver, it is possible

for the maximum fuel pressure to be available at an

engine speed of just 1500 rpm (depending on the

vehicle).

Diagnosis

E49613

12

3

3

4

4

5

High pressure pump1


Fuel rail3


PCM5

The following comprehensive tests are carried out:

• Measuring the differential pressure during engine

start (comparison between desired and actual fuel

pressure).

• Measuring the differential pressure during engine

running (comparison between desired and actual fuel

pressure).

The diagnostic system classifies faults in the fuel

metering system either

• as control faults, in other words the pilot injection

is switched off or

• as function faults, i.e. the engine is switched off.

Note: control faults can also be caused by defective fuel

injectors.



Strategies

Switching off the engine

Because of the way the diesel engine works, the engine

can only be switched off by interrupting the fuel supply.

In the case of the fully electronic engine management

system this is achieved by the PCM specifying "injected

quantity = 0". The corresponding fuel injection solenoid

valves are no longer actuated and the engine is switched

off.

Pressure drop after engine is switched off

The pressure reduction is achieved by applying a current

to the fuel injector solenoid valves at short intervals.

Each time, the pick-up current is enough to open the

control valves, but remains low enough not to lift the

injector needle and thereby cause an undesired injection

of fuel.

The pressure is completely dissipated within a few

seconds when current is applied to the solenoid valves.

After the engine is switched off, the pressure drop can

be heard in the form of a buzzing noise.

Note: Before opening the high-pressure system, follow

the safety precautions in the current Service Literature.

EGR system

E47869

2

85

1

9

7

4

3

6

10

EGR solenoid valve1

MAF sensor2

PCM3

Oxidation catalytic converter4



Turbocharger(s)5

EGR valve6

Vacuum pump7


Intercooler (not on all versions)9

EGR cooler (not on all versions)10

When turbochargers are used (they are deployed on all

the diesel engines described here), the temperatures in

the combustion chamber rise along with compression

and combustion power.

Combustion temperatures are increased even further by

the use of the direct injection process.

Both result in the increased formation of NOX in the

exhaust gas. In order to keep this NOX content in the

exhaust gas within required limits, an EGR system is

used.

In the part load range, exhaust gas recirculation is

achieved by mixing the exhaust gases with the intake

air. This reduces the oxygen concentration in the intake

air. In addition, exhaust gas has a higher specific heat

capacity than air and the proportion of water in the

recirculated exhaust gas also reduces the combustion

temperatures.

These effects lower the combustion temperatures (and

thereby the proportion of NOX) and also reduce the

amount of exhaust gas emitted. The quantity of exhaust

gas to be recirculated is precisely determined by the

PCM. An excessive exhaust gas recirculation rate would

increase soot, CO and HC emissions because of the lack

of air.

For this reason, the PCM requires feedback on the

recirculated amount of exhaust gases. Three different

systems are used which differ in terms of the following

components:

• Position sensor in the EGR valve (on engines with

a wastegate-controlled turbocharger, emission

standard III)

• MAF sensor (on engines with variable geometry

turbocharger, emission standard IV).

• MAF sensor plus a position sensor in the EGR valve

(on engines with a variable geometry turbocharger,

emission standard IV)

On all three systems the EGR valve is vacuum-actuated

by the EGR solenoid valve. The duty cycle with which

the EGR solenoid valve is actuated by the PCM

determines the vacuum applied at the EGR valve.

System with position sensor in the EGR valve

The position sensor in the EGR valve signals the current

position of the EGR valve to the PCM. From this, the

PCM can determine the instantaneous quantity of

recirculated exhaust gas depending on the MAP, thus

forming a closed control loop.

System with MAF sensor

The quantity of exhaust gas recirculated when the EGR

valve opens has a direct influence on the MAF sensor

measurement.

During exhaust gas recirculation, the reduced air mass

measured by the BARO sensor corresponds exactly to

the value of the recirculated exhaust gases. If the

quantity of recirculated exhaust gas is too high, the



Strategies

intake air mass drops to a specific limit. The PCM then

reduces the proportion of recirculated exhaust gas, thus


System with MAF and position sensor

Vehicles which meet emission standard IV use a

combination of two sensors (MAF and position sensor).

Here, the position sensor serves as an additional

correction parameter for the quantity of recirculated

exhaust gas. This means that the quantity of exhaust gas

can be metered even more accurately.

This way, it is possible to get even closer to the

operating limit with a greater quantity of exhaust gas,

as a result of which NOX emissions can be reduced

further.

Diagnosis

To check the EGR system, various prerequisites must

be satisfied:

• Engine running under certain operating conditions,

depending on engine temperature, intake manifold

pressure and engine speed.

• Required operating conditions must be maintained

for a certain time span.

During this time it is checked whether the required EGR

rate is within the limits.

If the required operating conditions are no longer met,

the monitoring is stopped. The data collected so far is

frozen. After reaching the operating conditions again

the test is continued.

If monitoring has been completed after the specified

period of time and no faults have occurred, further

monitoring of the EGR system does not take place until

the next drive cycle.

Faults in the EGR system have no serious effects on

exhaust gas emissions and are thus not MIL active.



Boost pressure control

The diagram shows the boost pressure system for a turbocharger with variable turbine geometry and solenoid valve

control

E47870

2

3

1

4

6

78

5


MAP sensor2

IAT sensor3


Vacuum unit for variable turbine geometry5

Turbocharger(s)6

PCM7

Vacuum pump8



Strategies

The figure depicts the charge air system of a turbocharger having variable turbine geometry and electrical turbocharger

guide vane adjustment actuator

E48186

1

2

4

5

3

T-MAP sensor1



actuator3

Turbocharger(s)4

PCM5

On a variable geometry turbocharger, the boost pressure

is regulated by adjusting the guide vanes. The optimum

boost pressure can therefore be set for every operating

condition.

The boost pressure actual value is measured via the

MAP sensor. The required value is dependent on the

engine speed and the injected fuel quantity as well as

the IAT and BARO correction factors.

In the event of a discrepancy, the guide vanes of the

variable geometry turbocharger are re-adjusted via the

boost pressure control solenoid valve or the electrical

turbocharger guide vane adjustment actuator.

In the event of a malfunction of the boost pressure

control system, engine power is reduced via the fuel

metering system.

With wastegate turbochargers (not shown here), the

MAP signal is used as a safety function if the wastegate

does not open after a specified boost pressure has been

reached. The engine power is also reduced in this case.



PCM fault strategy

E48114

12 3

456

78

PCM connector1

Microprocessor2

Operating memory (RAM)3

EEPROM memory4

PATS5

Power supply relay6

Fuse7

Battery8

NOTE: DTCs and adaptation data can be deleted

electronically with the aid of WDS.

NOTE: The PCM has a continuous voltage connection

to the battery. This is used, among other things, to

activate the PATS LED.

To store DTCs and other data, the PCM uses the

EEPROM memory on diesel engines.

The EEPROM memory is a non-volatile memory

(read-only memory) which means that the data contained

in it are retained even if the supply voltage is interrupted

(e.g. when the battery is disconnected).

During a journey, all new fault codes and engine

adaptation data (e.g. fuel adaptation data) are first stored

in the operating data memory (RAM) of the PCM.

After the engine is switched off, and at certain intervals

during operation, these data are then transferred to the

EEPROM memory. To ensure this happens, the power

supply relay remains activated for a further 1.2 seconds

after the ignition is switched off (power latch).

After the ignition is switched on, the DTCs stored in

the EEPROM are transferred back to the RAM memory.

Monitoring the system

The common rail engine management system has a triple

software monitoring system in the IDM, which brings

the engine to a standstill in the event of a critical

software error in the system. This triple monitoring

system works as follows:

• Deletes all injection operations still present in the

module,

• Closes the fuel metering valve to prevent any further

increase in fuel pressure in the fuel rail,

• Brief, intermittent actuation of the fuel injectors to

rapidly dissipate the fuel pressure.

In addition to the triple software monitoring system, a

module hardware monitoring system has been integrated

for monitoring the fault-free functioning of the

individual components of the IDM.

If the system detects a module hardware error, current

supply to the fuel injectors is interrupted.

After the engine has been switched off by the software

or hardware monitoring system, it is generally possible

to re-start the engine by switching the ignition OFF and

then ON.

The system software continually monitors the following

sensors/actuators to see that they are working properly:

• Fuel pressure sensor,

• CKP sensor,

• CMP sensor,

• Fuel metering valve.



Strategies

If one of these sensors fails or malfunctions, the engine

is stopped by the PCM.

In addition to sensor monitoring, the following situations

may result in the engine being switched off:

• Drop in pressure in the fuel rail because the fuel

injector opening period was longer than calculated

by the system (e.g. fuel injector sticking or dirty),

• Fault is detected via the pull-in current of the fuel

injectors.

The latter two situations do not require any additional

sensors or actuators in the system.

All the input parameters (sensors) of the PCM are

monitored for short circuits and open circuits.



Overview – diesel particulate filter

E70242

8

1

2

3

4

5

6

7


Catalytic converter exhaust gas temperature

sensor2

Flexible pipe3

Diesel particulate filter exhaust gas temperature

sensor4

Diesel particulate filter heat shield5

Diesel particulate filter6

Rear pipe – diesel particulate filter differential

pressure sensor7

Front pipe – diesel particulate filter differential

pressure sensor8




NOTE: After replacing the diesel particulate filter,

using WDS it is necessary to perform a supervisor

parameter reset as well as a reset of the parameters of

the diesel particulate filter differential pressure sensor

in PCM. In this regard, always refer to the instructions


A coated diesel particulate filter is used in certain

versions of the Mondeo 2001 (02/2006-).

The diesel particulate filter is shaped like a honeycomb

and is made from silicon carbide, similar to the diesel

particulate filter in the system with fuel additive (see

relevant section in this Student Information).

A passive regeneration of the diesel particulate filter

is possible at temperatures above 300 °C with the aid

of the coating (platinum ceroxide).

In this temperature range, the trapped diesel particulates

are converted catalytically.

The exhaust gas temperature required for passive

regeneration is often not attained. In this case, the

trapped diesel particulates must be burnt off from time

to time with the aid of an active regeneration process.

Passive regeneration

The exhaust gases flow through the walls of the silicon

element. In doing so, the diesel particulates remain

adhered to the ceramic wall that has been coated with

a platinum ceroxide layer.

Oxidation of carbon monoxide (CO) and

hydrocarbon (HC):

• As with the oxidation catalytic converter, CO and

HC are oxidized. With high levels of CO and HC

exhaust emissions, the energy release is considerable.

The resultant jump in temperature acts directly at

the point at which high temperatures are required for

oxidizing the diesel particulates.

Oxidation of nitrogen monoxide (NO) into nitrogen

dioxide (NO2):

• NO is oxidized into NO2 at the catalytic coating.

• NO2 is a more active oxidation agent than O2 and

therefore oxidizes the diesel particulates even at low

temperatures (for example at 300 ... 450 °C). The

effect is known as the CRT (Continuously

Regenerating Trap) effect or as passive

regeneration.

Oxidation of carbon monoxide (CO) into carbon

dioxide (CO2):

• Another operative mechanism is the oxidation of the

CO, which is produced at low regeneration

temperatures during the oxidation of diesel

particulates, into CO2. The combustion of diesel

particulates is improved by the localized generation

of heat.

At temperatures between 300 °C and 450 °C (attained

largely outside of cities) a passive regeneration of the

diesel particulate filter therefore takes place

continuously. It is not necessary for the engine

management to intervene.

Active regeneration

For situations when the vehicle is frequently operated

on short journeys, an active regeneration must be

initiated at certain intervals.

The PCM detects the engine's operating data and

initiates the active regeneration after evaluating the data

from the diesel particulate filter differential pressure

sensor.


Coated diesel particulate filterLesson 2 – Delphi-Common RailSystem

An attempt is then made by the engine management

system to attain the necessary temperature of

approximately 600 °C for combusting the trapped diesel

particulates. The following measures are taken to

achieve this:

• a post-injection close to the main injection,

• increasing the injected fuel quantity,

• retarded main injection,

• restricting the intake air via an intake manifold flap,

• a second post-injection at a distance from the main

injection (if necessary).

Note: The measures listed above are not all active

always. The timing map decides, depending on the

operating conditions, which measures have to be taken

to increase the temperature.

During active regeneration, the EGR system is

deactivated.

The active regeneration process can last up to 20

minutes.

Notes on the oil change interval

With frequent journeys in the lower part load range, the

maximum number of existing measures must usually

be taken to attain the exhaust gas temperature necessary

for an active regeneration.

The intervals between the individual regeneration

processes are then also shorter, so that the maximum

number of available measures have to be taken more

often.

With the maximum number of available measures, the

advanced as well as the retarded post-injection is

frequently used.

The post-injections, however, result in a greatly

increased dilution of the engine oil. In extreme cases

this means that the engine lubrication is no longer

adequately guaranteed.

In order to detect excessively diluted engine oil, an oil

quality calculation strategy has been implemented in

the PCM software.

This strategy calculates the oil quality, taking into

consideration the engine operating conditions and the

measures for increasing the exhaust gas temperature

during the regeneration processes.

E71711

If the strategy determines a proportion of fuel of more

than 7 % in the engine oil, a corresponding warning

lamp in the instrument cluster is activated.

This warning lamp signals to the driver that an oil

change must be carried out ahead of schedule.

After the oil change, the parameters for the oil quality

calculation strategy must be reset (see also the

instructions in the current Service Literature).




Emission control components

E70243

1

3

4

5

6

7 8

9

10

2


sensor1


sensor2

Diesel particulate filter differential pressure

sensor3

MAP sensor4

Intake manifold flap position sensor5

PCM6

CAN7

DLC8


Fuel injector10


The coated diesel particulate filter is built in the vehicle

for life. It therefore has no maintenance intervals.

However, if it is necessary to replace the diesel

particulate filter, the instructions in the current Service

Literature must be followed without fail.

Before replacing the PCM or before loading a new

software and after replacing the diesel particulate filter

differential pressure sensor, always read the instructions




Exhaust gas temperature sensors

E48497

Function

The exhaust gas temperature required for burning off

the diesel particulates of at least 550 ... 600 °C is

detected by the exhaust gas temperature sensors and

transmitted to the PCM.

The exhaust gas temperature input parameters are used

for calculation purposes by the PCM, which also takes

other parameters into account.

Depending on the exhaust gas temperature calculated,

the PCM decides whether or not the regeneration process

can be initiated.

Effects of faults

In the case of a fault at one of the two exhaust gas

temperature sensors, the value of the other exhaust gas

temperature sensor is used by the PCM and a substitute

value is calculated.

Diagnosis



open control loop.

• The logical rise/fall rate of the signal, whereby

intermittent faults are detected (e.g. loose connector

contacts),

• for plausibility,

Components significant for emissions (vehicles with

EOBD):


Diesel particulate filter differentialpressure sensor

NOTE: After replacing the diesel particulate filter

differential pressure sensor it is necessary to reset the

parameters for the diesel particulate filter differential

pressure sensor. In this regard, always refer to the

instructions in the current Service Literature.

E48494

Function

The diesel particulate filter differential pressure sensor

measures the current pressure differential upstream and

downstream of the diesel particulate filter in the exhaust

gas stream.




E54234


Pipe connections – diesel particulate filter

differential pressure sensor2


For this purpose, there is a pipe connection upstream

and downstream of the particulate filter.

The readings are converted by the diesel particulate

filter differential pressure sensor into a voltage signal

and transmitted to the PCM.

The soot particles and ash collected in the diesel

particulate filter result in a pressure change of the

exhaust gas upstream and downstream of the diesel

particulate filter. The altered pressure value owing to

the ash/soot load is used by the PCM as an input

parameter for determining soot and ash load.

Furthermore, a defective diesel particulate filter and the

absence of a diesel particulate filter are detected via the

diesel particulate filter differential pressure sensor.

Effects of faults

If the sensor is defective the PCM calculates the timing

of the next regeneration.

Overloaded or blocked diesel particulate filter:

• From the engine's operating conditions and from the

input parameter of the diesel particulate filter

differential pressure sensor, the PCM continuously

calculates the load status of the diesel particulate

filter.

• With an increasing ash/soot load, the engine torque

is also reduced continuously. However, this is not

noticeable by the driver. With an overloaded diesel

particulate filter there is therefore no further

intervention carried out by the PCM.

• With a blocked diesel particulate filter , only the

glow plug warning indicator/fault lamp as well as

the MIL are set.

Diagnosis



open control loop.

• the measured sensor values for plausibility

(comparison with the map data).

Via the diesel particulate filter differential pressure

sensor, the monitoring system detects:

• an overloaded/blocked diesel particulate filter. (The

pressure drop across the filter is too great and the

differential pressure exceeds a calibrated maximum

value.)

• a defective/missing diesel particulate filter. (The

pressure drop across the filter is too low and the

differential pressure falls below a calibrated

minimum value.)


• Diesel particulate filter differential pressure sensor:

Yes (MIL-active).

• Diesel particulate filter overloaded: No (Non MIL

active).



• Diesel particulate filter blocked: Yes (MIL-active).

• Defective/missing diesel particulate filter: Yes

(MIL-active).

Service instruction

After replacing the diesel particulate filter differential

pressure sensor, the adapted parameters of the sensor

must be reset in the PCM with the aid of WDS.

MAP sensor

E70244

1

2

3

MAP sensor1

Intake manifold flap vacuum unit2


Function

NOTE: In vehicles with a coated diesel particulate filter,

a MAP sensor is installed on the intake manifold flap

housing. The MAPT (Manifold Absolute Pressure And

Temperature) sensor which may possibly be installed

only fulfils the function of the IAT sensor.

During the active regeneration process the intake air is

throttled. The MAP sensor measures the intake manifold

pressure directly downstream of the throttle valve. The

vacuum measured is used by the PCM for determining

the mass air flow during the regeneration process.

Intake manifold flap and intakemanifold flap solenoid valve

Function

A high temperature (approx. 600 °C) is needed to burn

off the diesel particulates trapped in the diesel particulate

filter. This temperature, however, is not attained in all

of the engine's operating conditions.

In the lower part load range, the intake manifold flap is

partly closed and thus assists in increasing the

temperature.

The intake manifold flap is closed by the intake

manifold flap solenoid valve via a vacuum.

Effects in the event of a faulty solenoid valve

Malfunctions usually result in the intake manifold flap

being moved into the fully open position by the return

spring.

With frequent journeys in the lower part load range, a

"non-closing" of the intake manifold flap may mean

that the active regeneration process cannot be carried

out as calculated.

The strategy of the PCM tries to balance out the

malfunctions of the intake manifold flap by increasing

the injected fuel quantity in the post-injection. However,

this results in the fuel rapidly diluting the engine oil.




Diagnosis of the solenoid valve



circuit.



Intake manifold flap position sensor

Function

The intake manifold flap position sensor detects the

exact angular position of the intake manifold flap during

the active regeneration process.

Effects of faults

The effects are similar to a failure of the intake manifold

flap solenoid valve (see relevant section in this lesson).

Diagnosis


• for short circuit to ground/battery and open control

loop,

• for plausibility (required value from the timing map

to the value actually set).

Moreover, it is checked via the position sensor with the

ignition OFF whether the intake manifold flap is

completely open.





Overview

The figure depicts the two-module system; with the single-module system the IDM is integrated in the PCM.

E47803

F

4

D

3

C 2

E

B

65

7

A

1

Fuel injection lineA

High pressure lineB

Fuel return from pump to tank/filterC

Fuel feedD

Leak-off pipeE

Fuel return to tankF

Fuel injector1

Fuel rail (common rail)2

High pressure pump3

Fuel filter4



Fuel System

Fuel tank5

IDM *6

EEC V-PCM *7

On newer systems these are combined into one

control unit.*

General

Function

The fuel is drawn from the fuel tank via the fuel filter

by means of the transfer pump integrated in the high

pressure pump.

The high-pressure pump compresses the fuel and forces

it into the fuel rail.

The fuel pressure required for any given situation is

available for the fuel injectors for each injection process.

Leak-off oil from the fuel injectors and/or returning fuel

from the high pressure pump are fed back into the fuel

tank.

Possible causes of defects in fuel pipes and fueltank

Fuel lines may be blocked due to foreign bodies or

bending.

In addition, blocked parts and lines of the low-pressure

system can cause air to enter the low-pressure system

on account of the increased vacuum in the system.

Air can also enter the low pressure system through loose

or leaking pipe connections.

Faulty valves or pipes in the tank venting system can

impair the flow of fuel through the low-pressure system.

Effects in case of faults (low pressure systemcontains air or is blocked)

Poor engine starting when warm or cold

Irregular idling

Engine does not start.

Engine starts, but cuts out again immediately afterwards.

Engine has insufficient power.

Note: At a certain residual fuel amount, the PCM causes

the engine to judder. The intention is to draw the driver's

attention to the fact that the vehicle must urgently be

refueled.

Note for vehicles with EOBD: If the system causes the

engine to judder because the fuel tank is empty, the

EOBD is deactivated during this phase. This prevents

apparent faults from being displayed.


Fuel SystemLesson 2 – Delphi-Common RailSystem

Fuel filter

Function

E47818

7

12

36

4

7

5

6

Connection - return pipe1

Connection - feed pipe (from tank)2

Connection - feed pipe (to the high-pressure

pump) *3

Filter element4

Water drain screw5

Bi-metal6

Ball valve7

Feed pipe connections - in this diagram, shown

directly behind one another.*

The common rail injection system has a fuel filter which

is matched to the specific requirements of the system.

The main new feature here is the fuel pre-heating

function.

A temperature-dependent control valve is incorporated

in the fuel return line in the fuel filter.

The control valve is a bi-metal-controlled ball valve.

By heating the bi-metal, the ball valve is opened

continuously.

At a temperature of < 0 °C the return flow rate to the

filter is approximately 55 to a max. of 65 l/h. At a

temperature of > 50 °C, the return flow rate to the filter

is less than 5 l/h.

This type of fuel recirculation ensures that no

back-pressure is generated in the fuel return system.

Draining the fuel filter

The fuel filter must be drained regularly at the prescribed

maintenance intervals.

To drain the filter, loosen the drain screw and allow the

fluid to escape until pure diesel fuel appears (use a hose

and container to collect the fluid).

Note (depending on vehicle): Because access to the

drain screw is restricted, it is first necessary to remove

the fuel filter - refer to the current Service Literature.

Depending on the vehicle, the generator may also be

located below the fuel filter; as a result, there is an

increased risk of fire caused by fuel draining out of the

drain screw.

Possible causes of faults

Fuel filter may be blocked by dirt. Air may also enter

the low-pressure system as a result of leaks in the fuel

filter.

Effects of faults


Irregular idling




Fuel System

Engine starts, but cuts out again immediately afterwards. Engine has insufficient power.

Overview – high-pressure system

E47804

2

14 1

3

4

5

6

7

8

9

1011

12

13

15

Rail-type fuel injection supply manifold1

Spherical fuel injection supply manifold2

Fuel injection line3

Fuel injector4

Connection – leak-off pipe5

Electrical connection – solenoid valve6

High pressure line7

Fuel temperature sensor8




Protective plate for venturi10


Fuel supply line (from tank)12

Fuel return line (to tank)13

Fuel return line (to high-pressure pump)14


High pressure pump

Overview

E47805

2

1

3 4 5 6

7

89

10

Drive shaft1

Transfer pump (vane-type pump)2

Cam ring3

Feed bore4


Venturi in fuel return6


High pressure connection to the fuel rail8

High-pressure channel9




Fuel System

Fuel is delivered by a transfer pump (vane type pump)

incorporated into the high-pressure pump; the transfer

pump is driven by the drive shaft.

From the transfer pump, the fuel is sent via a feed bore

to the high-pressure chamber.

In the feed bore, between the transfer pump and the

high-pressure chamber, is the fuel metering valve. The

fuel metering valve is actuated electromagnetically by

the IDM and thereby regulates the cross-section of the

feed bore and thus the quantity of fuel destined for the

high-pressure chamber.

Flow of fuel through the high-pressure pump

E47806

1

7

2 3 4

5

6

Pressure control valve1

Return bore2

Feed bore - high-pressure chamber3

Leak-off fuel - fuel injectors4

Fuel return to fuel tank5

High pressure channel to fuel rail6

Fuel feed to the transfer pump7



The low pressure fuel return has the following functions:

• Cools and lubricates the high-pressure pump by the

internal return flow of the fuel, at low pressure, to

the fuel tank,

• recirculates the leak-off fuel from the fuel injectors

to the fuel tank.

When accelerating, fuel is delivered, unrestricted, to the

high-pressure chamber. In addition, a proportion of the

fuel is used to cool and lubricate the pump and flows

through a calibrated return bore and then through the

venturi back to the fuel tank.

The venturi in the fuel return works by the principle of

a suction jet pump and produces a slight partial vacuum

in the leak-off pipes, allowing the leaking oil to drain

off optimally.

E47807

1

6

2 3 4

5

Pressure control valve1

Fuel injector fuel return bore2

Feed bore - high-pressure chamber3

Leak-off fuel - fuel injectors4


Fuel feed to the transfer pump6

When decelerating, the feed to the high-pressure

chamber is closed by the fuel metering valve. As a

result, the pressure in the feed bore rises.

When a specific maximum pressure has been reached,

the pressure control valve, which is connected with the

transfer pump via a bore, opens.

The some of the excess fuel flows back to the intake

side of the transfer pump and via the venturi in the fuel

return back to the fuel tank.



Fuel System

High-pressure chamber

E47808

1

6 4

2

3

5

Inlet valve1

Cam ring2

Roller with roller support3


Outlet valve5

Pump plunger6

The storage pressure required for the fuel rail is

generated in the high pressure chamber of the high

pressure pump.

The system uses the radial piston method of operation

and consists of one inlet and one outlet valve, both of

which are fitted with a non-return valve, two pump

plungers with rollers and roller supports and a cam ring.

The cam ring forms part of the drive shaft.

The rotational movement of the drive shaft causes the

cam ring to rotate as a result of which the pump plungers

are moved backwards and forwards to the centre of the

pump.

High-pressure chamber filling

If the transfer pressure exceeds the internal pressure of

the high-pressure chamber, the inlet valve opens. Fuel

flows into the high-pressure chamber and pushes the

pump plungers via the rollers and roller supports

outwards against the cam track of the cam ring (cams

run along the rollers of the pump plungers).

The outlet valve remains closed because the pressure

in the high pressure channel, which is behind it, is

higher.

Generation of high pressure in the high pressurechamber

E47809

1

47

6

2

3

5

Inlet valve1

Cam ring2

Roller with roller support3


Outlet valve5

To the high pressure channel/high pressure

connection6

Pump plunger7



If a cam now starts to run along the roller support of the

pump plunger, the plungers moves to the centre of the

high-pressure chamber. As this occurs, the delivery

pressure of the pump plungers exceeds the transfer

pressure and the inlet valve is closed.

As soon as the pressure in the high pressure chamber

exceeds the pressure in the high pressure channel, the

outlet valve opens and fuel is supplied to the fuel rail

through the high pressure connection.

The delivery phase lasts until the apex of the cam has

reached the roller of the roller support and the pump

plungers have covered the maximum delivery path.

At this moment the pressure in the high pressure

chamber drops below that in the high pressure channel.

The higher pressure in the high-pressure channel closes

the outlet valve again and the fuel delivery phase ends.

The amount of fuel delivered depends on the

cross-section of the opening of the fuel metering valve.

Fuel rail (common rail)

E47810

1

2

3

3

4 3

3

42

B

A

Fuel fuel injection supply manifold (rail type)A

Fuel fuel injection supply manifold (spherical

type)B


Fuel rail2

Line connection (to the fuel injector)3

Line connection (from the high-pressure pump)4



Fuel System

Structure and task

The fuel rail is made of forged steel.

Depending on the engine design and availability of

space, a fuel rail can be long or spherical.

The fuel rail performs the following functions:

• stores fuel under high pressure and

• minimizes pressure fluctuations.

Pressure fluctuations can arise in the high pressure fuel

system caused by movements in the high pressure

chamber of the high pressure pump when operating and

by the opening and closing of the solenoid valves at the

fuel injectors.

The fuel rail is designed in such a way that its volume

is sufficient, on the one hand, to minimize pressure

fluctuations.

On the other hand, the volume in the fuel rail is small

enough to build up the required fuel pressure time for

a quick start in the shortest possible.

Function

The fuel supplied by the high pressure pump passes

through a high pressure line to the high pressure

accumulator. The fuel is then sent to the individual fuel

injectors via the four injector tubes which are all the

same length.

When fuel is taken from the fuel rail for an injection

process, the pressure in the fuel rail is kept almost

constant.

The pressure sensor on the fuel rail informs the

IDM/PCM about the current fuel pressure in the fuel

rail.


So that the engine management system can determine

the injected fuel quantity precisely, as a function of

current fuel pressure in the fuel rail, a fuel pressure

sensor is located on this fuel rail (see lesson 3).

Excess pressure safety valve

E47811

1

2

3

4

High-pressure connection1

High-pressure channel2

Ball valve3

Valve spring4

Inside the high-pressure pump, just in front of the

high-pressure connection is an excess pressure safety

valve incorporated into the high-pressure channel.

If there is a malfunction in the system, this is an

additional safety feature to prevent the fuel pressure

from getting too high.

If a specific maximum permissible fuel pressure is

exceeded, the valve opens against spring force and the

fuel can escape into the high-pressure pump's inner

chamber.



High-pressure fuel lines and leak-offpipes

High-pressure fuel supply lines

E47812

NOTE: The bending radii are exactly matched to the

system and must not be changed.

NOTE: After undoing one or more high-pressure fuel

line(s), it/they must be replaced. Reason: The reason

for this is that leaks can occur when re-tightening, due

to distortion of the connections of the old lines.

The high pressure fuel lines connect the high-pressure

pump to the fuel rail and the fuel rail to the individual

fuel injectors.

Leak-off pipes

Due to the operating principle of the fuel injectors work

(see section "Fuel injectors"), some of the fuel is drained

from the fuel injectors as leak-off fuel and led into the

fuel return system.

A faulty fuel injector (leaking at the solenoid valve) can

be detected by measuring the quantity of leak-off fuel

from all the fuel injectors over a specific period of time,

using special collectors (special tool).

If the quantity of leak-off fuel differs for one (or more)

fuel injector(s) (see current Service Literature), this

indicates a leak in the fuel injector.

A detailed description can be found in the section "Fuel

pressure outside the range" in Lesson 3).

Fuel injectors

Task and function

Fuel injectors on the 2.0L Duratorq-TDCi

E47813

2

1

4 3

A

B

C

Solenoid valveA

Hydraulic servo systemB

Fuel injector nozzleC

Fuel injector1

Clip for the leak-off pipe2

Leak-off pipe3

Electrical connection - solenoid valve4

The start of injection and the injected fuel quantity are

adjusted by means of the electrically-actuated fuel

injectors.



Fuel System

The fuel injectors are divided into different function

blocks:

• Fuel injector nozzle,

• Hydraulic servo system,

• Solenoid valve.

E47815

2

3

4

5

6

7

1

12

11

10

9

8

Upper inlet restriction - control chamber1

Solenoid valve2

Solenoid valve spring3

Valve needle4

Drain bore5

Drain restriction - control chamber6

Control chamber7

Nozzle openings8

Injector needle9

Nozzle prechamber10

Inlet restriction - nozzle prechamber11

Lower inlet restriction - control chamber12

Solenoid valve-controlled fuel injectors have the task

of regulating the start of injection and the injection

quantity by the stipulations of the IDM.

An extremely fast switching time (approximately

0.3 ms) is achieved due to the fact that the movable

masses of the control valves are low. As a result, the

system is able to respond quickly to changes in operating

conditions.

Fuel injector closed

The fuel is fed under pressure from the fuel rail via the

fuel feed to the nozzle prechamber and into the control

chamber.

The solenoid valve is not energized and the valve needle

therefore blocks the fuel return. In this state, the same

level of pressure exists in both the nozzle prechamber

and the control chamber (pressure equilibrium).

Because the nozzle spring is also acting on the injector

needle in the control chamber, the injector needle

remains closed (hydraulic pressure + spring force).

Fuel injector beginning to open

The solenoid valve is supplied with the pick-up current

by the IDM and the valve needle opens the fuel return.

Because of the opening of the needle valve, the pressure

in the control chamber can dissipate through the control

chamber drain restriction.

The pressure reduction is delayed accordingly by the

control chamber drain restriction so that the fuel injector

nozzle remains closed.



E47816

1

2

3

4

5

6

7

1

2

3

9

4

A B

8

Fuel injector closedA

Fuel injector beginning to openB

Solenoid valve1

Fuel return2

Valve needle3

Control chamber4

Nozzle spring5

Injector needle6

Nozzle prechamber7

Fuel feed8

Drain restriction - control chamber9

Fuel injector completely opened (fuel injection)

The high pick-up current of 12 A is reduced to a holding

current of 6 A. The fuel return is still open.

As soon as the pressure in the nozzle prechamber is

higher than that in the control chamber (hydraulic

pressure plus spring pressure is less than the pressure

in the nozzle prechamber), the injector needle begins to

open (start of injection).

Fuel injection ends

After a period determined by the IDM, the power supply

to the solenoid valve is interrupted and the valve needle

closes off the fuel return via solenoid valve spring force.

Pressure is built up again in the control chamber via the

upper and lower inlet restrictions.



Fuel System

At the same time the inlet restrictions of the nozzle

prechamber prevent a sudden back pressure of fuel in

the nozzle prechamber. This rapidly causes a higher

pressure level in the control chamber and the injector

needle closes the fuel injector nozzle.

E47817

C D

7

8

9

5

1

6

2

3

1

4 4

2

3

InjectionC

Fuel injection endsD

Fuel return1

Control chamber2

Injector needle3

Nozzle prechamber4

Solenoid valve5

Valve needle6

Inlet restriction - nozzle prechamber7

Lower inlet restriction - control chamber8

Upper inlet restriction - control chamber9



Identification number (fuel injector correctionfactor)

Example of an identification number on the fuel injector

of the Ford Mondeo

E47814

Inside the hydraulic servo system there are various

restrictions with extremely small diameters which have

specific manufacturing tolerances.

These manufacturing tolerances are given as part of an

identification number which is located on the outside

of the fuel injector.

To ensure optimum fuel metering, the IDM must be

informed without fail of a change of fuel injector.

This is achieved by entering the identification number

into the IDM using the WDS, ensuring in the process

that the number is paired with the corresponding

cylinder.

Note: If the identification numbers are not entered

properly with WDS, the following faults can occur:

• Increased black smoke emissions,

• Irregular idling,

• Increased combustion noise.

Effects of faulty fuel injector(s) (mechanicalfaults)

Increased black smoke production

Fuel injector leaks

Increased combustion noise as a result of coked injector

needles

Irregular idling



Fuel System


1. What is understood by the "single-module system"?

a. A single-module system is a compact injection system such as the common rail injection system.

b. The ABS module and the PCM are located in a shared housing.

c. All control units in the vehicle are combined into one control unit.

d. The IDM is integrated into the PCM.

2. What happens when the CMP signal is not detected during starting?

a. The injected fuel quantity is reduced so that the engine is very difficult to start.

b. The injected fuel quantity is set to 0 and the engine does not start.

c. The engine starts, but only runs in restricted limited operation mode.

d. Although the engine starts, it frequently misfires.

3. Which statement regarding the system with coated diesel particulate filter is correct?

a. During passive regeneration, an intensive intervention is performed by the engine management to increase

the exhaust gas temperature.

b. During active regeneration no further interventions by the engine management are required.

c. During active regeneration, an intervention is performed by the engine management to increase the exhaust

gas temperature.

d. Passive regeneration takes place continuously at exhaust gas temperatures up to 350 °C.

4. What is the significance of the identification number on the injector?

a. It provides information about the date and location of manufacture.

b. This number is used by the IDM or PCM via WDS as a correction factor for the injector.

c. It indicates for which vehicle the injector was manufactured (Focus, Mondeo, Transit).

d. Not important - contains only factory data.


Test questionsLesson 2 – Delphi-Common RailSystem


• name all the engine management components.





• specify the components of the diesel particulate filter system.


• name and describe the modifications to the air intake system.

• specify and explain the components of the fuel additive system.

• explain the electrical/electronic components of the diesel particulate filter system.




• explain what factors must be taken into consideration when replacing certain components.


ObjectivesLesson 3 – Bosch-Common RailSystem

Overview

E70768

1

2

5

6

7

8

9

10

11

13

15

19 20

16 17 18

14

12

31

30

29

28

27

26

25

242322

3

4

21


Lesson 3 – Bosch-Common RailSystem

MAP sensor1


Combined IAT sensor and MAF sensor3

IAT sensor (only with diesel particulate filter

system)4


ECT sensor6

CMP sensor7

CKP sensor8

Stoplamp switch9

APP sensor10

BPP switch11

DC motor for the EGR valve with an integrated

position sensor12

CPP switch13

Oil pressure switch14

Generator (input signal)15

Start inhibit relay16

Ignition lock17

Battery18

DC motor for intake manifold flap with an

integrated position sensor (vehicles with a diesel

particulate filter)

19

DC motor for intercooler bypass flap with

integrated position sensor (emission standard IV)20

PCM with an integrated BARO sensor21

CAN22

DLC23

Fuel injectors24


Sheathed-type glow plug control module26


Cooling fan control and A/C compressor28

PCM relay29

Generator (output signal)30

Gateway (e.g. instrument cluster or GEM

(Generic Electronic Module))31

Characteristics

The following components originate from the Bosch

company:

• High-pressure pump (with fuel metering valve),

• Fuel injectors,

• PCM.


required and conveys it into the fuel rail. The fuel

metering is carried out through electrical actuation of

the solenoid valve-controlled fuel injectors by the

PCM.


Fuel injectors

An 8-digit identification number is engraved on every




of WDS.








MAF

After replacing a MAF sensor it may be necessary to

perform a parameter reset with the aid of WDS. In this

regard, refer to the instructions in the current Service

Literature.

Electric EGR valve

After replacing the electric EGR valve a parameter reset

must be performed via WDS in the PCM.


On replacing the PCM following a PCM crash





After replacing the diesel particulate filter a parameter

reset must be performed via WDS in the PCM.

In some versions it may be necessary after replacing

the diesel particulate filter differential pressure

sensor or the PCM to reset the parameters for the diesel

particulate filter differential pressure sensor. In this

regard, always refer to the instructions in the current

Service Literature.

PCM

Function

E43243

The Bosch PCM is the main component of the engine

management system. It receives the electrical signals

from the sensors and set-point transmitters, evaluates

them and calculates the actuation signals for the

actuators (for example fuel injectors, boost pressure

control solenoid valve, EGR valve, etc.) from them.




Note: The further "functioning" is similar to that for the

Delphi common rail system (see relevant section in

"Lesson 2").

Diagnosis

In the course of the diagnosis, the PCM is monitored

for correct operation. Malfunctions are therefore

detected and indicated using a relevant diagnostic

trouble code entry.

In addition to this, the following are also monitored:

• Power supply voltage monitoring,

• EEPROM monitoring.



In the case of power supply voltage monitoring

comparators compare the individual sensor supply

voltages calibrated in PCM to check if they are within

limits. There are three power supply voltage channels

in total in the PCM.

Faults in the power supply voltage indicated by an

engine system fault warning lamp are therefore non

MIL active.

Possible diagnostic trouble codes: P0642, P0643,

P0652, P0653, P0698, P0699

The engine adjustment data and freeze frame data are

stored in the EEPROM.

The freeze frame data forms part of the EOBD. Incorrect

entries are detected appropriately and indicated by a

diagnostic trouble code, but are non MIL active.


P1676.

Glow plug control

E51120

1

2

3

4 6 8

75



Battery junction box1


Sheathed-type glow plug 13




PCM7

Instrument cluster with glow plug warning

indicator8

Function

The glow plug system of the Siemens common rail

system is designed so that each sheathed-type glow

plug is actuated separately.

For this purpose, the PCM transmits information on

glow duration to the glow plug control module. The

glow plug control module then actuates the

sheathed-type glow plugs.

In the case of a faulty sheathed-type glow plug (or when

short circuit/open control loop occurs in a glow plug)

this is detected by the glow plug control module and


In this way, a fault in the electrical circuit of a glow

plug can be accurately pinpointed.

In order to calculate the glow time precisely, the PCM

requires the following input signals:

• ECT,

• Engine speed (CKP signal),

• BARO.

Generally, activation/deactivation of the sheathed-type

glow plugs during the pre- and post-heating phases

depends on the relevant ECT and BARO.

The relevant calibration data is stored as map data in

the PCM and in addition to the ECT, BARO and engine

speed, the injected fuel quantity (engine load condition)

is also significant for the post heating process.

The on-time of the glow plug warning indicator is

determined by the PCM. However, it does not provide

any indication of the actual actuation times of the

sheathed-type glow plugs. At low temperatures, the

on-time of the glow plug warning indicator is shorter

than the actuation time of the sheathed-type glow plugs.

The signal for the glow plug warning indicator is

transmitted by PCM via the CAN bus to the gateway

(instrument cluster or GEM) where the glow plug

warning indicator is activated.

Preheating

The PCM receives the corresponding temperature signal

from the ECT sensor.

The length of the preheating period depends on the

temperature signal (low temperature = longer preheating

period).

The driver is informed of preheating by the lit glow plug

warning indicator in the instrument cluster. The

preheating times become longer as the coolant

temperature falls.

The BARO also has an influence on activation and

deactivation of the sheathed-type glow plugs in the event

of large altitude differences.

Example:

• ECT = 60°C, BARO = 0.95 bar:

– Sheathed-type glow plug deactivated,

• ECT = 60°C, BARO < 0.90 bar:

– Sheathed-type glow plug = activated



Post heating

Preheating is followed by the post heating phase once

the engine has started. The post heating phase depends

upon how the vehicle is driven.

In addition to ECT, BARO and engine speed, the

injected fuel quantity is significant in this context. If,

for instance, the injected fuel quantity is 7 mg per piston

stroke and the coolant temperature is below 20 °C, post

heating is performed at engine speeds between 1100

and 3500 rpm.

In the case of greater injection quantities and

considerably lower engine temperatures, the post heating

phase is also activated depending on the engine speed.

At 14 mg per piston stroke and an ECT of below 0 °C,

for example, post heating is performed at engine speeds

between 1100 and 1500 rpm.

Effects of fault (engine cold)

Longer starting process.

Loud combustion noise after starting.

Rough engine running.

Diagnosis

Glow plug control monitoring is divided into three

monitoring steps:

• checking for short circuit and open control loop,

• plausibility check for a sticking, open glow plug

relay,

• plausibility check for a sticking, closed glow plug

relay

Checks for short circuit and open control loop, as well

as the plausibility checks are activated after ignition

ON, except if the system detects a defective glow plug

control output stage or the battery voltage is excessively

low.

If the system detects a sticking glow plug control relay,

engine power output is reduced and the engine system

fault warning lamp is switched on.

Faults in the glow plug control do not have any effect

on the EOBD limits. It is a non MIL-relevant system.


P138A, P138B, P1391, P1392, P1395.



CKP sensor

Function

CKP sensor installation position

E51121

2

1

Crankshaft vibration damper1

CKP sensor2

The CKP signal is a prerequisite for the calculation of

injected quantity and injection timing.

The CKP sensor works according to the Hall principle

and scans a magnetic disc on the crankshaft timing

pulley.

The CKP signal is used:

• to determine engine speed,

• to synchronize with the CMP signal,

• to determine the crankshaft position.

Effects of faults

If there is no signal, the engine cannot be started or cuts

out.

Diagnosis

The CKP sensor is checked for short circuit and open

control loop.

Moreover, a plausibility check is implemented, which

monitors synchronization with the CMP signal.

Since the engine cuts out or cannot be started in the

event of a fault, the CKP sensor has no effect on exhaust

emissions. No additional monitoring measures relevant

for EOBD have been implemented.

Therefore, this is a non MIL active component.

In the event of a fault, the engine system fault warning

lamp is actuated.


P0339.

CMP sensor

Function

E51123

The CMP signal is required by the PCM to activate the

individual fuel injectors according to the injection

sequence. The CMP sensor works on the Hall principle.

The square-wave signal is used to identify cylinder 1,

in conjunction with the CKP signal.

Effects of faults

When the engine is started, the synchronization between

the CKP signal and the CMP signal takes place in the

PCM.

If synchronization cannot be completed successfully,

no injection enable signal is sent by the PCM, and the

engine does not start.



Sensors

If synchronization is successfully completed, the CMP

signal is of no further consequence. This means that any

potential CMP signal loss while the engine is running

has no effect.

Diagnosis

From the description above it can be concluded that the

CMP sensor has no effect on exhaust emissions in the

event of a fault, as the engine cuts out or cannot be

started.


In the event of a fault, the engine system fault warning

lamp is actuated.


P0344.

MAP sensor

Function

The illustration shows the MAP sensor in a vehicle with

a diesel particulate filter system

E51124

The MAP sensor is located in the air intake tract

downstream of the intercooler. The MAP sensor has the

following functions:

• Measuring the current boost pressure,

• Calculating the air density for adapting the injected

quantity and the injection timing,

• Calculating the turbocharger outlet temperature.

Effects of faults

In the event of a fault, the guide vanes of the variable

geometry turbocharger are opened completely. Boost

pressure is minimized. Furthermore, the EGR system

is deactivated and the injected fuel quantity is

appreciably reduced (reduced engine power output).

Diagnosis

Within the framework of EOBD, the proper functioning

of the MAP sensor is of great importance.

Malfunctions lead to significantly increased emissions,

as the EGR system is switched off and the boost pressure

reduced to a minimum. For this reason, it is a MIL

active component.

The monitoring system continuously checks whether

the values output by the MAP sensor are within limits.

Furthermore, a plausibility check is performed in the

monitoring system. It is however only performed if the

limit check was completed without any faults.

The plausibility check takes place at a set low engine

speed. Here, the PCM compares the current pressure at

the MAP sensor with the pressure measured at the

BARO sensor for a defined period of time.

If the system detects an excessive deviation from the

target map data, it concludes immediately that the MAP

sensor is defective and changes over to a substitute

parameter.


SensorsLesson 3 – Bosch-Common RailSystem


P0237, P0238.

BARO sensor

Function

The BARO sensor is located in the PCM and measures

the ambient air pressure.

With increasing geographical altitude (for example when

driving up a hill) the air density and therefore the air

resistance decreases. This has an effect on the engine

cylinder charge and the turbocharger speed.

To avoid damage to the turbocharger and increased

formation of black smoke, a BARO sensor is integrated

into the PCM. It is used for making appropriate

adaptations in the fuel metering and in the exhaust gas

recirculation.

Effects of faults

In the event of a fault, the signal from the MAP sensor

is used to determine the ambient air pressure.

If both sensors (BARO und MAP) are defective, the

PCM uses a substitute value. In this case, the injected

fuel quantity and therefore engine performance is

significantly reduced.

Diagnosis

The PCM continuously checks the BARO sensor for

short circuits (to ground and positive) and for open

control loop.

The signal from the BARO sensor is checked for

plausibility by performing a comparison test with the

MAP signal in a specific low load range.

Since the BARO sensor influences the EGR system,

this is a MIL active component.


P2229.

ECT sensor

Function

E51427

The ECT sensor is located in the small coolant circuit

of the engine and measures the coolant temperature.

This sensor is a temperature-sensitive resistance element

with an NTC (Negative Temperature Coefficient).

The voltage value supplied by the ECT sensor is

assigned to a corresponding temperature value by the

PCM.

The ECT is used for the following calculations:

• Idle speed

• Injection timing

• Injected fuel quantity

• EGR quantity



warning indicator

• Fan control

Effects of faults

When a sensor malfunctions or overheating of the engine

occurs, the "engine overheating" fail-safe mode is

enabled.



Sensors

In this mode, engine power is reduced by injecting less

fuel. If the engine temperature still continues to increase,

the engine power output is decreased further still,

depending on the vehicle version.

In fail-safe mode the cooling fans run at maximum

power.

Diagnosis

As described previously, the engine coolant temperature

is used in a variety of calculations and thus has an

important effect on exhaust emissions.

In addition, the engine coolant temperature is required

to define the warm-up cycle.

Therefore, this is a MIL active component.

The monitoring system continuously checks if the values

output by the ECT sensor are within limits.

The PCM interprets deviations from limit values as an

open control loop or a short circuit (to ground and to

battery).

The ECT sensor is checked for plausibility by the fact

that a specific calibrated temperature increase has to

occur within a set period of time after the engine starts.

The plausibility check is only performed if the limit

check was completed without any faults.

Plausibility check

E51125

T

1

4

3

2

t

5

Engine coolant temperatureT

Assumed engine coolant temperatureT1

Minimum temperatureT2

Minimum temperature not reachedT3

Timet

Timer1

Implausible temperature increase2

Expected minimum temperature increase3

Plausible temperature increase4

Timer cancellation5

Performing the plausibility check:

• After the engine has been started, the PCM assumes

an engine coolant temperature value.

• If the engine speed and the injected quantity exceed

a calibrated value due to the temperature value

assumption, a timer is started in the PCM.

• During timing, the PCM checks whether a sufficient

temperature increase and a calibrated minimum

temperature are reached.



• If this is not reached after timeout, an implausible

value is assumed and a DTC is stored.

• If, however, a sufficient temperature increase and a

calibrated minimum temperature are reached during

timing, the plausibility check is deemed to have been

successful and is stopped.

In the event of a fault, the engine management system

reverts to a substitute value and the engine runs at

reduced power output. In this case, the cooling fans are

switched to run at maximum power.


P0117, P0118.

Combined IAT sensor and MAF sensor

Function

E43242

1

MAF sensor1

The MAF sensor measures the air mass drawn into the

engine. The MAF signal has an effect on the injected

quantity and the injection timing.

Furthermore, the MAF signal is used to control the

exhaust gas recirculation (closed control loop).

There is an IAT sensor integrated into the MAF sensor.

The IAT is used to correct the MAF signal. This ensures

a more precise measurement of the mass air flow. The

EGR rate can be metered with greater precision. This

has a positive effect on the exhaust emissions.

Furthermore, the IAT signal is used to calculate the

turbocharger outlet temperature. The established value

is used as a coefficient of correction when calculating

the air density through the MAP sensor.

Effects of faults

If the signal from the MAF sensor fails, the EGR system

is deactivated.

To calculate the mass air flow when the signal fails a

substitute value is used. The substitute value for the

mass air flow for each cylinder is calculated by the PCM

from the engine speed.

Diagnosis


• if the values output by the MAF sensor are within

limits.

• the sensor for short circuit to ground/battery,

• for intermittent faults (for example loose contact),

• the sensor signals for plausibility.

Since the EGR system is deactivated in the event of a

fault, this is a MIL active component.

Possible diagnostic trouble codes:

• MAF sensor: P0100, P0101, P0102, P0103.

• IAT sensor in the MAF sensor: P0110, P0112,

P0113, P0071.



Sensors

Vehicle speed signal

Function

E51126

12

3

Wheel speed sensors1

ABS module2

PCM3

The vehicle speed signal is determined by the Bosch

common rail system via the wheel speed sensors of the

ABS.

The signal from the wheel speed sensors is transmitted

via the CAN communication bus. The PCM calculates

the vehicle speed from this.

For the calculation of the vehicle speed, the wheel

speeds of both front wheels are detected and an average

value is calculated.

If one or both front wheel speed sensors are faulty, the

signals of both rear wheel speed sensors are used and

their average is used as the vehicle speed value. If a

fault occurs to the wheel speed sensors (one or both), a

reliable vehicle speed signal can no longer be

transmitted via the CAN data bus.

The signal is used by the PCM to calculate the gear

selected and as information for the speed control which

is integrated in the PCM.

Effects of faults

increased idling speed

uncomfortable judder during gearshifts.

Diagnosis

The VSS has only minor effects on exhaust gas

emissions and does not exceed the EOBD limits.

The vehicle speed sensor signal is, however, part of the

freeze frame data and is therefore classified as MIL

active.

Possible diagnostic trouble codes: P0500, P1934.

APP

Function

For safety reasons, the APP sensor is designed as a

inductive double sensor.

E51981

In this system, the signal from APP sensor 1 is

transmitted directly as a pulse width modulated signal

to the PCM.

The APP sensor 2 signal is transmitted as an analog

signal to the instrument cluster.

In the instrument cluster the APP 2 signal is digitized,

then put onto the CAN data bus and transferred to the

PCM.



Effects of faults

If one of the two sensors of the APP sensor fails, the

engine runs at reduced power output. However, it is still

possible to reach top speed.

If the vehicle is equipped with a driver information

system, the fault message: "REDUCED

ACCELERATION" is displayed.

If the APP sensor fails completely, the engine is

regulated to a speed of up to 1200 rpm after the BPP

switch and the stop lamp switch have been actuated

once and a plausibility check has been carried out. The

vehicle can be accelerated to a maximum speed of 56

km/h.

If the vehicle is equipped with a driver information

system the error message "LIMITED MAXIMUM

SPEED" is displayed.

If the vehicle is not equipped with a driver information

system the "engine system fault" warning lamp

illuminates when a system error occurs.

Fuel temperature sensor

Function

E30972

The fuel temperature sensor is located in the fuel return

system in a T-piece above the fuel rail.

It measures the fuel temperature in the low-pressure

system.

With the help of this signal, the fuel temperature is

continuously monitored to prevent overheating of the

injection system.

The critical fuel temperature is approx. 90 °C. When

the maximum fuel temperature is approached, the fuel

pressure and injected quantity is limited accordingly.

Effects of faults

In the event of a fault, the PCM assumes a maximum

temperature value, which results in a reduction of the

engine power output.

Diagnosis

The monitoring system continuously checks if the signal

is within the limits as well as for short circuit and open

circuit.

Faults on the fuel temperature sensor have no effect on

the exhaust gas emissions and therefore do not affect

the EOBD limits.

For this reason, it is a non MIL active component.


P0183.


Function

E30973



Sensors



delivers a voltage signal to the PCM in accordance with


The fuel pressure sensor operates together with the

fuel metering valve on the high-pressure pump in a

closed-loop control circuit.




• drive the fuel metering valve on the high-pressure

pump.

Effects of faults

The fuel pressure is a critical value. If the signal should

fail, it is no longer possible to carry out a controlled

injection process.

In the event of a short circuit or open control loop the

PCM assumes a fuel pressure that is higher than the

maximum permissible pressure. In response, the injected

fuel quantity is set to 0 and the engine cuts out or cannot

be started.

The injected fuel quantity is also set to 0 if values are

implausible.

Diagnosis

The fuel pressure sensor is continuously checked during

analogue signal acquisition to establish whether the

signal is within the limits.

If the sensor voltage exceeds the upper limit, the PCM

records a "limit fault high".

If the sensor voltage in the next test cycle has fallen

below the limit range again, this is registered by the

PCM as "Sensor OK". However, if the "limit fault high"

message remains for a set time, this is interpreted as a

fault, and the engine is ultimately stopped.

The same takes place if the lower limit range is

exceeded.

The sensor is also checked for short circuits (to ground

and battery) and open control loop.

As the engine cuts out in event of a fault, a faulty fuel

pressure sensor signal has no effect on the EOBD limits.


In the case of a fault, the engine system fault warning

lamp illuminates.


P0192, P0193.



Oil pressure switch

E52848

3

1 2

PCM1

Instrument cluster2


The oil pressure in the engine's oil circuit is monitored

via the oil pressure switch.

If the oil pressure is incorrect, this is detected by the oil

pressure switch, which then transmits a signal to the

PCM.

In the PCM the signal from the oil pressure switch is

placed on the CAN communication bus and forwarded

to the instrument cluster, causing the oil pressure

warning indicator to illuminate.

There is no fault strategy implemented.

Stoplamp switch/BPP switch

Function

The signal of the stop lamp switch influences fuel

metering when the brake is applied and a gear is engaged

at idle speed.

Example: During braking, the PCM receives a signal

from the stoplamp switch which results in the fuel

quantity for idle control being reduced. This prevents

the idle control system from continuing to maintain idle

speed and counteracting the braking action.

In addition, there is a BPP switch installed. In vehicles

with a speed control system, the stoplamp switch and

the BPP switch both send the "brake applied" signal to

the PCM for safety reasons.

In addition, the signals from both switches are used to

check the APP sensor (plausibility check).

CPP switch

Function

Using the CPP switch, the PCM identifies whether the

clutch is engaged or disengaged.

The quantity of injected fuel is briefly reduced during

actuation of the clutch to avoid engine judder during

gearshifts.

The CPP switch is located on the pedal box assembly.

On vehicles with a speed control system, the CPP switch

switches off the speed control system when the clutch

is disengaged.

Effects of faults

Engine judder during gearshifts.



Switch

Fuel metering valve (CP3.2)

Function

E51238

The fuel metering valve regulates the fuel quantity

which is fed to the high-pressure chambers of the

high-pressure pump depending on the fuel pressure in

the fuel rail.

As a result, the quantity of fuel that flows back to the

fuel tank is kept to a minimum.

E51239

1 6 6

7

4

5

2

3

Coil1

Wiring harness connector connection2

Valve needle3

Valve closed4

Maximum opening cross-section5

From the transfer pump6

To the high-pressure chambers7

NOTE: The fuel metering valve is fully opened in its

de-energized state.


ActuatorsLesson 3 – Bosch-Common RailSystem

The fuel metering valve is controlled by PWM signals

from the PCM. The type of pulse width modulation is

a function of:

• Driver's requirements,

• Fuel pressure requirement,

• Engine speed.

The fuel metering valve operates together with the

fuel pressure sensor on the fuel rail in a closed

control loop.

Effects of faults

In the event of serious malfunctions, the injected

quantity is set to 0 and the engine cuts out or cannot be

started.

Malfunctions in the fuel metering valve are detected by

continually comparing the fuel pressure request

(calculated by the system) and the actual fuel pressure

(measured in the fuel rail). In the event of a deviation

from a set tolerance range, the injected quantity is set

to 0 and the engine cuts out or cannot be started.

Diagnosis

The EOBD requirement demands the detection of faults

when determining the injected fuel quantity and fuel

injection timing. These parameters have serious effects

on the exhaust gas emissions.

The determination of the fuel injection timing is

established via the crankshaft position.

The injected quantity results from the engine speed and

the opening time of the fuel injector, depending on the

fuel pressure in the fuel rail.

Monitoring of the fuel pressure is a function determined

by the interaction of the fuel metering valve (adjusting

the delivery quantity for the fuel rail) and the fuel

pressure sensor (adjusting the desired fuel pressure).

From the output shape of the pulse width modulated

signals, the monitoring system identifies (by comparing

it with the target map data) whether the actuation is

within the limits.

The Bosch diagnostic system classifies faults in the fuel

metering valve either

• as control faults (in this case the engine speed is

limited to a safe range) or

• as malfunctions (in this case the engine is switched

off by the PCM).

.

In addition, short circuits (to ground and battery) and

open circuits are monitored.

Control faults only have minor effects on exhaust gas

emissions. Consequently, this is a non MIL active

component, as the EOBD limits are not exceeded.

Malfunctions result in the engine being stopped by the

PCM; this ensures that the exhaust gas emissions are

not affected.


P0193, P0251, P0252, P0253, P0254.

Fuel metering valve (CP1H)

E70771



Actuators

NOTE: When de-energized, the fuel metering valve is

completely closed.

Additional functions as well as strategies are essentially

the same as those of the fuel metering valve of CP3.2

(see relevant section in this lesson).


Function

E51243

2

3

1

Solenoid armature1

Wiring harness connector connection2

Solenoid valve needle3



PCM.

The electrical supply of the solenoid valves occurs in

several phases:

1. Opening phase,

2. Pickup current phase,

3. Transition to holding current phase

4. Holding current phase,

5. Turn-off phase,

6. Recharge phase



E51244t

A

B

C

1 2 3 4 5 6

Solenoid valve currentA

Solenoid valve needle liftB

Injected fuel quantityC

Timet

Opening phase1

Pickup current phase2

Transition to holding current phase3

Holding current phase4

Turn-off phase5

Recharge phase6

In the opening phase the current has to increase initially

to approximately 20A with a steep edge to achieve a

low tolerance and therefore high repeatability for

calculation of the injected quantity.

This is achieved by using an amplifier voltage of up to

100 V which is generated in the PCM and stored in a

capacitor.

By applying this high voltage to the solenoid valve, the

current rises several times steeper than when battery

voltage is applied.

In the pickup current phase the solenoid valve is

supplied by battery voltage. This supports rapid opening

of the solenoid valve.

Current control limits the pickup current to

approximately 20A.

In the holding current phase the current is reduced to

approx. 12A. Unnecessary heat generation in the PCM

is prevented in this way.

When lowering the pickup current to holding current,

energy is released. It is supplied to the capacitor

(amplifier voltage storage) for recharging.



Actuators

In the turn-off phase the current is switched off to close

the solenoid valve. This releases energy which is also

supplied to the capacitor.

The recharge phase takes place between injections.

For this purpose, an unused solenoid valve is supplied

with a saw-tooth current. The current level is so low,

however, that the solenoid valve is not opened.

The energy stored in the solenoid valve is also supplied

to the capacitor so that it is fully charged for the next

opening phase.

Effects of faults


increased emissions of black smoke,


Diagnosis

The monitoring system is able to identify two types of

malfunctions via several electrical tests.

• Fuel metering fault of all fuel injectors,

• Fuel metering fault of a single fuel injector

This works by monitoring the staged power supply

(current phases) of the fuel injectors (as described

previously).

The power consumption of the solenoid valve coil (in

relation to a defined time) indicates whether the solenoid

valve is working within its tolerances.

Deviations from the tolerance range result in

uncontrollable fuel metering. This means that the

injected quantity and the injection timing cannot be

determined exactly (see Possible consequences of

faults).

In addition, the fuel injectors are checked for short

circuit and open circuit.

Fuel injector faults are MIL active if continued engine

running is permitted.

Possible diagnostic trouble codes: P0201 to P0204

(MIL active); P1201 to P1204, P1551 to P1554 (non

MIL active)

Boost pressure control solenoid valve

Function

The boost pressure control solenoid valve is supplied

with vacuum by the vacuum pump.

Pulse width modulated signals from the PCM control

this vacuum via the boost pressure control solenoid

valve.

The controlled vacuum acts upon the vacuum unit of

the turbocharger.

Effects of faults

In the event of a fault, boost pressure control is no longer

possible. Due to this, the injected fuel quantity is limited

(power output reduction) and the EGR system is

switched off.

Diagnosis

Boost pressure control operates in a closed control loop.

The adjustment of the guide vanes of the variable

geometry turbocharger is carried out via the boost

pressure control solenoid valve. The boost pressure is

controlled depending on requirements via the MAP

sensor.

Faults on the boost pressure control solenoid valve or

on the vacuum system are detected by the MAP sensor.

As the EGR system is deactivated, the NOX emissions

increase sharply. As a result, EOBD limits are exceeded.

Therefore this is a MIL active component.



EGR valve

Function

E43241

The EGR valve is fitted on the exhaust side of the engine

on the cylinder head.

The EGR valve comprises the following components:

• Servo motor,


• the EGR valve itself. E51298

M

1

3

1

2

4

PCM1

DC motor2

Servo motor3

Position sensor4

NOTE: After the EGR valve is replaced or after the

PCM is replaced/reprogrammed, the EGR valve must

be initialized by the PCM via WDS.

The servo motor acts as a DC motor that sets the

requested opening cross-section of the EGR valve.

Actuation is by means of the PCM using pulse width

modulation.

The exact position of the EGR valve is established via

the position sensor.

It is therefore a closed control loop.



Actuators

Note: Each time the engine is stopped, a cleaning mode

is activated by the PCM, whereby the EGR valve is

moved from its fully open position to a completely

closed position (by means of maximum activation of

the DC motor).

However, the longer the engine is in operation, the

greater the likelihood of residues forming on the valve

seat of the EGR valve as a result of the exhaust gases

flowing past it. These residues can cause the mechanical

closing point of the EGR valve to shift.

For this reason, the closing is re-adapted at regular

intervals. Consequently, the position sensor also retains

its precise measurement after a long period of operation.

Effects of faults

In the case of a fault, controlled exhaust gas recirculation

is no longer possible and the EGR system is switched

off. If the EGR sticks open, this is detected by the

position sensor and the PCM then reduces the quantity

of fuel injected and thus engine performance.

Diagnosis

Monitoring of the EGR servo motor is divided into three

monitoring operations:

• Monitoring of the DC motor,

• Monitoring of the position sensor,

• Monitoring of the EGR valve.

In addition, the entire EGR system (interaction between

the EGR valve, position sensor, servo motor and MAF

sensor) is monitored under certain operating conditions.

The DC motor is monitored through a simple electrical

test.

The output stage in the PCM for the DC motor is

continuously checked for short circuit and open circuit,

as well as for malfunctions that can occur due to high

temperatures.

The position sensor is monitored for the following:

• Limit monitoring: The PCM checks constantly if the

incoming signal is within the limits.

• Monitoring for short circuit and open circuit,

• Position sensor reference voltage monitoring.

The position sensor also detects when the EGR valve

is sticking in the open position. This is detected by

adaptation of the mechanical closing point. For

detection, the valve has to move a certain distance from

its fully opened state to its fully closed state. If the

expected distance is not traveled as programmed, the

position sensor detects this and interprets it as a fault.

Another control function checks whether the position

of the EGR valve is reached according to the

requirements. This monitors proper mechanical

functioning of the EGR valve.

Faults in the EGR valve have serious effects on the

exhaust gas emissions. If the level of exhaust gas is too

low, the NOX emissions increase, if it is too high, the

diesel particulate emissions increase dramatically.



P0405, P0406, P1412.

Intake manifold flap servo motor(vehicles with diesel particulate filter)

Function

E513731

2



An intake manifold flap is located in the air intake

system which has the following functions:

• Restricting the intake air for exhaust gas

recirculation,

• Closing the intake system when the engine is

stopped,

• Closing the air path via the intercooler while the

regeneration of the diesel particulate filter takes place

(see section on "Diesel particulate filter with fuel

additive system" in this lesson).

The intake manifold flap is actuated by a servo motor.

The servo motor is a DC motor that precisely controls

the requested position of the intake manifold flap

through actuation by the PCM.

In addition, there is a position sensor in the servo motor

that informs the PCM of the current position of the

intake manifold flap (closed control loop).

In order to restrict the intake air flow, the intake

manifold flap is closed by a set percentage value

depending on requirements.

This produces a specific vacuum behind the intake

manifold flap. This vacuum results in the recirculated

exhaust gases being drawn in more efficiently by the

engine via the EGR valve and therefore in a higher EGR

rate to be delivered to the cylinders.

E51375

2

2

4

1

3

5

Power supply from the battery junction box1

PCM2

DC motor3

Servo motor4

Position sensor5

When the engine is stopped, the intake manifold flap

is closed. This prevents intake air from being drawn in

and, consequently, running on (judder) of the engine.

In the case of vehicles with a diesel particulate filter

the intake air temperature has to be increased under

certain operating conditions for the regeneration process.

To achieve this, the intake air valve is closed depending

on requirements and an intercooler bypass opened

(bypass of the intercooler) – see "Lesson 4 – Engine

emission control".



Actuators

Effects of faults

The intake manifold flap is sticking in the open position:

• EGR is limited or switched off.

• When switching off the engine, increased engine

judder occurs.

The intake manifold flap is sticking in the closed

position:

• Engine does not start.

If the intake manifold flap is sticking, only limited

control of exhaust gas recirculation is possible.

Depending on the position in which it is sticking, too

much exhaust gas could be recirculated under certain

load conditions. In this case, the injected fuel quantity

and therefore the engine power output is reduced to

prevent black smoke.

Serious faults at the position sensor will result in the

EGR system being deactivated.

Diagnosis

Monitoring the intake manifold flap (by means of the

position sensor) includes the following checks:

• Limit range check,

• Plausibility check,

• Control deviations,

• Sticking intake manifold flap.

Most faults result in limited exhaust gas recirculation

or the EGR system being deactivated, which means that

the maximum exhaust emission levels are exceeded.



P0487, P0488, P2141, P2142.



Regeneration process

General

With the use of diesel particulate filters the remaining

diesel particulate matter can be reduced by more than

99%.

The storage capacity of the diesel particulate filter is

limited. This means that the diesel particulates

accumulated in the diesel particulate filter have to be

removed periodically.

This is achieved by burning off the diesel particulates

at set intervals.

A burn-off of diesel particulates takes place chemically

at a temperature of approximately 600 °C. As the

exhaust gas temperature during the approved European

driving cycle rarely exceeds 270 °C due to the low

engine load, measures have to be initiated to enable

burn-off of the diesel particulates.

These measures are:

• Sustained increase in exhaust gas temperature,

• Lowering the oxidation temperature by using a fuel

additive.

The increased exhaust gas temperature is achieved

by:

• Closing of the intake manifold flap,

• Opening the intercooler bypass (increasing the intake

air temperature by bypassing the intercooler),

• Two post-injections,

• Closing of the EGR valve,

• Actuation of the guide vanes of the turbocharger to

deliver minimum boost pressure.

A fuel additive (cerium) is used to lower the oxidation

temperature. With the help of the fuel additive, the

oxidation temperature is lowered to 450 °C.

Initiating regeneration

E51759

1

4

5

3

2

Supervisor software1

Manager software2

Regeneration3

Regeneration is to take place4

Monitoring of the regeneration5

For regeneration of the diesel particulate filter, the PCM

features a separate data record.

The decision on whether, and if so when, regeneration

has to take place must be made by two different software

applications:

• Supervisor software and

• Manager software.

The Supervisor software decides on the basis of the

following parameters whether regeneration should be

carried out:

• Soot load of the diesel particulate filter (value of the

diesel particulate filter differential pressure sensor),

• Distance traveled,

• Operating conditions driven,

• Favorable conditions for regeneration,

• Probability of improved conditions in the near future.

By taking these parameters into account, it is possible

to achieve minimum fuel consumption levels, minimum

oil dilution and optimum performance whilst the vehicle

is in operation.



Strategies

If the Supervisor software makes the decision that

regeneration should be carried out, the Manager software

is informed.

The Manager software monitors the regeneration

process and constantly interrogates the following inputs:

• Coolant temperature,

• Intake air temperature,

• Fuel temperature,

• Exhaust gas temperature,

• Manifold absolute pressure.

Regeneration Process

After the Supervisor software has enabled regeneration,

the following actuations occur in two stages:

Stage 1:

• Deactivation of the EGR system,

• Actuation of the guide vanes of the turbocharger to

deliver minimum boost pressure,

• Driver does not accelerate.

Stage 2:

• Opening of the intercooler bypass,

• Closing of the intake manifold flap,

• Advanced post-injection,

• Retarded post-injection.

If regeneration has commenced, it will be completed,

regardless of the operating condition of the engine.

Regeneration is only stopped then by shutting off the

engine. Regeneration is started again once acceptable

operating conditions are detected by the system.

Regeneration takes a maximum of 10 minutes.

Regeneration cycle

The post-injections result in high oil dilution and must

therefore be kept within limits.

To avoid excessively high oil dilution, a minimum

driving distance has to be maintained between two

regeneration cycles (approx. 350 km).

Depending on operating conditions, the diesel particulate

filter is regenerated every 350 to 1000 km.

Regeneration cycles are increased depending on ash

content, which increases with every regeneration of the

diesel particulate filter.

As the ash content increases, the pores of the diesel

particulate filter become increasingly blocked. This

means that regeneration cycles also become increasingly

shorter.

For this reason, the diesel particulate filter has to be

replaced at a defined service interval (every 60,000 km

at the time of going to print).

Note: Increased oil consumption and reduced fuel

quality (high sulphur content), as well as high fuel

consumption accelerate the build-up of ash in the diesel

particulate filter, shortening regeneration intervals more

quickly.

If the minimum distance between regeneration cycles,

currently 350 km, cannot be adhered to, this is detected

by the diesel particulate filter differential pressure

sensor, and the engine system fault warning lamp is

switched on. The diesel particulate filter must be

serviced early.


StrategiesLesson 3 – Bosch-Common RailSystem

EGR system

E51810

1

9

64

7

3

2

5

8

MAF sensor1

PCM2


Turbocharger(s)4

EGR valve servo motor5

Position sensor (integrated in servo motor)6

Intercooler7

EGR cooler8

Intake manifold flap with servo motor (only in

emission standard IV)9

By using turbochargers, the temperatures in the

combustion chamber rise together with the compression

and combustion performance.

In addition, the combustion temperatures are increased

by using the direct fuel injection method.

Both result in the increased formation of NOX in the

exhaust gas. In order to keep this NOX content in the

exhaust gas within required limits, the EGR system is

becoming increasingly important.

In the part load range, exhaust gas recirculation is

achieved by mixing the exhaust gases with the intake

air. This reduces the oxygen concentration in the intake

air. In addition, exhaust gas has a higher specific heat

capacity than air and the proportion of water in the

recirculated exhaust gas also reduces the combustion

temperatures.

These effects lower the combustion temperatures (and

thereby the proportion of NOX) and also reduce the

amount of exhaust gas emitted. The quantity of exhaust

gas to be recirculated is precisely determined by the



Strategies

PCM. An excessive exhaust gas recirculation rate would

lead to an increase in diesel particulate, CO and HC

emissions due to lack of air.

For this reason, the PCM requires feedback on the

amount of recirculated exhaust gases. This works via

the MAF sensor and a position sensor which is

integrated into the servo motor of the EGR valve.

The servo motor itself is activated by the PCM

depending on requirements.

MAF sensor

The quantity of exhaust gas recirculated when the EGR

valve opens has a direct influence on the MAF sensor

measurement.

During exhaust gas recirculation, the reduced air mass

measured by the MAF sensor corresponds exactly to

the value of the recirculated exhaust gases. If the

quantity of recirculated exhaust gas is too high, the

intake air mass drops to a specific limit. The PCM then

reduces the proportion of recirculated exhaust gas, thus


Position sensor

In the face of increasingly stringent emission standards,

EGR control via the MAF sensor alone is reaching its

limits.

For this reason, a position sensor, which is integrated

into the EGR valve servo motor, is used in addition to

the MAF sensor.

Intake manifold flap

A further step towards minimizing NOX is the

restriction of intake air via the intake manifold flap.

By partial closing of the intake manifold flap a vacuum

is generated behind the intake manifold flap. The

vacuum results in the exhaust gases being drawn in more

efficiently by the engine via the EGR valve, enabling

the EGR rate to be metered more effectively.

This combination (MAF sensor, position sensor and

intake manifold flap control) allows even more precise

metering of the recirculated quantity of exhaust gas.

This way, it is possible to get even closer to the

operating limit with a greater quantity of exhaust gas.

The NOX emissions are thereby reduced to a minimum.

Diagnosis

The EGR control works as a system. The interaction of

individual components is monitored.

Malfunctions lead to increased exhaust emissions which

exceed the EOBD limits. Certain faults also lead to the

EGR system being switched off. Therefore, this is a

MIL active system.

Malfunctions in the EGR system are detected by the

MAF sensor.

In case of a fault, the EGR system is switched off. In

the event of specific faults, the PCM limits the injected

fuel quantity (power output reduction).




E51811

2

1

3

5

67

4

Boost pressure solenoid valve1

MAP sensor2

Intercooler3

Vacuum unit for variable turbine geometry4

Turbocharger(s)5

PCM6

Vacuum pump7

On a variable turbocharger, the boost pressure is

regulated by adjusting the guide vanes. This means that

optimum boost pressure can be set for any operating

condition.

The boost pressure actual value is measured via the

MAP sensor. The set value depends on the speed and

injected fuel quantity as well as the BARO.

When a control deviation occurs, the guide vanes of the

variable-geometry turbocharger are adjusted via the

boost pressure control solenoid valve.



metering system.

Within the framework of EOBD, all the components of

the boost pressure control system are monitored

individually as is their interaction (during system

monitoring).



Strategies

Turbocharger diagnosis

Boost pressure control works as a system. The

interaction of individual components (including the

turbocharger) is monitored.

Malfunctions of the turbocharger and faults of the boost

pressure control solenoid valve or the vacuum system

for the turbocharger actuation result in increased exhaust

emissions which exceed the EOBD limits. Certain faults

also lead to the EGR system being switched off.

Therefore, this is a MIL active system.

Malfunctions in the boost pressure control system are

detected by the MAP sensor.

In the event of a fault, the PCM limits the injected fuel

quantity (power output reduction) and sets a diagnostic

trouble code.


• MIL active: P0045, P0046, P0047, P0048

• Non MIL active: P0234, P0299


E51809

2 3

4

5

8

7

6

9

1

PCM1

High pressure pump2

High pressure chambers for high pressure

generation3

Fuel feed4



Fuel rail7

Solenoid valve8

Injector needle9






Via the high pressure chambers of the common rail

high-pressure pump, fuel is compressed and fed to the

fuel rail.






condition.


fuel combustion.




The fuel pressure sensor continuously informs the PCM

about the current fuel pressure.

Pressure is regulated via the fuel metering valve by

reducing the cross section of this valve accordingly. As

a result, the high-pressure pump delivers a smaller

quantity of fuel (or no fuel at all, depending on the

requirements) until the desired fuel pressure is reached.

Fuel pressure is dependent on engine speed and engine

load.




In the case of fully electronic engine management this

is achieved by the PCM specifying an injected quantity

of 0. The solenoids for fuel injection are therefore no

longer energized and the engine is switched off.


After the engine has been switched off, pressure is

reduced through leakage past the fuel injectors. The rate

of pressure reduction depends on how high the fuel

pressure and fuel temperature are. For safety reasons,

a certain period of time has to elapse before the

high-pressure system is opened after the engine is

stopped (see current Service Literature).

Other strategies

Other strategies include:

• Idle speed control

• Judder damper

• Smooth-running control (cylinder balancing)

• External fuel quantity intervention

These strategies are similar to those for the Delphi

common rail system (see relevant sections in "Lesson

2 – Delphi common rail system")



Strategies

Component overview

1 2

3

13

9

1112

6

5

4

10E48490

7

8


sensor1

Catalytic converter2


sensor3

PCM4

Fuel additive control unit5

Instrument cluster6

Tank flap switch7

Tank flap solenoid8

Fuel additive tank9

Fuel additive pump unit10


Diesel particulate filter with fuel additivesystem


Fuel injector11 Fuel tank12



1

2

3

E48496

Connection – exhaust gas temperature sensor –

diesel particulate filter1

Pipes to diesel particulate filter differential

pressure sensor2

Diesel particulate filter and catalytic converter

housing3

The diesel particulate filter of the 1.6L Duratorq-TDCi

(DV) engine is downstream of the catalytic converter

in the flow direction of the exhaust gases.

Oxidation catalytic converter and diesel particulate filter

are combined in one housing.

The particulate matter contained in the exhaust gas is

deposited in the diesel particulate filter. The pressure

drop across the particulate filter (measured via the diesel

particulate filter differential pressure sensor) is an

indicator for the soot load of the filter.

The soot load capacity of the diesel particulate filter is

limited, however, so that it has to be regenerated at

regular intervals (burning/oxidation of the diesel

particulates).

After regeneration, ash residues that have formed from

the fuel additive, engine oil and fuel remain in the diesel

particulate filter. These constituents cannot be further

converted and can only be deposited in the diesel

particulate filter up to a certain degree.

This means that the diesel particulate filter must be

replaced at prescribed service intervals (see current

Service Literature).




E51450

12

34

Exhaust gas from engine1



Cleaned exhaust gas4

The diesel particulate filter is a honeycomb structure,

the walls of which are made of porous silicon carbide

In addition, the individual ducts are sealed at one side

and offset to each other.

After combustion has occurred, some diesel particulates

may still be present in the exhaust gas. As part of the

filtration process, the exhaust gases loaded with diesel

particulate matter flow into the diesel particulate filter

and are then forced to flow through the porous walls as

a result of the offset position of the sealed channels.

The build up of diesel particulate matter in the

intermediate chambers of the porous walls increases the

filtration effect still further.




Intercooler bypass

E51462

1

23 4

57

8

9

6

10

MAP sensor1

Intake manifold flap housing2

Intercooler bypass3

MAF sensor with integral IAT sensor4

Connecting piece between turbocharger and

intercooler5

Intercooler6

Turbocharger vacuum unit7

Intercooler bypass flap servo motor8

Intercooler/intake manifold flap connection9

Intake manifold flap servo motor10




An intake manifold flap housing has been added to the

intake system in conjunction with the particulate filter

system. The intake manifold flap housing contains the

following components:

• Intercooler bypass flap with servo motor,

• Intake manifold flap with servo motor,

• MAP sensor,

• IAT sensor (not illustrated).

The intake manifold flap creates the connection

between the cooled air from the intercooler and the

intake ports of the engine via the intake manifold flap

housing.

The intercooler bypass valve creates a direct

connection between the compressor side of the

turbocharger and the intake ports of the engine via the

intake manifold flap housing. The intercooler is

bypassed.

The intercooler bypass flap is adjusted via a servo motor

during the regeneration phase of the diesel particulate

filter.

During the regeneration phase the air mass flowing

through the intercooler (regulated by the intake manifold

flap) is reduced.

At the same time, the flow of uncooled air mass via the

intercooler bypass (regulated by the intercooler bypass

flap) is increased.

This reduces the engine's cylinder charge while keeping

the intake air temperatures constant to prevent variations

in exhaust gas temperatures during regeneration.

The position of both valves is dependent on the intake

air temperature. For this reason, there is an additional

IAT sensor in the intake manifold flap housing,

downstream of the intake manifold flap and intercooler

bypass flap (not illustrated).




Fuel additive system – general

E51469

1 2 3

4

56

Fuel tank1

Hoses for fuel additive (top up and ventilation)2

Fuel additive tank3


Fuel additive pipe to fuel injector5

Fuel injector6

The fuel additive system comprises the following

components:

• a fuel additive tank with a fuel additive pump unit,

• fuel additive pipes,

• a fuel injector.

In addition, a tank flap switch and a fuel additive control

unit are installed in the vehicle (not illustrated).

The fuel additive is injected into the fuel tank via the

fuel additive pump unit, the fuel additive pipe and the

fuel injector.

The fuel additive mixes with the diesel fuel in the fuel

tank. The quantity of the fuel additive to be injected is

dependent on the diesel fuel quantity at each refueling.




System components – fuel additivesystem

Fuel additive tank

E48498

1

5

2

3

4

6

Fuel line to fuel tank1

Overflow (when filling)2

Fuel filler connection3

Fuel additive tank4


Vent assembly6

The fuel additive tank is located behind the fuel tank

and is attached to the crossmember. The fuel additive

tank forms a unit together with the fuel additive pump

unit and can therefore only be replaced as a whole.

The fuel additive tank has a capacity of 1.8 liters for an

average total mileage of 60,000 km. Therefore, the fuel

additive has to be topped up according to the service

specifications.

Note: The fuel additive tank cannot be emptied fully.

Once the quantity remaining falls below 0.3 liters, fuel

additive injection ceases (the driver is informed before

this occurs via the relevant warning lamps). The residual

quantity prevents the fuel additive pump from drawing

in air, which could result in incorrect quantities of fuel

additive being metered.

The maximum top-up quantity is therefore 1.5 liters.

Fuel additive pump unit

E48499

3

21

Connection to the fuel tank1

Fuel additive pump2

Piezo sensor3

The fuel additive pump is designed as a

displacement-type pump (piston pump). It feeds the fuel

additive, metered according to the command issued by

the fuel additive control unit, via a short fuel pipe to the

injector where it is injected into the fuel tank.

The piezo sensor at the bottom end of the fuel additive

pump unit contains two sensor elements with the


• They determine changes in the viscosity of the fuel

additive as a result of changes in ambient

temperature.

• They detect when the fuel additive tank is empty

(measurement of the precise fuel level in the fuel

additive tank is also envisaged and will be

implemented at a later date).

In the event of an empty fuel additive tank, initially the

engine system fault warning lamp illuminates. This

means that from this point, only a residual quantity of

fuel additive is available for approximately 250 liters

of fuel. If the fuel additive tank is not refilled, theMIL

illuminates and the fuel additive injection process is

stopped.




Injector

E48500

The injector is connected to the fuel additive tank by

means of a fuel pipe.

The fuel additive pump generates pressure in the fuel

pipe. The injector check valve opens and fuel additive

is fed into the fuel tank.

Fuel additive

Metallic catalysts, cerium and iron, are used as fuel

additives. These accelerate burn-off of the diesel

particulates and lower the temperature at which burn-off

can occur.

Each time after the fuel tank is filled, a metered quantity

of fuel additive is injected into the fuel tank where it

mixes with the fuel.

When combustion takes place, the cerium and iron traces

mix with the particulates from the diesel exhaust gas

and provide for a considerably lower burn-off

temperature.

As a result, the particulate matter collected in the filter

can be burned off at temperatures of just over 450 °C.

The homogeneously bound cerium oxide/diesel

particulate matter is then filtered out by the particulate

filter, where it becomes embedded.

Due to the combination of fuel additives (reduction in

the burn-off temperature of the particles) and the engine

management system (increase in the exhaust gas

temperature) diesel particulate filters can be regenerated

not only under full load conditions, but also in the partial

load range at comparatively low exhaust gas

temperatures typical for urban traffic.




Component overview – system control

E70769

1

2

3

4

5

6

7

8 9

10

11

12

Exhaust gas temperature sensor – diesel

particulate filter1


sensor2

IAT sensor3

Fuel tank flap switch and solenoid (in the tank

flap)4

Piezo sensor on fuel additive pump unit5


PCM7

CAN8




DLC9



Fuel additive pump12


On replacing a PCM or before loading a new software

as well as replacing the diesel particulate filter, always

read the instructions in the current Service Literature.

Control modules

PCM

During the regeneration phase, the PCM partially

assumes control of the system.

During the regeneration phase, completely different

parameters are required for engine management. For

this reason, the PCM is equipped with an additional data

set for the regeneration phase.

The fuel additive system is monitored by a separate fuel

additive control unit which communicates with the PCM

via the CAN data bus.

The PCM and the fuel additive control unit can be

diagnosed by means of WDS via the DLC connection.

Fuel additive control unit

E48493

1


A separate fuel additive control unit is responsible for

fuel additive injection. This is installed on the

right-hand side of the passenger compartment under the

rear seat.

It is connected to the PCM via CAN data bus.

The fuel additive control unit detects when the vehicle

has been refueled on the basis of various input values

and subsequently controls metering of the fuel tank

additives to be injected into the fuel tank.

The fuel additive control unit also features a counter

function. Using this counter, the fuel additive control

unit calculates the liquid level in the fuel additive tank




by recording the frequency with which the fuel additive

pump unit is actuated and the duration of these

actuations.

As soon as the level drops below a specific, calculated

quantity remaining in the fuel additive tank, the engine

system fault warning lamp in the instrument cluster

is actuated, indicating in this case that the quantity of

fuel additive remaining is sufficient for approximately

250 liters of fuel.

This means that in the case of a fuel tank with a capacity

of 50 liters, sufficient fuel additive remains available

for approximately five complete refueling operations

or, for example, for ten refueling operations at 25 liters

each.

Information concerning the actual quantity of fuel added

is sent by the fuel level sensor. With a properly

functioning system, only refueling quantities exceeding

5 liters are registered.

If the engine system fault warning lamp illuminates,

this is a signal to the driver of the vehicle that he should

drive to the nearest Authorized Ford Workshop as soon

as possible.

If this does not happen the MIL is set when the fuel

additive tank has been emptied completely.

To indicate an empty fuel additive tank, the fuel additive

control unit sends the appropriate information via CAN

data bus to the PCM, which logs a DTC and, in turn,

actuates the lamp in the instrument cluster, also via the

CAN data bus.

Note: If one of the previously mentioned lamps

illuminates to indicate that the fuel additive tank is

empty, the corresponding DTC must be cleared in the

fault memory by means of WDS once the fuel additive

tank has been refilled. In addition, the counter must

be reset by means of WDS.

Note: The fuel additive tank cannot be emptied fully.

Once the quantity remaining falls below 0.3 liters, fuel

additive injection ceases (the driver is informed before

this occurs by means of the relevant warning lamps).

The residual quantity prevents the fuel additive pump

from drawing in air, which could result in incorrect

quantities of fuel additive being metered.

Diagnosis

The fuel additive system is a stand-alone system

controlled by the fuel additive control unit.

The fuel additive control unit detects faults in the fuel

additive system and sends these via CAN data bus.

The PCM registers the CAN fault data from the fuel

additive control unit and subsequently logs a

corresponding DTC.

Faults in the fuel additive system can lead to

illumination of both the engine system fault warning

lamp and the MIL.

In the event of CAN communication failure, the MIL

is also actuated.


U0118

Fuel additive pump unit

Function

E48499

3

21

Connection to the fuel tank1

Fuel additive pump2

Piezo sensor3




The fuel additive pump unit consists of the fuel additive

pump and a two-piece piezo sensor.

The internal piezo sensor can only detect when the

fuel additive tank is empty. In conjunction with the

counter of the fuel additive control unit, this device thus

provides additional certainty of detecting an empty fuel

additive tank.

Note: There are plans to enable the external piezo sensor

to detect the precise liquid level and these will be

implemented at a later date.

The external piezo sensor establishes the changing

viscosity of the fuel additive affected by the ambient

temperature and sends this reference value to the fuel

additive control unit.

On the basis of this input signal, the fuel additive control

unit is able to determine precisely the injection duration

for the fuel additive.

The fuel additive pump is actuated by the fuel additive

control unit using pulse width modulation and supplies

the injector on the fuel tank with a precise quantity of

fuel additive due to its defined stroke.

Tank flap switch

Function

E51571

1

2

Solenoid (in tank flap)1

Tank flap switch (reed contact)2

The tank flap switch is incorporated into the fuel filler

neck insert. The actuating solenoid is located in a

bracket on the tank flap.

The tank flap switch is a reed contact and informs the

fuel additive control unit that the fuel tank is filled.

However, the fuel additive control unit only registers

that refueling has taken place if detected by the fuel

level sensor in addition to the tank flap switch signal

and if the vehicle is traveling at a speed of < 3 km/h.

If a clear signal is received from the tank flap switch as

a result of opening and closing the tank flap and if an

increase in the fuel quantity (differential quantity) of at

least 5 liters is detected in the fuel tank once the ignition

has been turned on, the fuel additive control unit

assumes that refueling has taken place.

The fuel additive control unit calculates the fuel additive

quantity to be injected, according to the differential

quantity calculated, and activates the fuel additive pump.




Activation/metering is performed as soon as the vehicle

exceeds a speed of 40 km/h or, if this speed is not

reached, 4 minutes after the engine is first started.

Note: After the fuel additive tank has been topped up

(during scheduled service) the counter in the fuel

additive control unit must be reset. It can be reset by

opening and closing the tank flap in a certain way and

use should be made of this feature (see current

Service Literature). Resetting the counter via the tank

flap switch is not possible if either the engine system

error warning lamp or the MIL has illuminated as a

result of the fuel additive tank becoming empty. In this

case, the counter must be reset using the WDS.

When the tank flap is closed, the tank flap switch is

open.

Effects of faults

If the signal from the tank flap switch fails, small

refueling quantities (below 10 liters) cannot be detected.

The software on the fuel additive control unit has been

designed to only allow fuel additive to be injected in

the case of a missing signal from the tank flap switch

if the refueling quantity is at least 10 liters.

The reason for this is that, in the worst case scenario,

the vehicle may, for example, have been rolled onto a

slope with the " ignition OFF". Then, when the ignition

is next switched on, the fuel additive control unit could

register an increased quantity of fuel via the fuel level

sensor and might misinterpret this as a refueling

operation. To prevent fuel additive from being injected

unnecessarily, if the tank flap switch is faulty, the fuel

level difference is increased from at least 5 liters to a

minimum of 10 liters.

If the signal fails, the engine system error warning lamp

is actuated.

IAT sensor

Function

E51583

1

2

3

IAT sensor1



During regeneration of the diesel particulate filter, a

constant intake air temperature in conjunction with the

intercooler bypass and the intake manifold flap is of

great importance.

For this reason, an additional IAT sensor is installed in

the airflow, downstream of the intercooler bypass. This

is used to set the most favorable air intake temperature

during the regeneration phase.

When the engine is operating normally, the IAT sensor

has no function.

Effects of faults

In the event of a fault, the PCM performs the

calculations using a substitute value.

Diagnosis

The IAT sensor is checked by the monitoring system

for short (to ground and positive) and open circuits.




As the PCM is able to use a substitute value to perform

its calculation when the signal fails, the impact of this

failure on the regeneration phase of the particulate filter

is only minimal. The EOBD limits are not affected by

this. Therefore, this is a non MIL active component.

Possible diagnostic trouble codes: P0097, P0098.

Exhaust gas temperature sensor

Function

E48497

The exhaust system of the 1.6L Duratorq-TDCi (DV)

engine incorporates a diesel particulate filter exhaust

gas temperature sensor.

The exhaust gas temperature required for burning off

the diesel particulates (at least 500 °C to 550 °C) is

detected by the diesel particulate filter exhaust gas

temperature sensor and transmitted to the PCM.

The temperature of the exhaust gas prior to passing

through the particulate filter is used by the PCM as an

input parameter for calculation purposes. The values of

other relevant parameters are also taken into account.



can be initiated.

Moreover, the exhaust gas temperature is monitored

during the regeneration process.

Effects of faults

In the event of a fault, the PCM reverts to a substitute

value.

The substitute value is calculated on the basis of:

• Coolant temperature,

• Engine speed,

• Engine load.

Diagnosis

The exhaust gas temperature sensor verifies that the

incoming signal is within the specified limits and checks

it for plausibility.

In the event of a fault, the exhaust gas emissions are not

affected and this is therefore a non MIL active

component.


P0427, P0428.

Diesel particulate filter differentialpressure sensor

Function

E48494

The diesel particulate filter differential pressure sensor

measures the current pressure differential upstream and

downstream of the diesel particulate filter in the exhaust

gas stream.




For this purpose, there is a pipe connection upstream

and downstream of the particulate filter (see illustration

below).

The readings are converted by the diesel particulate

filter differential pressure sensor into a voltage signal

and signaled to the PCM.

E51610

1

3 2


Pipe connections – diesel particulate filter

differential pressure sensor2


The soot particles and ash collected in the diesel

particulate filter result in a pressure change of the

exhaust gas upstream and downstream of the diesel

particulate filter. The altered pressure value due to the

soot load is used by the PCM as an input parameter for

determining soot load.

If the measured value exceeds the stored maximum

value, regeneration of the particulate filter is initiated,

taking into account the necessary boundary conditions.

In addition, the diesel particulate filter differential

pressure sensor is mainly used for fault diagnosis.

Effects of faults

In the event of a fault the engine power output is reduced

by the PCM by reducing the injected fuel quantity.

Diagnosis

The monitoring system performs the following checks

using the diesel particulate filter differential pressure

sensor:


• Diesel particulate filter efficiency

• Diesel particulate filter overloaded,

• Diesel particulate filter blocked,

• Monitoring of the maximum regeneration attempts

in the lower load range.

The plausibility check is divided into two tests:

• With the engine running: The differential pressure

is measured across the diesel particulate filter. This

is determined according to the difference between

the anticipated pressure of the exhaust gas stream as

calculated by the PCM and the actual pressure of the

exhaust gas stream before and after it passes through

the particulate filter. This test is performed under

certain operating conditions (depending on coolant

temperature, engine speed and engine load –

regeneration not activated). Assuming that these

conditions are met, the sensor signal must be within

the specified limit values.

• With the engine switched off: Here, the differential

pressure is measured before the engine is started or

immediately after it has been switched off. If the

differential pressure calculated via the diesel

particulate filter is greater than the value specified

by the PCM, this is recognized as an implausibility.

The diesel particulate filter efficiency test determines

whether the filter material in the diesel particulate filter

is in sound condition.

The diesel particulate filter element itself poses a certain

resistance to the exhaust gas stream that is calculated

by the PCM. To achieve the calculated exhaust gas

stream, the test is performed under certain operating

conditions.




If the value measured here is below the minimum value

calculated, the diesel particulate filter is recognized as

inefficient.

A diesel particulate filter is recognized as overloaded

if the differential pressure across the diesel particulate

filter (under certain operating conditions) exceeds the

overload limit calculated by the PCM.

A diesel particulate filter is recognized as blocked if

the differential pressure across the diesel particulate

filter (under certain operating conditions) exceeds the

blocking limit calculated by the PCM.

Monitoring of the maximum regeneration attempts

in the lower load range: The diesel particulate filter

regeneration system is designed to enable regeneration

to be performed even under poor conditions (low coolant

temperature, engine speed and engine load).

In the worst-case scenario the system may start

regeneration attempts but be unable to complete them.

These attempts are counted by the PCM. If the

maximum number of regeneration attempts is reached,

this results in a fault entry the next time the ignition is

switched on.

Certain faults lead to increased diesel particulate

emissions, with the result that the EOBD limits are

exceeded. It is therefore a MIL active component.


P2455, P2002, P242F, P2458, P2459

Intake manifold flap servo motor

Function

E513731

2



The intake manifold flap has another function in addition

to restricting the intake air for exhaust gas recirculation

and closing the intake system when the engine is

stopped.

During the regeneration phase the intake manifold flap

closes off the airflow via the intercooler, depending on

requirements. At the same time, the uncooled charge

air is fed via the intercooler bypass flap.

The intake manifold flap servo motor incorporates a

DC motor and a position sensor which detects the

current position of the intake manifold flap.

Effects of faults

In the event of a fault, limited regeneration is still

possible, depending upon how high the intake air

temperature is and the operating condition of the engine.




Intercooler bypass flap servo motor

Function

E51674

During the regeneration phase, the intercooler bypass

flap opens, enabling uncooled charge air to be directed

to the combustion chambers.

The uncooled air prevents cooling of the combustion

chamber when engine speeds/engine loads are low and

this promotes the regeneration of the diesel particulate

filter.

The intercooler bypass flap servo motor incorporates a

DC motor and a position sensor which detects the

current position of the intake manifold flap.

E51722

2

1

1

3

4

PCM1

Servo motor2

Position sensor3

DC motor4

The DC motor is supplied with battery voltage by means

of the ignition relay in the battery junction box.

The actuation of the DC motor and therefore the

adjustment of the intercooler bypass flap is performed

by the PCM connecting to ground (pulse width

modulated).

The position sensor is supplied with a reference voltage.

The voltage drop across the position sensor (variable

resistance via sliding contact) signals the precise angular

position of the intercooler bypass flap to the PCM.




Effects of faults

In the event of a fault, limited regeneration is still

possible, depending upon how high the intake air

temperature is and the operating condition of the engine.

Diagnosis

Monitoring of the intercooler bypass flap (by means of

the position sensor) includes the following checks:

• Reference voltage of the position sensor

• Limit value range check,


• Control deviations,

• Sticking intercooler bypass flap.

Since the EGR system only works to a limited extent

in the event of a fault, this is a MIL active component.

Possible diagnostic trouble codes: P022A, P022B,

P022C, P024A, P024B, P024E, P024F, P0033, P138C.




Overview

E51106

7

6

G

A

B

CD

E

F

5

12

3

4

8

Fuel feedA

Outlet pipe for excess fuel deliveredB

High pressure lineC

Fuel injection lineD

Fuel return from high-pressure pumpE

Leak-off pipeF

Fuel return to fuel tankG

High pressure pump1

Fuel rail (common rail)2

Fuel injector3


Fuel return collector pipe5


Fuel SystemLesson 3 – Bosch-Common RailSystem

Fuel filter6 Fuel tank7

Fuel level sensor8

General

Function



pressure pump.





Leak-off fuel from the fuel injectors and/or returning

fuel from the high pressure pump are fed back into the

fuel tank.

Possible causes of defects in fuel pipes and thefuel tank


bending.










Irregular idling







refueled.







Fuel System

Fuel filter

Function

E43249

1

4

3

2

Fuel feed to the high-pressure pump1

Water drain screw2

Electric fuel pre-heater3

Fuel feed from the fuel tank4

The fuel filter clipped into transmission end of the

cylinder head is equipped with an electric fuel heater.

There is a water drain screw in the top housing section

of the filter for draining purposes.

In accordance with the service intervals, the fuel filter

must be drained of water regularly.

E51107

1

2 5

6

1

15 30

3

2

43

2

1

5

7

6


Fuel heater relay2

Fuse (10A)3

Fuse (15A)4

Ground5

Electric fuel heater in the fuel filter6

Ground7

The electric bi-metal controlled fuel heater works

independently of the PCM.

It is actuated via a fuel heater relay when the ignition

is switched on (ignition ON). However, the activation

of the heating element is dependent on the current

temperature.

Below a fuel temperature of 0 to –4 °C, the circuit is

closed by the bi-metal and the heating element is

energized.

The bi-metal opens the circuit at a fuel temperature

between 1 and 5 °C and ends the heating phase.




filter.



Effects of faults


Irregular idling





E51108

3

4

5

6

789

1

2



Fuel System

Fuel injector1


Leak-off pipe3


Transfer pump5

High pressure line6

High pressure pump7

Fuel rail8


High pressure pump

Overview

High pressure pump CP3.2

E51109

1

2 3 4 5

6

Transfer pump1


Pump plunger3

Eccentric4

Drive shaft5

Pump housing6



High pressure pump CP1H

E70770

2

3

4

5

1


Fuel return port2

Fuel supply port3

Transfer pump4

High pressure port (to fuel rail)5

Two different types of high pressure pumps are used in

the Delphi common rail system:

• High pressure pump CP3.2 and

• High pressure pump CP1H

With the launch of the Focus C-MAX 2003.75

(06/2003-), initially only the CP3.2 was installed. Over

time the CP3.2 was being replaced increasingly by the

CP1H and this pump was installed from the outset for

certain new launches.

The following table shows the fuel injection timing of

the CP1H based on the vehicle.

The function of the high pressure pump CP1H is

essentially the same as that of the CP3.2.

Introduction of CP1HVehicle

October 2004Fiesta 2002.25 (11/2001-)

February 2005Focus C-MAX 2003.75

(06/2003-)/Focus 2004.75

(07/2004) with 67 kW (90

hp)

May 2005Focus C-MAX 2003.75

(06/2003-)/Focus 2004.75

(07/2004) with 82 kW

(110 hp)

Function of the high-pressure pump

First, the fuel is drawn from the tank by the transfer

pump mounted on the high-pressure pump and delivered

to the high-pressure pump.

The high-pressure pump provides the interface between

the low and the high pressure systems. Its function is to

always provide sufficient compressed fuel under all

operating conditions and for the entire service life of

the vehicle.

The high-pressure pump permanently generates the

high system pressure for the fuel rail. Therefore, the

compressed fuel does not have to be supplied under high

pressure for each injection process individually, unlike

systems with distributor type injection pumps.

Due to the permanently high system pressure, injection

quality is optimized over the entire engine speed/load

range.



Fuel System

Flow of fuel through the high-pressure pump

E51111

5

42

6

E

D

C3

B

F

A

1

7 8

9

G

To the fuel injectorsA

High fuel pressureB

Flow of fuel through the high-pressure pumpC

Return flow to transfer pumpD

Fuel feedE

Fuel injector leak-offF

Fuel returnG

Fuel rail1

High-pressure range2

Pressure restriction3


Overflow throttle valve5

High pressure pump6

Transfer pump7

Fuel filter8

Fuel tank9



Transfer pump

E51110

2

31

Intake side1

Drive gear2

Delivery side3

The transfer pump is designed as a gear pump and

delivers the required fuel to the high-pressure pump.

Essential components are two counter-rotating, meshed

gear wheels that transport the fuel in the tooth gaps from

the intake side to the pressure side.

The contact line of the gears forms a seal between the

intake side and the pressure side and prevents the fuel

from flowing back.

The delivery quantity is approximately proportional to

engine speed. For this reason, fuel-quantity control is

required.

For fuel-quantity control purposes, there is an overflow

reducing valve incorporated in the high-pressure pump.

Overflow throttle valve

E51112

6 6 6

3 3 3

4

4

8

7 7 7

9

5

CBA

5 5

1

2

1

2

1

2

4

8



Fuel System

Low engine speedsA

Increasing engine speedsB

High engine speedsC

Transfer pump pressure1

Time2

Compression spring3

Orifice4

To the high-pressure chambers5

Control piston6

Lubrication/cooling/ventilation – high-pressure

pump7

High-pressure pump cooling bypass8

Return bypass to transfer pump9

High-pressure generation (up to 1600 bar) means high

thermal load on the individual components of the

high-pressure pump. The mechanical components of

the high-pressure pump must also be lubricated

sufficiently to ensure durability.

The overflow reducing valve is designed to ensure

optimum lubrication or cooling for all operating

conditions.

At low engine speeds (low transfer pump pressure) the

control piston is moved only slightly out of its seat. The

lubrication/cooling requirement is correspondingly low.

A small amount of fuel is released to lubricate/cool the

pump via the restriction at the end of the control piston.

NOTE: The high-pressure pump features automatic

venting. Any air in the high-pressure pump is vented

through the restriction.

With increasing engine speed (increasing transfer pump

pressure), the control piston is moved further against

the compression spring.

Increasing engine speeds require increased cooling of

the high-pressure pump. Above a certain pressure, the

high-pressure pump cooling bypass is opened and the

flow rate through the high-pressure pump is increased.

At high engine speeds (high transfer pump pressure),

the control piston is moved further against the

compression spring. The high-pressure pump cooling

bypass is now fully open (maximum cooling).

Excess fuel is transferred to the intake side of the

transfer pump via the return bypass.

In this way, the internal pump pressure is limited to a

maximum of 6 bar.



High pressure generation

E51113

9

8

7

3

2

1

4

6 5

High pressure to fuel rail1

Outlet valve2

Spring3

Fuel feed4

Drive shaft5

Eccentric cam6


Pump plunger8

Inlet valve9

The high-pressure pump is driven via the drive shaft.

An eccentric element is fixed to the drive shaft and

moves the three plungers up and down according to the

cam lobes of the eccentric element.

Fuel pressure from the transfer pump is applied to the

inlet valve. If the transfer pressure exceeds the internal

pressure of the high pressure chamber (pump plunger

in TDC position), the inlet valve opens.

Fuel is now forced into the high-pressure chamber,

which moves the pump plunger downwards (intake

stroke).

If the BDC position of the pump plunger is exceeded,

the inlet valve closes due to the increasing pressure in

the high-pressure chamber. The fuel in the high-pressure

chamber can no longer escape.

As soon as the pressure in the high-pressure chamber

exceeds the pressure in the fuel rail, the outlet valve

opens and the fuel is forced into the fuel rail via the

high-pressure connection (delivery stroke).

The pump plunger delivers fuel until TDC is reached.

The pressure then drops so that the outlet valve closes.



Fuel System

As the pressure on the remaining fuel is reduced, the

pump plunger moves downward.

If the pressure in the high-pressure chamber falls below

the transfer pressure, the inlet valve reopens and the

process starts again.

Zero delivery valve

E511142 3

14

From high-pressure chamber annular channel1

Zero delivery valve2

Calibrated bore (ø = 0.4 mm)3

To transfer pump4

The zero delivery valve is located between the annular

channel that is connected to the inlet valves of the

high-pressure chambers and the fuel metering valve.

Even in the fully closed state, the fuel metering valve

(see "Lesson 3 – Engine management system") is not

completely sealed. In other words, a small amount of

leakage in the annular channel continues to pass to the

high pressure chambers due to the transfer pump

pressure. As a result, the inlet valves are opened and an

undesirable pressure increase may occur in the high

pressure system.

To prevent this, the zero delivery valve features a

calibrated bore. In this way, excess fuel is fed back to

the intake side of the transfer pump.


Structure and task

E43248

1



The common rail performs the following functions:



Pressure fluctuations are induced in the high-pressure

fuel system due to the operating movements in the

high-pressure chambers of the high-pressure pump and

the opening and closing of the solenoid valves on the

fuel injectors.

Consequently, the fuel rail is designed in such a way

that, on the one hand, it possesses sufficient volume to

minimize pressure fluctuations, but, on the other hand,

the volume in the fuel rail is sufficiently low to build

up the fuel pressure required for a quick start in the

shortest time possible.

Function



accumulator. The fuel is then delivered to the individual

fuel injectors via the four injector tubes which are all

of the same length.




process, the pressure in the fuel rail remains almost

constant.


In order that the engine management system can

determine the injected fuel quantity precisely, as a

function of current fuel pressure in the fuel rail, a fuel

pressure sensor is provided on the fuel rail (see Lesson

3).

High pressure fuel lines

E43246



NOTE: After disconnecting one or more high pressure

fuel lines, these must always be replaced. Reason: The

reason for this is that leaks can occur when re-tightening,

due to distortion of the connections of the old lines.

The high-pressure fuel lines connect the high-pressure


fuel injectors.

Fuel injectors

E43245

3

4

2

5

1

7

6

Connection, leak-off pipe1

Retainer2

Plastic ring3

Seal ring4

Combustion chamber seal5

High pressure fuel line connection6


NOTE: The combustion chamber sealing rings must

not be reused.

The exact procedure for the correct installation of

the sealing rings and the plastic rings can be found


Start of injection and injected fuel quantity are adjusted

via the fuel injectors.



Fuel System

To achieve the optimum injection timing and exact

injected quantity, the Bosch common rail system uses

special fuel injectors with a hydraulic servo system and

electric actuator (solenoid valve).

The fuel injectors are actuated directly by the PCM.

The PCM specifies the injected quantity and the

injection timing.


blocks:

• Injector nozzle,

• Hydraulic servo system,

• Solenoid valve.



Operating principle of the fuel injectors

E51115

BA

11

12 13

9

8

7

6

10

11

1

2

9

8

7

6

5

4

310


Fuel injector openB

Solenoid valve coil1

Feed channel2

Valve ball3

Feed restriction4

Feed channel to nozzle prechamber5

Injector needle6

Nozzle prechamber7

Injector needle control spring8

Valve control piston9

Valve control chamber10



Fuel System

Outlet restriction11 Fuel return12


The fuel is fed from the high-pressure connection via a

feed channel into the nozzle prechamber and via the

feed restriction into the valve control chamber.

The valve control chamber is connected to the fuel return

via the outlet restriction, which can be opened by means

of a solenoid valve.


In its closed state (solenoid valve de-energized) the

outlet restriction is closed by the valve ball so that no

fuel can escape from the valve control chamber.

In this state, the pressures in the nozzle prechamber and

in the valve control chamber are the same (pressure

balance).

There is, however, also a spring force acting on the

injector needle spring so that the injector needle remains

closed (hydraulic pressure and spring force of the

injector needle spring). No fuel can enter the combustion

chamber.

Fuel injector opens

The outlet restriction is opened via actuation of the

solenoid valve. This lowers the pressure in the valve

control chamber, as well as the hydraulic force on the

valve control piston.

As soon as the hydraulic force in the valve control

chamber falls below that of the nozzle prechamber and

the injector needle spring, the injector needle opens.

Fuel is now injected into the combustion chamber via

the spray holes.

Fuel injector closes

After a period determined by the PCM, the power supply

to the solenoid valve is interrupted.

This results in the outlet restriction being closed again.

By closing the outlet restriction, pressure from the fuel

rail builds up in the valve control chamber via the feed

restriction.

This increased pressure exerts an increased force on the

valve control piston. This force and the spring force of

the injector needle spring now exceed the force in the

nozzle prechamber and the injector needle closes.

Note: The closing speed of the injector needle is

determined by the flow rate at the feed restriction.

Injection terminates when the injector needle reaches

its bottom stop.

Indirect actuation

Indirect actuation of the injector needle via a hydraulic

booster system is used because the forces required for

rapid opening of the injector needle cannot be generated

directly with the solenoid valve.

The "control quantity" therefore required in addition to

the injected fuel quantity enters the fuel return via the

orifices in the control chamber.

Leak-off quantities

In addition to the control quantity there are leak-off

quantities at the injector needle and valve control piston

guide.

These leak-off quantities are also discharged into the

fuel return.




E51116

0115440 136080F DDFO

760680

3841501517242809

12

Fuel injector1

Identification number2





identification number which is located on the outside


To ensure optimum fuel metering, the PCM must be

informed of a change of fuel injector.

Furthermore, once new PCM software has been loaded

via WDS, the fuel injectors must also be configured

using it.

This is achieved by inputting the 8-digit identification

number (divided into two blocks of four on the fuel

injector) into the PCM by means of WDS and taking

into account the corresponding cylinder.



• Increased black smoke formation,

• Irregular idling




Fuel injector leaks


needles

Irregular idling



Fuel System


1. How does the system respond to serious malfunctions at the fuel metering valve?

a. From an engine speed of 2000 rpm upwards, the injected fuel quantity, and thereby engine power, is reduced.

b. The injected quantity and consequently the engine performance is reduced across the entire speed range.

c. The engine cuts out or cannot be started.

d. The injected fuel quantity is increased accordingly to reduce the excess pressure in the fuel system.

2. What is avoided with the aid of the BARO sensor in the PCM?

a. excessively high engine speeds which cause the engine to overheat at increasing geographic altitudes

b. intercooling at increasing geographic altitudes

c. damage to the turbocharger and black smoke formation at increasing geographic altitudes

d. damage to the EGR system at increasing geographic altitudes

3. What is the purpose of opening the intercooler bypass flap?

a. The cylinder charge of the engine is reduced.

b. The cylinder charge of the engine is increased.

c. A more efficient exhaust gas recirculation

d. Improved idle speed stabilization

4. Which of the following statements about the high-pressure system is false?

a. The zero delivery valve prevents undesired opening of the fuel injectors when the fuel metering valve is

closed.

b. The fuel metering valve controls the opening cross-sectional area of the feed orifice to the high-pressure

chambers.

c. The identification number on the fuel injectors serves as a coefficient of correction for the PCM.

d. The fuel high-pressure lines can be reused as required following disconnection.


Test questionsLesson 3 – Bosch-Common RailSystem






• specify the components of the diesel particulate filter system.

• explain how the diesel particulate filter works.

• name and describe the modifications to the air intake system.

• explain the electrical/electronic components of the diesel particulate filter system.






ObjectivesLesson 4 – Siemens-Common RailSystem

Overview

1.4L Duratorq-TDCi (DV) diesel/2.0L Duratorq-TDCi (DW) diesel

1

3

5

6

7

8

9

10

11

12

13

14

15

16 17 18

1920

21

22

23

4

2

24 25

26

27

28

29

30

31

32

33

3435

36

37

38

E70402


Lesson 4 – Siemens-Common RailSystem

MAF sensor1

MAP sensor (not on all versions)2


IAT sensor (not on all versions)4


ECT sensor6

CMP sensor7

CKP sensor8

Turbocharger position sensor9

APP sensor (2002.25 Fiesta)10

APP sensor (2003.75 C-MAX)11

Stoplamp switch12

BPP switch13

CPP switch14

VSS (vehicles with no ABS)15


Ignition switch17

Vehicle battery18

Oil pressure switch (not on all versions)19

Instrument cluster20

DLC21

'Smart charge' alternator control system22

PCM23

CAN24

DLC25

Fuel injectors26

Turbocharger guide vane adjustment solenoid

valve (not on all versions)27

Intake manifold flap solenoid valve (not on all

versions)28

EGR valve solenoid valve (not on all versions)29

High pressure pump actuators (fuel metering

valve and fuel pressure control valve)30

A/C compressor and fan control magnetic clutch31

Electric PTC (Positive Temperature Coefficient)

booster heater (not on all versions)32

PCM relay33

Sheathed-type glow plug relay34

Electrically-controlled EGR valve (not on all

versions)35

Bypass solenoid valve36

Shutoff solenoid valve37

Electrically actuated intake manifold flap (1.4L

Duratorq-TDCi (DV) diesel, emission standard

IV)

38



1.8L Duratorq-TDCi (Kent) diesel

E70403

1

3

5

6

7

8

9

10

11

12

13

14 15 16

1718

19

20

22

4

23 24

2 25

26

27

28

29

30

31

21



MAF sensor1

MAP sensor2


IAT sensor4


CHT sensor6

CMP sensor7

CKP sensor8

KS9

APP sensor10

Stoplamp switch11

BPP switch12

CPP switch13


Ignition switch15

Vehicle battery16


Gateway *18

Intake manifold flap position sensor (certain

versions)19

Electric EGR valve20

'Smart charge' alternator control system21

PCM22

CAN23

DLC24

Fuel injectors25


High-pressure pump actuators (fuel metering

valve and fuel pressure control valve)27

A/C compressor and fan control magnetic clutch28

PCM relay29

Sheathed-type glow plug relay30


actuator **31

* May be, for example, instrument cluster or

GEM

** Depending on the version with feedback or

without feedback to the PCM

Characteristics

The following components originate from the Siemens

company:

• High-pressure pump (with fuel metering valve and

fuel pressure control valve),

• Fuel injectors,

• PCM.


required and conveys it into the fuel rail. The fuel

metering is carried out through electrical actuation of

the fuel injectors by the PCM.

Special features

Piezo-controlled fuel injectors are used in the Siemens

common rail system.

Note: With these fuel injections, the wiring harness

connectors must not be disconnected from the fuel

injectors while the engine is running. Otherwise, this

may lead to major engine damage.




MAF sensor

After replacing a MAF sensor it may be necessary to

perform a parameter reset with the aid of WDS. In this

regard, refer to the instructions in the current Service

Literature.

Electric EGR valve

After replacing the electric EGR valve a parameter reset

must be performed via WDS in the PCM.


In the 1.8L Duratorq-TDCi (Kent) diesel engine in the

S-MAX/Galaxy 2006.5 (02/2006-) after replacing the

intake manifold flap position sensor an initialization

must be performed with the aid of WDS.


On replacing the PCM following a PCM crash





After replacing the diesel particulate filter a parameter

reset must be performed via WDS in the PCM.

In some versions it may be necessary after replacing

the diesel particulate filter differential pressure

sensor or the PCM to reset the parameters for the diesel

particulate filter differential pressure sensor. In this

regard, always refer to the instructions in the current

Service Literature.

PCM

E43288

The Siemens PCM is the main component of the engine



them and calculates the signals for the actuators (for

example fuel injectors, boost pressure control valve,

EGR valve, etc.) based on them.






a processing unit.

Note: The further "functioning" is similar to that for the


"Lesson 2").

Diagnosis

The PCM monitors to ensure correct operation.

Malfunctions are therefore detected and indicated using

a relevant diagnostic trouble code entry.

Faults which permit continued running of the engine

are generally MIL active.

Faults which lead to the engine stopping are non MIL

active.

Possible diagnostic trouble codes: P0606, P0A94,

P0A09, P0A10, P1563, P0685, P0686, P0687.



PCM identification markings

E53687

S3

1

2

Ford part number1

Serial number2

Manufacturer's number3

At the top of the PCM housing there is a sticker with

the appropriate PCM identification markings for the

relevant engine.



Glow plug control

E53688

1

2

3 57

864







PCM7

Instrument cluster with glow plug warning

indicator8

Note: The glow plug control functions similar to that

in the Bosch common rail system (see "Lesson 3 - Bosch

common rail system" in this Student Information).



MAP sensor

Function

E53690

1 2

MAP sensor1

IAT sensor2

NOTE: Not all versions are equipped with a MAP

sensor. In these versions, the boost pressure is calculated

from the engine speed, intake air mass and BARO

parameters. These versions are equipped with a fixed

geometry turbocharger with a pneumatic bypass valve

(waste gate).

The MAP sensor is located in the air intake tract

downstream of the intercooler. The MAP sensor has the


• Measuring the current boost pressure,

• Calculating the air density for adapting the injected

quantity and the injection timing,

• Calculating the turbocharger outlet temperature.

Effects of faults

In the event of a fault, the guide vanes of the variable

geometry turbocharger are closed completely. Boost

pressure is minimized.

Furthermore, the EGR system is deactivated and the

injected fuel quantity is appreciably reduced (reduced

engine power output).

Diagnosis

Within the framework of EOBD, the proper functioning

of the MAP sensor is of great importance.

Malfunctions lead to significantly increased emissions,

as the EGR system is switched off and the boost pressure

reduced to a minimum. For this reason, it is a MIL

active component.

Monitoring of the MAP sensor consists of altogether

three checking routines:

• The range check determines whether the sensor

values are within the limits. If the limits are not

achieved or are exceeded for a certain period, the

PCM interprets this as an open control loop or a short

circuit.

• The rise/fall check identifies intermittent faults. This

indicates a loose contact at the sensor connector,

among other things.

• The plausibility check compares the MAP sensor

signal with the BARO sensor signal.

The range check is activated when the ignition is

switched on, provided that the PCM does not have a

power supply fault.

If the MAP sensor voltage exceeds the maximum limit,

the PCM interprets this as a short to positive.

If the MAP sensor voltage is below the minimum limit,

the PCM interprets this as an open control loop or a

short to ground.


SensorsLesson 4 – Siemens-Common RailSystem

The rise/fall check is also activated after the ignition

is switched on, provided there is no fault in the power

supply voltage to the sensor.

If the PCM identifies extreme, illogical voltage jumps

below/above the limits, a relevant DTC is stored.

The plausibility check takes place when the ignition is

switched on (engine off). The plausibility check is only

performed if the limit check was completed without any

faults.

A prerequisite for this check, however, is that there is

no plausibility fault entry stored in the fault memory of

the PCM.

The PCM compares the current pressure at the MAP

sensor with the pressure measured at the BARO sensor

for a determined period.

If the PCM detects an excessive deviation from the

target map data, the PCM concludes that the MAP

sensor is defective.

Typical malfunction limits:

• Sensor voltage < 0.098 V, corresponds to approx.

0.133 bar

• Sensor voltage > 4.8 V, corresponds to approx. 2.5

bar

• Difference between MAP sensor und BARO sensor

> 0.2 bar.


P0237.

IAT sensor

Note: not all versions are equipped with an IAT sensor.

For these versions the intake air temperature

(downstream of the turbocharger) is calculated by the

IAT sensor integrated in the MAF sensor (see

"Combined IAT sensor and MAF sensor" in this lesson).

Function

The IAT sensor is designed as an NTC thermistor and

is located in the intake tract, downstream of the

turbocharger.

It detects the charge air temperature in order to

compensate for the temperature influence on the density

of the charge air.

The IAT signal influences the following functions:



• EGR system.

Effects of faults

In the case of a fault, the PCM operates using a

substitute value. This substitute value is derived from

the ECT and fuel temperature.

Diagnosis

The PCM constantly checks whether the IAT sensor

values are within the limits.

If the maximum limits are exceeded for a determined

time, this is interpreted by the PCM as an open control

loop or a short to positive.

If the minimum limits are not reached for a determined

time, this is interpreted by the PCM as a short to ground.

The rise/fall check permits the system to detect

intermittent faults (for instance a loose connector

contact).

In vehicles with a diesel particulate filter system

(Emission Standard IV) a further check, the plausibility

check, has been implemented.

For the plausibility check, the signals of the ECT sensor,

the fuel temperature sensor, the IAT sensor in the MAF

sensor and the separate IAT sensor are compared with



Sensors

one another once the engine has cooled down. In this

condition, the temperature values are approximately the

same.

If the check reveals that the IAT sensor values deviate

from the other values by more than a specified limit,

the IAT sensor is recognized as implausible and a DTC

is stored.

BARO sensor

Function

The BARO sensor is located in the PCM and measures

the ambient air pressure.

The further functioning is similar to that for the Bosch

common rail system (see relevant section in "Lesson

3").

Note: some versions (with fixed-geometry turbocharger)

are not equipped with a MAP sensor for detecting the

actual boost pressure. In these versions, the BARO

sensor signal is used together with the engine speed and

air mass signals to calculate the boost pressure.

Effects of faults

In the event of a fault, the signal from the MAP sensor

is used to determine the ambient air pressure.

If both sensors (BARO und MAP) are defective, the

PCM uses a substitute value. In this case, the injected

fuel quantity and therefore engine performance is


Diagnosis

The PCM continuously checks the BARO sensor for

short circuits (to ground and positive) and for open

control loop.

As already described with regard to the MAP sensor, a

comparison (plausibility check) is performed between

the BARO sensor and the MAP sensor when the ignition

is switched on (engine off).

If the PCM detects a fault during the plausibility

check, the system assumes that the MAP sensor is

defective. As the BARO sensor is integrated into the

PCM, it is assumed that malfunctions of the BARO

sensor are extremely improbable.

Depending on the vehicle version a faulty BARO sensor

may have a greater or lesser effect on the exhaust

emissions. Depending on this fact the component can

be classified as MIL active or non MIL active.


• Sensor voltage < 2.2 V

• Sensor voltage > 4.36 V


P2229.



Turbocharger position sensor (certainversions only)

E53955

1

2

3

Turbocharger position sensor1

Turbocharger vacuum unit2

Variable geometry turbocharger3

On some versions with variable geometry turbochargers,

a turbocharger position sensor is located at the end of

the vacuum unit.

This position sensor further optimizes the boost pressure

control. This has a positive effect on exhaust emissions

and fuel consumption.

The position sensor is directly connected to the

diaphragm in the vacuum unit. When the guide vanes

are adjusted (by means of a vacuum, via the boost

pressure control solenoid valve, the PCM determines

the exact position of the guide vanes via the turbocharger

position sensor.

Effects of faults

No substitution strategies are available in the case of a

fault. Following the detection of a fault, the boost

pressure control switches to open loop control.

The PCM treats this fault in the same manner as a MAP

sensor fault and reduces the engine power output

(reduction of injected quantity).

Diagnosis

Monitoring of the turbocharger position sensor

comprises the following checks:

• Short circuits and open circuits. A check is carried

out to see if the signal falls within its limits.

• Logical rise/fall rate of the signal. Intermittent errors

(e.g. loose contact for a plug) are determined.

• End stop adjustment for fully opened guide vanes.

If too great a deviation is detected during end stop

adjustment, it indicates a blockage to the adjustment

of a vane.

• Control deviation check. A check is made via the

position sensor as to whether the guide vanes adopt

the correct position smoothly during adjustment.



• Rise/fall rate = 2 V / 10 ms

• Control deviation check > ± 30%


P2565, P2566.

ECT sensor

Function

The ECT sensor is located in the small coolant circuit

of the engine and measures the coolant temperature.

The voltage value supplied by the ECT sensor is

assigned to a corresponding temperature value by the

PCM.

The ECT is used for the following calculations:

• Idle speed,




Sensors


• EGR quantity,



warning indicator

• Fan control

Effects of faults

In the event of a fault, the PCM operates using a

substitute value (based on the IAT and fuel temperature).

This calculated substitute value serves as an initial value.

To this value, the PCM adds the value of the additional

temperature increase every 10 seconds until the

maximum limit of the PCM substitute value is reached.

During this phase, the EGR quantity is already


When the substitute value limit is reached, the EGR

system is switched off and the engine power output is

reduced (by reduction of the injected fuel quantity).

Further interventions in the case of a faulty ECT sensor:

• activation of a limited operation strategy on vehicles

with thermo management (described in this lesson).

• shutting off of the electric PTC booster heater (not

on all versions),

• switching on of the cooling fan,

• turning off of the air conditioning.

Diagnosis

With regard to exhaust gas emissions, the ECT sensor

plays a very important part, as this value has a

significant influence on the injected fuel quantity and

EGR.

Moreover, the ECT sensor signal is used to define the

warm-up cycle.

Monitoring of the ECT sensor consists of three parts:

• Monitoring for short circuit and open circuit,

• Monitoring of the signal for logical temperature

increases,

• Monitoring for plausibility.

Faults in the EGR sensor have serious effects on the

exhaust gas emissions. Therefore, this is a MIL active

component.


P0117, P0118, P0119.

CHT sensor (1.8L Duratorq-TDCi(Kent) diesel only)

Function

E70404

NOTE: A CHT sensor that has already been removed

may no longer be used.

The CHT sensor is screwed into the cylinder head and

measures the material temperature.

It replaces the familiar ECT sensor.

By measuring the material temperature, engine

overheating (e.g. through the loss of coolant) is clearly

detected.



At high temperatures, the resolution of the CHT sensor

is not high enough to adequately cover the entire

temperature range from –40 °C to +214 °C. Therefore

the temperature curve is shifted by activating a second

resistor in the PCM.

The resistor is activated at a temperature of:

• 85 °C.

The resistor is deactivated at a temperature of:

• 80 °C.

Combined IAT sensor and MAF sensor

Function

E43235

1

2

MAF sensor1

Mark showing installation direction2

Depending on the version, two different MAF sensors

are used:

• analog MAF sensor – transmits an analog voltage

signal to the PCM, where an analog/digital converter

converts the signal for further processing.

• digital MAF sensor – an integrated circuit in the

MAF sensor converts the measured signal directly

into a digital signal.

Note: in Emission Standard IV vehicles, a digital MAF

sensor is usually installed.

Location: in the intake manifold, directly behind the air

cleaner.

The MAF sensor measures the air mass drawn into the

engine. The MAF signal is used:

• as a parameter for calculating the quantity to be

injected and the time of injection,

• for controlling the EGR quantity (closed control loop

with EGR valve).

There is a MAF sensor integrated into the IAT sensor

(forms an NTC).

The IAT sensor corrects the MAF signal so that a more

accurate measurement of the air mass can be achieved.

If no separate IAT sensor is installed in the intake

system downstream of the turbocharger, the IAT signal

is used for calculating the turbocharger outlet

temperature. In this version, the calculated value serves

as a correction factor for calculating the air density

downstream of the turbocharger.

Possible consequences of faults (MAF sensor)

If the signal fails, the PCM employs a substitute value,

which is calculated from the engine speed and other

values.

Possible consequences of faults (integrated IATsensor)

In the event of a fault, the PCM performs the

calculations using a substitute value.

Furthermore, if installed, the thermo management

system is controlled via a limited-operation map. If

installed, the electric PTC booster heater is switched

off.



Sensors

Diagnosis (MAF sensor)


• the sensor for short to ground/battery (by means of

a limit range check) and open control loop.

• the logical rise/fall rate of the signal, whereby


contacts).

• for plausibility of the signal (only 1.4L

Duratorq-TDCi (DV) diesel engine, Emission

Standard IV).

During a test cycle, the current maximum and minimum

values are compared over a specified period for the limit

range check.

If a value exceeds/falls below the calibrated range during

this test cycle, the test cycle is deemed to be faulty and

a test cycle counter is activated.

For a certain number of test cycles, the "sound" and

"faulty" test cycles are recorded, evaluated and

compared with one another.

The ratio of faulty test cycles to the total number of test

cycles is calculated and compared. If the result exceeds

a calibrated limit, a DTC is immediately stored.

The increase check (for intermittent faults) works in a

similar manner.

Malfunctions of the MAF sensor have a significant

influence on exhaust gas emissions if the recirculated

exhaust gas quantity cannot be controlled precisely.

An excessively low EGR quantity causes a dramatic

increase in the NOX emissions, on the other hand an

excessively high EGR quantity causes an increase in

diesel particulate emissions.



• MAF sensor: P0100, P0101, P0102, P0103, P0104.

Diagnosis (integrated IAT sensor)

The monitoring system checks the integrated IAT

sensor:

• for short circuit and open control loop (via the limit

range check),



contacts).

In contrast, the integrated IAT sensor has only a slight

influence on exhaust gas emissions and is therefore non

MIL active.


P0113, P0114.

Vehicle speed signal

Function

The illustration shows the version with ABS

E53694

2

1

3

Wheel speed sensors1

ABS module2

PCM3

There are two methods available for detecting the

vehicle speed:

• Use of a VSS on vehicles with no ABS,

• Via the wheel speed sensors for vehicles with ABS.



The signal from the wheel speed sensors is transmitted

via the CAN data bus. The PCM calculates the vehicle

speed from this.

The vehicle speed signal is used by the PCM to calculate

the gear engaged and as information for the speed

control integrated in the PCM.

For calculation of the vehicle speed, the wheel speeds

of both front wheels are detected and an average value

is calculated.

If one or both front wheel speed signals are faulty, the

signals of both rear wheel speed sensors are used and

their average is taken as the vehicle speed value. If a

fault occurs with the wheel speed sensors (one or both),

a reliable vehicle speed signal can no longer be

transmitted via the CAN data bus.

Effects of faults

Increased idling speed

Uncomfortable juddering when changing gears

Speed control system inoperative (if installed)

Traction control inoperative (if installed)

Reduction of injected fuel quantity

Diagnosis

The vehicle speed signal has only minor effects on

exhaust gas emissions and does not exceed the EOBD

limits.

The vehicle speed signal is, however, part of the freeze

frame data and is therefore classified as MIL active.

Possible diagnostic trouble codes: P0608 (vehicles

with VSS), P0500, U2197 (vehicles with ABS).

APP sensor

E70899

The functioning and fault strategy are very similar to

the APP sensor in the Bosch common rail system (see

relevant section in this Student Information Publication).



Sensors

Vacuum-operated intake manifold flapposition sensor (certain vehicles withemission standard IV)

Function

Figure depicts version of 1.8L Duratorq-TDCi (Kent)

diesel in S-MAX/Galaxy 2006.5 (02/2006-)

E70405

1

2

3




NOTE: The intake manifold flap position sensor is only

installed for certain versions with intake manifold flap.

NOTE: In the 1.8L Duratorq-TDCi (Kent) diesel engine

in the S-MAX/Galaxy 2006.5 (02/2006-) after replacing

the intake manifold flap position sensor an initialization

must be performed with the aid of WDS.

Further improvement of the EGR rate is achieved by

the use of a position sensor on the intake manifold flap.

In vehicles with coated diesel particulate filter the

exact position of the intake manifold flap has an effect

on the active regeneration process (see section on

"Coated diesel particulate filter" in this lesson).

The position sensor is acted on by a reference voltage

(5 V ± 5 %). The analogue output signal to the PCM is

between 5 ... 95 % of the reference voltage.

Effects of faults

Specific EGR is no longer possible.

Diagnosis


• the sensor for short to ground/battery (by means of

a limit range check) and open control loop.


intermittent faults are detected.

Emissions-related component:



Function

The illustration shows the fuel pressure sensor on the fuel

rail of the of the 2.0L Duratorq-TDCi (DW) diesel engine

E43239

1


NOTE: The fuel pressure sensor must on no account

be removed from the fuel rail during servicing.





delivers a voltage signal to the PCM in accordance with


The fuel pressure sensor operates together with the

fuel metering valve and the fuel pressure control

valve on the high pressure pump in a closed control

loop.




• actuate the fuel metering valve on the high pressure

pump and the fuel pressure control valve.

Effects of faults

In the case of a fault, the PCM switches from closed

loop to open loop control and performs a calculation

using an average value (approx. 350 bar), which is made

available via a limited-operation map.

The average value used is within a safe range (in order

to prevent excessive pressure). This means that the

injected fuel quantity and consequently the engine power

output is restricted to a specified limit from approx.

2800 rpm upwards.

Note: For a quick check of the fuel pressure sensor,

disconnect the wiring harness connector while the engine

is running. The engine should run more roughly.

After reconnecting the wiring harness connector, the

engine should return to smooth running.

Diagnosis

The fuel pressure sensor is monitored for the following

functions:

• short circuit, open circuit and open control loop (via

the limit range check),

• logical rise/fall rate of the signal (loose contact

detection)

• sensor-specific signal fluctuations,

• correct pressure reduction after the engine is stopped.

Monitoring of the sensor-specific signal fluctuations

serves to check whether the signal emitted by the sensor

is subject to "normal fluctuations".

A pre-condition for this check is that no faults are

present in the sensor supply voltage and that there is no

short circuit, open circuit or open control loop.

Moreover, the engine must be running in the partial load

range.

During monitoring, the PCM checks whether the signal

fluctuations emitted by the sensor are within a calibrated

minimum limit. If the fluctuations are inferior to the

calibrated minimum limit, a DTC is stored.

This is in order to check whether the sensor is sticking

at a certain point when emitting the signal.

Monitoring for correct pressure reduction is performed

after the engine is switched off using the ignition key

(ignition OFF) as well as if the engine cuts out (ignition

ON or OFF).

The PCM checks for pressure reduction in the high

pressure system.

When the engine is stopped, a timer is activated. The

fuel pressure present at timeout is registered and

compared with the calibrated limit in the PCM. If the

measured value exceeds the calibrated limit, this leads

to a DTC being stored.



Sensors

The substitution strategy is designed so that the EOBD

limits are not exceeded in the case of a fuel pressure

sensor fault. Therefore, this is a non MIL active

component.

In the case of a fault, the engine system fault warning

lamp illuminates.

Typical fault function limits:

• Sensor voltage < 0.19 V (corresponds to approx. 0

bar)

• Sensor voltage > 4.81 V (corresponds to approx.

1800 bar)

• Voltage fluctuations during partial load operation >

0.01 V


P0192, P0193, P0194.

Other sensors

Other sensors include:

• CKP sensor,

• CMP sensor,

• Fuel temperature sensor.

The functioning of these sensors in the engine

management system is similar to that for the Bosch

common rail system (see relevant sections in "Lesson

3 - Bosch common rail system").



Information

The function of the switches listed below is similar to

that in the Bosch common rail system:

• Oil pressure switch,

• Stoplamp switch/BPP switch,

• CPP switch.

See also the relevant sections in the Bosch common rail

system in this Student Information Publication.



Switch

Fuel metering valve

Function

E53949

2

6 5

1

3 4

Electromagnetically operated fuel metering valve1

Piston2

Bush3

Compression spring4

Coil5

Armature6

NOTE: During repair, the fuel metering valve must not

be removed from the high pressure pump. The pump

may only be replaced as a complete unit.

The fuel metering valve is bolted directly onto the high

pressure pump.

Depending on the fuel pressure in the fuel rail, the fuel

metering valve regulates the fuel feed (and consequently

the fuel quantity) from the transfer pump to the high

pressure pump elements.

This permits the fuel quantity supplied to the high

pressure pump to be adapted to the engine requirements

from the low-pressure side. This minimizes the fuel

quantity that flows back to the fuel tank.

In addition, this control function reduces the power

consumption of the high pressure pump. This improves

the efficiency of the engine.

The fuel metering valve is operated electromagnetically

and is closed and opened in a controlled manner via

pulse-width modulated signals from the PCM.


ActuatorsLesson 4 – Siemens-Common RailSystem

The type of pulse width modulation is a function of:

• Driver's requirements,

• Fuel pressure requirement,

• Engine speed.

Function

E53950

1

1

1

3

2

Fuel supply from the transfer pump1

Piston2

Fuel feed from the high pressure pump3

Fuel metering valve not actuated

• When de-energized, the piston closes the passage

between the two ports (1) and (3) by means of

compression spring force. The fuel supply to the

high-pressure pump is interrupted.

E53951

1

1

1

2

6

7543

Fuel supply from the transfer pump1

Piston2

Fuel feed to the high pressure pump3

Coil energized4

Fuel volume5

Control current6

Fuel metering valve characteristic curve at

constant engine speed.7

Fuel metering valve actuated

• The valve coil is energized by the PCM in

accordance with the engine requirements. The

armature force is proportionate to the electrical

control current and acts against the compression

spring via the moving piston.

• The aperture between the two ports (1) and (3) and

consequently the fuel quantity supplied to the high

pressure pump via the port (3) is also proportional

to the control current. This means that the greater

the cross section of the aperture, the greater the fuel

quantity supplied.



Actuators

Effects of faults

NOTE: When de-energized, the fuel metering valve is

closed.


high pressure control valve and the fuel pressure

sensor on the fuel rail in a closed-loop control circuit.

Depending on the extent of the fault, either a limited

operation program is activated, or in the case of serious

faults, the injected fuel quantity is set to 0 (engine cuts

out or does not start).

Diagnosis

In the Siemens strategy, the fuel metering valve, the

fuel pressure control valve as well as the fuel pressure

sensor operate in close interdependency and should

therefore not be treated separately during EOBD fault

analysis. A description of the principle of operation of

these components (fuel metering/fuel pressure control

valve) for the EOBD can be found in the section "Fuel

pressure control valve" in this lesson.

Fuel pressure control valve

E53952

2 3 4 5

6

7

1

Electromagnetically operated fuel pressure

control valve1

Valve seat2

Valve ball3

Coil4

Armature5

Compression spring6

Pin7

NOTE: During repair, the high pressure control valve

may not be removed from the high pressure pump. The

pump may only be replaced as a complete unit.

The fuel pressure control valve is flanged directly onto

the high pressure pump.

The high pressure control valve regulates the fuel

pressure at the high pressure outlet port of the high

pressure pump and consequently the pressure in the fuel

rail. In addition, pressure fluctuations arising during

fuel supply and the injection process are compensated

by the fuel pressure control valve.



The fuel pressure control valve is actuated by the PCM

so that the optimum fuel pressure is present in the fuel

rail for all engine operating states.

The fuel pressure control valve is operated

electromagnetically and is closed and opened in a

controlled manner via pulse-width modulated signals

from the PCM. The variable actuation of the valve is a

function of driver request, fuel pressure requirement

and engine speed.

Function

E53953

2

3

1

2

4

Fuel pressure at the high pressure outlet port of

the high pressure pump1

To fuel return2

Valve ball3

Compression spring (partial section shown)4

Fuel pressure control valve not actuated

• The valve ball is only operated via the spring force.

This maintains a low fuel pressure (pmin) at the high

pressure outlet port of the high pressure pump to the

fuel rail. The fuel pressure control valve is open.

Note: In the case of a defective fuel pressure control

valve (e.g. if the valve is permanently de-energized) a

fuel rail pressure of only 50 bar is achieved during the

starting phase. This holding pressure is a result of the

closing force of the compression spring when the valve

is de-energized.

The required pressure in the fuel rail during starting

must be at least 150 bar. Below this minimum pressure,

fuel injector needle lift is not possible. The engine

cannot be started, it cuts out.



Actuators

E53954

2

3

1

2

5

76

4

8 10

9

Fuel pressure at the high pressure outlet port of

the high pressure pump1

To fuel return2

Valve ball3

Compression spring4

Armature5

Coil energized6

Pin7

High fuel pressure8

Valve control current9

Fuel pressure control valve characteristic curve10

Fuel pressure control valve actuated by PCM

• The energized coil attracts the armature. The

armature transfers the magnetic force to the valve

ball via the pin.

• The force with which the armature is attracted, and

consequently the pressure on the valve ball, is

proportionate to the valve control current. The fuel

pressure control valve closes.

• In the case of maximum PWM actuation, the

maximum required fuel pressure (depending on

actuation of the fuel metering valve) is adjusted in

the fuel rail.

Effects of faults


high pressure control valve and the fuel pressure

sensor at the fuel rail in a closed-loop control circuit.

In the case of serious faults, for example a short or open

circuit, fuel injection no longer takes place as the fuel

pressure is limited to 50 bar owing to the de-energized

fuel pressure control valve.

In the case of various control faults in the PCM, a

limited operation program is activated, permitting

continuation of the journey to the next workshop under

restricted conditions.

Diagnosis (fuel metering valve and fuel pressurecontrol valve)

The EOBD requirement demands the detection of faults

when determining the injected fuel quantity and fuel

injection timing. These parameters can have serious

effects on the exhaust gas emissions.

The determination of the fuel injection timing is

established via the crankshaft position.

The injected fuel quantity results from the engine speed

and the opening time of the fuel injector, depending on

the fuel pressure in the fuel rail.



Monitoring of the fuel pressure is a function determined

by the interaction of the fuel metering valve (adjusts

the delivery quantity for the fuel rail), the fuel pressure

control valve (regulates of the fuel pressure to the fuel

rail) and the fuel pressure sensor (provides feedback

regarding the actual fuel pressure in the fuel rail).

The Siemens diagnostic system classifies faults in the

fuel metering valve either

• as control faults (in this case the fuel pressure is

limited to a safe range) or

• as malfunctions (in this case, the engine is switched

off by the PCM), for example short or open circuit.

The following monitoring is performed in the context

of EOBD:

• Shorts and open circuit (no power consumption at

the relevant valve).

• Power consumption of the fuel metering valve/fuel

pressure control valve or pulse-width modulation

from the PCM outside the limit range. From the

output shape of the pulse width modulated signals,

the monitoring system identifies (by comparing it

with the target map data) whether the actuation is

within the limits. Power consumption of the

respective components provides information to the

PCM as to whether the relevant component is

operating correctly or not.

• Plausibility check for correct closing of the fuel

metering valve.

• Position (actuation) of the fuel metering valve

deviates to an impermissible extent from the position

(actuation) of the fuel pressure control valve.

• Sticking fuel pressure control valve.

• Adjustment of the map data for the fuel metering

valves reaches the maximum (impermissible

deviation of position with regard to map data; in

order to achieve the required fuel pressure, the fuel

metering valve must open to an impermissible

extent).

Whether a fault has relevance to exhaust gas emissions

depends on the type of fault. Both MIL active and non

MIL active faults are therefore possible. Comprehensive

fault strategies decide whether the MIL or only the

engine system fault warning lamp is activated.


P0003, P0004, P0089, P0090, P0091, P0092, P120F.



Actuators

Piezo-electric control of fuel injectors

Operating principle

E54178

1

2

3

A

B

C

D


Voltage pulse from the PCM: Start of charging

phase, fuel injector begins to openB

InjectionC

Voltage pulse from the PCM: Start of discharging

phase, injection endsD

PCM1

Piezo actuator2

Injector needle3

The piezo-electrically controlled fuel injectors switch

up to four times more rapidly than electro-magnetically

actuated fuel injectors.

Actuation of the fuel injectors for fuel metering (start

of injection and injected fuel quantity) is performed

directly by the PCM, whereby the target rail pressure

must be at least 150 bar during startup.

A voltage pulse is required both for opening and closing

the fuel injectors.

The initial charging voltage applied by the PCM for

opening the fuel injectors is 70 V, however, this is

increased to approx. 140 V within 0.2 milliseconds by

the piezoelement. The charging current is approx. 7

A.

The voltage pulse causes the individual peizoelements

to press against one another, generating further voltage.

During the charging phase, the piezo actuator expands

(elastic tension) and opens the fuel injector needle.

In order to end the injection process, a further voltage

impulse is required from the PCM. The discharging time

of the piezo actuator and consequently the closing time

of the fuel injector needle is approx. 0.2 milliseconds.



Fuel injector actuation characteristic curve

E54179

1

A B

4

2

3

Injected fuel quantity for pilot injectionA

Injected fuel quantity for main injectionB

Fuel injector needle lift (mm)1

Actuation current (amps)2

Voltage (V)3

Crankshaft angle (CS degrees)4

The various characteristic curves during pilot injection

and main injection are shown in the illustration.

In the case of vehicles with diesel particulate filters, any

possible post-injections following the main injections

during the regeneration process are comparable to the

pilot injections.

In order to operate the piezo actuator, a brief burst of

current (charging current) is needed.

During the injection phase, a voltage of approx. 140 V

is maintained by the PCM by means of a capacitor.

To reverse the expansion of the piezo actuator, a short

burst of current in the opposite direction (discharging

current) is generated.

The discharging current causes the piezo actuator to

return to its initial position and injection ends.

Note:

• As the injection is ended by means of the discharging

current, the wiring harness connector of the piezo

fuel injectors must on no account be detached when

the engine is running.

• If the wiring harness connector is detached at the

moment of injection, this leads to continuous

injection and engine damage.

Effects of faults



loud combustion noise (e.g. resulting from cut-off of

the pilot injection)


Moreover, electrical faults lead to deactivation of

cylinder balancing and limited anti slip regulation (no

intervention in engine management).

Diagnosis

In the context of EOBD the PCM performs various

electrical checks in the individual fuel injector electrical

circuits.

Electrical faults in the fuel injectors are detected via the

power consumption at the piezo actuator by means of

the relevant output stage in the PCM.


malfunctions using several electrical tests:


• Fuel metering fault of a single fuel injector

This works by monitoring the staged power supply of

the fuel injectors (as described previously).

The power consumption of the piezo actuator (in relation

to a defined time) indicates whether the actuator is

working within its tolerances.



Actuators



injected fuel quantity and the injection timing can no

longer be determined precisely.

This fault is therefore a MIL active fault, unless a fault

of this kind leads to engine shutoff.



Certain faults (e.g. short to positive) lead to the fuel

injectors no longer being actuated.

Possible diagnostic trouble codes: P0200 to P0204;

P0606; P1201 to P1204, P1551 to P1554.

Boost pressure control valve (variablegeometry turbocharger,vacuum-controlled)

Function

The boost pressure control valve is provided with a

vacuum by the vacuum pump.

Pulse-width modulated signals from the PCM control

this vacuum via the boost pressure control valve.

The controlled vacuum acts on the vacuum unit in the

variable geometry turbocharger.

Effects of faults

In the event of a fault, boost pressure control is no longer

possible. Therefore, the injected fuel quantity is limited

(power output reduction) and the EGR system is

deactivated.

Diagnosis

Boost pressure control operates in a closed control loop.

The adjustment of the guide vanes of the variable

geometry turbocharger is carried out via the boost

pressure control valve. The boost pressure is controlled

depending on requirements via the MAP sensor.

Monitoring of the boost pressure control valve

comprises the following checks:

• short circuit (to ground and positive) and open

circuit,

• for intermittent faults (for example loose contact),

Furthermore, boost pressure control valve or vacuum

system faults are detected by the MAP sensor.

Boost pressure control valve faults are detected by the

output stage in the PCM via the power consumption of

the boost pressure control valve.

As the EGR system is deactivated, the NOX emissions

increase sharply. As a result, EOBD limits are exceeded.



P0048, P2263



Electrical turbocharger guide vaneadjustment actuator

E62583

1

2


actuator1

Actuator lever2

At the time of going to press, installed in the 1.8L

Duratorq-TDCi (Kent) diesel engine only.

The purpose and internal functioning are similar to

the installed actuator in the Delphi common rail system

(see relevant section in "Lesson 2 – Delphi common rail

system").

However, the type of control differs. Two types are

used in the Siemens common rail system:

• Actuation of the actuator unit via a separate line,

• Complete regulation by the PCM.

Actuation via a separate line

E62584

2

1


actuator1

PCM2

The actuator is activated by PWM signals via separate

wiring through the PCM.

The actuator control unit then activates the servo motor

accordingly. The position sensor detects the current

position of the guide vanes and communicates this

position to the actuator control unit.

Effects of faults

Boost pressure control is no longer possible in the event

of turbocharger guide vane adjustment actuator

malfunctions. In this case, the engine output is restricted

by means of a reduction in the injected fuel quantity.

An implausible boost pressure is detected by the MAP

sensor, and the turbocharger guide vane adjustment

actuator then sets the guide vanes to the fully open

position.

In case of a fault, the EGR system is switched off.

Diagnosis

The monitoring system of the turbocharger guide vane

adjustment actuator consists of direct and indirect

monitoring.



Actuators

Direct monitoring:

• Monitoring of the PCM/actuator wiring for short

circuits to ground and positive.

• The integrated diagnosis in the control unit of the

actuator detects malfunctions in the actuator and

PWM as well as voltage supply outside the standard

range.

Indirect monitoring:

• Indirect monitoring is performed via the MAP sensor.

In the process, the engine management system checks

whether the currently required boost pressure is

actually being provided.

• An open circuit (open control loop) in the signal wire

from the PCM to the actuator cannot be detected by

the PCM. However, an open circuit leads to an

implausible boost pressure which then results in the

guide vanes of the turbocharger being set in the fully

open position (minimal boost pressure). The pressure

deviation is detected by the MAP sensor and a

relevant DTC is stored.

It is therefore a MIL active component.

Complete regulation by the PCM.

See relevant section in "Lesson 5 – Denso common rail

system".

Intake manifold flap and intakemanifold flap solenoid valve(vacuum-operated systems)

Function

E54180

1 23

5

4

Air flow in intake manifold1


PCM3


Vacuum unit5

In some versions, a vacuum-operated intake manifold

flap is used, which is actuated via an intake manifold

flap solenoid valve.

The intake manifold flap has the following functions:

• Preventing "serious engine judder" when the engine

is stopped,

• Closing the air channel through the intercooler

(vehicles with fuel additive diesel particulate

filter),

• Restricting the intake air to improve the EGR rate

(certain vehicles with emission standard IV).

• Restricting the intake air to assist the increase in

exhaust gas temperature during the active

regeneration process (vehicles with coated diesel

particulate filter). For information on this see section

on "Coated diesel particulate filter" in this lesson.



Preventing "serious engine judder" when the engine

is stopped:

• Diesel engines have a high compression ratio. The

high compression pressure of the intake air affects

the crankshaft via the pistons and connecting rods

and causes judder when the engine is stopped.

• The intake manifold flap solenoid valve connects

the vacuum for the intake manifold flap vacuum unit,

as a result of which the intake manifold flap is

closed. This prevents engine judder when the engine

is stopped.

• The intake manifold flap solenoid valve is energized

when the engine is stopped. The vacuum for

actuation of the intake manifold flap vacuum unit is

activated and the intake manifold flap is closed

briefly.

Closing the air channel through the intercooler

(vehicles with fuel additive diesel particulate filter):

• This function is utilized when the exhaust gas

temperatures are low in vehicles with diesel

particulate filters. The intake manifold flap closes

the air channel through the intercooler at the same

time as the intercooler bypass is opened (see relevant

section in this brochure).

An additional function in other versions is that the air

intake is restricted for better exhaust recirculation at

low engine speeds.

Restricting the intake air to improve the EGRrate (certain vehicles with emission standardIV)

With certain vehicles, the normal exhaust gas

recirculation is not adequate to return the required EGR

rate.

By slightly restricting the intake air using an intake

manifold flap, a vacuum is created in the intake tract.

This vacuum increases the EGR flow.

Effects of faults

In the event of a signal failure or a failure of the intake

manifold flap solenoid valve:

• the intake manifold flap remains open when the

engine is stopped. This results in increased engine

judder when the engine is stopped.

• controlled Exhaust Gas Recirculation is only

possible to a limited extent.

• the regeneration of the diesel particulate filter

cannot be performed in an ideal way under certain

conditions.

Diagnosis

The intake manifold flap solenoid valve is checked for

short circuit and open circuit in the context of EOBD.

Faults can be classified as either MIL active or non

MIL active (depending on the function of the

component in the strategy).

Intake manifold flap servo motor (1.4LDuratorq-TDCi (DV) diesel engine,emission standard IV)

Function

E54183

Some engine versions with emission standard IV

(without diesel particulate filter) are equipped with

an intake manifold flap servo motor.



Actuators

In these versions the intake manifold flap only serves

to restrict the intake air for more efficient exhaust gas

recirculation (more efficient exhaust gas recirculation

at lower engine speed/load ranges).

If the system does not provide a sufficient quantity of

exhaust gas at low engine speeds/loads despite a

fully-opened EGR valve, the intake manifold flap is

closed by a specified value.

The resulting low pressure causes more of the exhaust

gases to be drawn away from the EGR valve. In this

way, the EGR is adjusted to the required amount.

The current setting of the intake manifold flap is

determined by the MAF sensor (closed control loop).

Effects of faults

Intake manifold flap servo motor faults lead to the EGR

system being switched off.

Diagnosis

Based on the power consumption of the servo motor,

the PCM detects whether actuation is within the limits.

In this manner, the system detects a short or open circuit.

Since the EGR system is deactivated in the event of a

fault, this is a MIL active component.

EGR valve solenoid valve(vacuum-controlled systems)

Function

The EGR valve solenoid valve is actuated via PWM

signals from the PCM, in accordance with the required

exhaust gas quantity to be recirculated.

The duty cycle with which the EGR valve solenoid valve

is actuated by the PCM therefore determines the

appropriate vacuum level for actuation of the EGR valve

and consequently of the EGR quantity.

Effects of faults

In case of a fault, the EGR system is switched off.

Note: If the EGR valve is sticking in the open position,

incomplete combustion occurs at high engine speeds

due to a lack of oxygen. This results in increased black

smoke formation and rough running.

Diagnosis

Exhaust gas recirculation via the EGR valve solenoid

valve operates in conjunction with the MAF sensor, in

a closed loop control circuit.

The EGR valve solenoid valve is monitored for short

circuit and open circuit by the output stage in the PCM

(via the power consumption of the solenoid valve).


P0406



EGR valve (electrically controlledsystems)

Function

E54181

A

B

Installation position on 1.4L Duratorq-TDCi

(DV) diesel engine (Emission Standard IV)A

Installation position on 2.0L Duratorq-TDCi

(DW) diesel engineB

Depending on the engine version, an electrically

controlled EGR valve is used in the Siemens Common

Rail system.

This EGR valve comprises the following components:

• Servo motor,


• the EGR valve itself.

Exhaust gas recirculation is further optimized by means

of the electrically controlled EGR valve, which has a

positive effect on exhaust gas emissions.

With the introduction of Emission Standard IV, an

electrically controlled EGR valve is installed in all

versions.

The illustration shows an excerpt of the circuit diagram

of the 2.0L Duratorq-TDCi (DW) diesel engine

E54182

4

2

1

3

1

PCM1

DC motor2

Servo motor3

Position sensor4

NOTE: Following replacement of the EGR valve or

replacement/reprogramming of the PCM, the EGR valve

must be initialized by the PCM via WDS.

The servo motor acts as a DC motor that sets the

requested opening cross-section of the EGR valve.

Actuation is by means of the PCM via pulse width

modulation.

The exact position of the EGR valve is determined via

the position sensor.



Actuators

It is therefore a closed-loop control circuit.

Note: Each time the engine is stopped, a

cleaning/adaptation mode is activated by the PCM,

whereby the EGR valve is moved from its fully open

position to a completely closed position (by means of

maximum activation of the DC motor).

However, the longer the engine is in operation, the

greater the likelihood of residues forming on the valve

seat of the EGR valve as a result of the exhaust gases

flowing past it. These residues can cause the mechanical

closing point of the EGR valve to shift.

For this reason, the closing point is reconfigured each

time the engine is stopped. Consequently, the position

sensor maintains its ability to perform precise

measurement after long periods of operation.

Note: In some versions cleaning/adaptation mode can

be observed with the help of a WDS datalogger.

Effects of faults

In the event of a fault, controlled exhaust gas

recirculation is no longer possible and the EGR system

is switched off. If the EGR sticks open, this is detected

by the position sensor and the PCM then reduces the

quantity of fuel injected and thus engine performance.

Diagnosis

Monitoring of the EGR servo motor is divided into three

monitoring operations:

• Monitoring of the DC motor,

• Monitoring of the position sensor,

• Monitoring of the EGR valve.

In addition, the entire EGR system (interaction between

the EGR valve, position sensor, servo motor and MAF

sensor) is monitored under certain operating conditions.

The DC motor is monitored for the following:

• Power consumption of the motor (excessively high

or low current flow through the coil).

• Cleaning diagnosis of the EGR valve

The power consumption of the coil is used as a basis

to check whether the signal from the PCM is within the

limits. Moreover, potential overheating of the EGR

valve is detected via the resistance of the coil.

Cleaning diagnosis is also performed via the power

consumption of the DC motor. During cleaning, the DC

motor must open and close the EGR valve within a

defined timeframe. A sticking EGR valve is detected

via the power consumption of the motor.

The position sensor is monitored for the following:

• limit range check: detects short and open circuits.

• logical rise/fall rate of the signal: by this means,

intermittent errors (e.g. loose connector contact) are

determined.

• plausibility check: detects a seized or sticking EGR

valve

The plausibility check is started when a certain engine

speed is reached.

If a control deviation of more than +20 % or –30 % with

regard to the calibrated values is detected during the

check, this is interpreted as a fault by the PCM and a

relevant DTC is stored.


Possible diagnostic trouble codes (DC motor): P0403,

P0404, P1193.

Possible diagnostic trouble codes (position sensor):

P0403, P0404, P0405, P0406, P0409, P0489, P0490,

P1335, P1409, P141A.



Note

The engine warm-up regulation is implemented for

vehicles that were built up to January 2005.

Component locations

E53945

1

2

3

4

5

6

78

910

Coolant pump1

EGR cooler2

Heater core3

Thermostat housing4


Thermostat6

Shutoff solenoid valve7

Radiator8

Oil/coolant heat exchanger9

Coolant reservoir10



Engine warm-up regulation(only 2.0LDuratorq-TDCi (DW) diesel engine)

Some versions with Siemens common rail system are

equipped with an engine warm-up regulator.

This regulator permits faster warming up of the engine

and reduces the increased pollutant emissions during

the warm-up phase.

A bypass solenoid valve has been integrated in the

coolant system for this purpose.

Like the ECT sensor, the bypass solenoid valve is

located in the thermostat housing.

Actuation of the bypass solenoid valve is via the PCM,

which performs regulation in accordance with the

coolant temperature signal.

A conventional thermostat, which works according to

the expanding material principle, is also used for engine

temperature regulation.

Another component is the shutoff solenoid valve. This

limits the flow of coolant to the coolant expansion tank

during the warm-up phase.

Note:

• in January 2004 the PCM software was changed.

This modification to the software (starting with

software bearing the suffix NB) meant that the

shutoff solenoid valve is no longer controlled. From

March 2004, production with the shutoff solenoid

valve ceased altogether.

• For this reason the shutoff solenoid valve is no longer

covered in the following function description.

Principle of operation

First phase

E53946

1

2


Thermostat2

In the first phase, the bypass solenoid valve and the

thermostat are closed.

The coolant is fed by the coolant pump through the

engine and the oil cooler directly to the heat exchanger.

It is then returned to the coolant pump via the EGR

cooler.




Second phase

E53947

1

2


Thermostat2

Above a certain coolant temperature, the bypass solenoid

valve begins to open and remains open until engine

operating temperature is reached.

Part of the coolant now flows directly back to the

coolant pump while the remainder is routed via the heat

exchanger.

The thermostat remains closed.

Third phase

E53948

1

2


Thermostat2

When the thermostat opening temperature is reached,

the thermostat opens.

At the same time, the bypass solenoid valve is closed.

Coolant is now also routed through the radiator (large

coolant circuit).

Values

Power supply voltage of bypass solenoid valve approx.

12 V.




Effects of faults

In the case of a fault, the cooling fan runs at maximum

power. The air conditioning system is also switched off,

or switching on the air conditioning system is disabled.

Diagnosis

The bypass solenoid valve is only monitored for short

and open circuit. In this way, a blocked solenoid valve

(open or closed state) can be detected by the PCM.

If a "control circuit fault - low" is detected, the PCM

interprets this as a short to ground or an open control

loop.

If a "control circuit fault - high" is detected, the PCM

interprets this as a short to positive.

Bypass solenoid valve faults have no effect on exhaust

gas emissions. Therefore, this is a non MIL active

component.


• P2682 (short to ground / open control loop),

• P2683 (short to positive).





The illustration shows boost pressure control on the 2.0L Duratorq-TDCi (DW) diesel engine

E56065

2

1

3

5

67

4

Boost pressure solenoid valve1

MAP sensor2

Intercooler3

Vacuum unit for variable turbine geometry (with

turbocharger position sensor)4

Turbocharger(s)5

PCM6

Vacuum pump7

On a variable turbocharger, the boost pressure is

regulated by adjusting the guide vanes. This means that

optimum boost pressure can be set for any operating

condition.

The actual value of the boost pressure is measured by

the MAP sensor and in some versions by the

turbocharger position sensor as well. The set value

depends on the speed and injected fuel quantity as well

as the BARO.

When a control deviation occurs, the guide vanes of the

variable-geometry turbocharger are adjusted via the

boost pressure control solenoid valve.



metering system.



Turbocharger diagnosis

Boost pressure control works as a system. The

interaction of individual components (including the

turbocharger) is monitored.

Malfunctions of the turbocharger and faults of the boost

pressure control solenoid valve or the vacuum system

for the turbocharger actuation result in increased exhaust

emissions which exceed the EOBD limits. Certain faults

also lead to the EGR system being switched off.

Therefore, this is a MIL active system.

Malfunctions in the boost pressure control system are

detected by the MAP sensor.

In the event of a fault, the PCM limits the injected fuel

quantity (power output reduction) and sets a diagnostic

trouble code.


E70775

PCM1

High pressure pump2

High pressure chambers for high pressure

generation3

Fuel feed4


Fuel pressure control valve6


Fuel rail8

Solenoid valve9

Injector needle10






Via the high pressure chambers of the common rail

high-pressure pump, fuel is compressed and fed to the

fuel rail.






condition.


fuel combustion.




The fuel pressure sensor continuously informs the PCM

about the current fuel pressure.

Precise regulation of the fuel pressure is performed via

the fuel pressure control valve.

The fuel pressure supplied to the fuel rail is dependent

on the engine speed and engine load.




In the case of fully electronic engine management this

is achieved by the PCM specifying injected quantity

= 0. The fuel injector piezo elements are therefore no

longer actuated and the engine is switched off.


After the engine has been switched off, pressure is

released through leakage in the injection pump and the

fuel injectors. For safety reasons, however, a certain

period of time has to elapse before the high-pressure

system is opened after the engine is stopped (see current

Service Literature).

Other strategies

The following additional strategies are similar to those

for the Delphi common rail system (see relevant sections

in "Lesson 2 – Delphi common rail system"):

• Idle speed stabilization,

• Surge dampers,

• Smooth-running control (cylinder balancing),

• External fuel quantity intervention.

The following additional strategies are similar to those

for the Bosch common rail system (see relevant sections

in "Lesson 3 – Bosch common rail system"):

• Regeneration process (vehicles with diesel particulate

filter and fuel additive),

• EGR system.



Note

The diesel particulate filter system with fuel additive is

essentially similar to that of the Bosch common rail

system (see relevant section in "Lesson 3 – Bosch

common rail system")

Only the differences are discussed in the following

section.

Component overview

9

10

1112

65

E48491

13

4

14

2

13

7

8





sensor1


particulate filter2


Pipes to diesel particulate filter differential

pressure sensor4

Instrument cluster5

Fuel-additive control unit6

Tank flap switch7

Tank flap solenoid8

Fuel additive tank9


Fuel injector11

Fuel tank12

PCM13


sensor14


E54231

Exhaust gas from engine1


Filtered exhaust gas3


Catalytically cleaned exhaust gas5




The diesel particulate filter is designed as a separate

component and is downstream of the oxidation catalytic

converter.

The particulate filter is a honeycomb structure, the walls

of which are made of porous silicon carbide. In addition,

the individual ducts are sealed at one side and offset to

each other.

After combustion has occurred, some diesel particulates

may still be present in the exhaust gas. As part of the

filtration process, the exhaust gases loaded with diesel

particulate matter flow into the diesel particulate filter

and are then forced to flow through the porous walls as

a result of the staggered position of the sealed channels.

The build up of diesel particulate matter in the

intermediate chambers of the porous walls increases the

filtration effect still further.

Intercooler bypass

E54232




Connecting piece between air cleaner housing

and turbocharger1

Combined IAT and MAF sensor2

Intercooler3

Connecting piece between turbocharger and

intercooler4

Intercooler bypass5

Intercooler bypass flap vacuum unit6

Intake manifold flap housing7

Turbocharger(s)8


Intercooler/intake manifold flap housing

connection10

An intake manifold flap housing has been added to the

intake system in conjunction with the particulate filter

system. The intake manifold flap housing contains the

following components:

• Intercooler bypass flap with vacuum unit,

• Intake manifold flap with vacuum unit,

• MAP sensor,

• IAT sensor (not illustrated).

The intake manifold flap creates the connection

between the cooled air from the intercooler and the

intake ports of the engine via the intake manifold flap

housing.

The intercooler bypass valve creates a direct

connection between the compressor side of the

turbocharger and the intake ports of the engine via the

intake manifold flap housing. The intercooler is

bypassed.

Actuation of the two flaps is performed by vacuum,

which is controlled by means of two solenoid valves.

During the regeneration phase the air mass flowing

through the intercooler (regulated by the intake manifold

flap) is reduced.

At the same time, the flow of uncooled air mass via the

intercooler bypass (regulated by the intercooler bypass

flap) is increased.

This reduces the engine's cylinder charge while keeping

the intake air temperatures constant to prevent variations

in exhaust gas temperatures during regeneration.

The position of both valves is dependent on the intake

air temperature. For this reason, there is an additional

IAT sensor in the intake manifold flap housing,

downstream of the intake manifold flap and intercooler

bypass flap (not illustrated).




Component overview – system control

E70774


sensor1


particulate filter2


sensor3

IAT sensor4

Fuel tank flap switch and solenoid (in the tank

flap)5

Piezo sensor on fuel additive pump unit6

Fuel-additive control unit7

PCM8




CAN9

DLC10

Intercooler bypass flap solenoid valve11


Fuel additive pump13


When replacing a PCM or before loading a new software

as well as replacing the diesel particulate filter, always

read the instructions in the current Service Literature.

Exhaust gas temperature sensors

Function

E54235


sensor1



particulate filter3





The exhaust system of the 2.0L Duratorq-TDCi (DW)

diesel engine incorporates a catalytic converter exhaust

gas temperature sensor and a diesel particulate filter

exhaust gas temperature sensor.

The exhaust gas temperature of at least 500°C to 550°C

required for the oxidation of the diesel particulates is

detected by the exhaust gas temperature sensors and


The exhaust gas temperature input parameters are used

for calculation purposes by the PCM, which also takes

other parameters into account.



can be initiated.

Through the arrangement of the two exhaust gas

temperature sensors, the exhaust gas temperature

required for regeneration can be adjusted and monitored

very precisely.

The regeneration process cannot be terminated unless

a minimum temperature of 450 °C is reached and

maintained.

Effects of faults

If a fault occurs at one of the two exhaust gas

temperature sensors, the value of the other exhaust gas

temperature sensor is used by the PCM.

If both exhaust gas temperature sensors are faulty, a

substitute value is calculated based on the coolant

temperature, engine load and engine speed.

Diagnosis

The following checks are carried out:

• short and open circuit (by means of a limit range

check).

• logical rise/fall rate of the signal, whereby


contacts),

• plausibility (following engine staring, a certain

temperature increase is expected by the PCM).

A faulty exhaust gas temperature sensor has no direct

influence on exhaust emissions. As regeneration is

however significantly impaired, and clogging of the

diesel particulate filter is possible, the MIL is actuated

in the case of a fault. Therefore, they are MIL active

components.

Possible diagnostic trouble codes (catalytic converter

exhaust gas temperature sensor): P0425, P0426,

P0427, P0428, P2080.

Possible diagnostic trouble codes (diesel particulate

filter exhaust gas temperature sensor): P0435, P0436,

P0437, P0438, P042A, P042B, P141E, P2084, P042C,

P042D.




Intake manifold flap and intercooler bypass flap solenoid valves

Function

E54236


Intercooler bypass flap vacuum unit2


Intercooler bypass flap solenoid valve4

PCM5

The intake manifold flap has another function in

addition to restricting the intake air for exhaust gas

recirculation and closing the intake system when the

engine is stopped.

During the regeneration phase, the intake manifold flap

closes off the air flow via the intercooler, depending on

requirements. At the same time, the uncooled charge

air is fed via the intercooler bypass flap.

Adjustment of the intake manifold flap is performed by

the intake manifold flap solenoid valve via vacuum.

During the regeneration phase, the intercooler bypass

flap opens, enabling uncooled charge air to be directed

to the combustion chambers.

The uncooled air prevents cooling of the combustion

chamber at low engine speeds/engine loads and this

promotes the regeneration of the diesel particulate filter.

Adjustment of the intercooler bypass flap is performed

by the intercooler bypass flap solenoid valve via

vacuum.

In accordance with the requirements, the solenoid valves

are actuated at a specified duty cycle by the PCM.

Effects of faults

If a fault occurs at one (or both) of the two solenoid

valves, limited regeneration is still possible, depending

upon how high the intake air temperature is and the

operating condition of the engine.

Diagnosis

In the context of EOBD both solenoid valves are

monitored for short and open circuit.




Faults to the solenoid valves have very little effect on

exhaust gas emissions. Therefore, they are non MIL

active components.

Possible diagnostic trouble codes (intake manifold

flap solenoid valve): P0488, P0489, P0490.

Possible diagnostic trouble codes (intercooler bypass

flap solenoid valve): P0033, P0034, P0035.




Overview – diesel particulate filter

E70406

7

1 2

3

4

5

6


Flexible pipe2

Location of exhaust gas temperature sensor –

diesel particulate filter3


Rear pipe – diesel particulate filter differential

pressure sensor5

Front pipe – diesel particulate filter differential

pressure sensor6

Location of exhaust gas temperature sensor –

catalytic converter7

With the launch of the S-MAX/Galaxy 2006.5

(02/2006-) a coated diesel particulate filter is used in

conjunction with the 2.0L Duratorq-TDCi (DW) diesel

engine.

The function is similar to the coated diesel particulate

filter in the Delphi common rail system (see relevant

section in "Lesson 2 – Delphi common rail system" in

this brochure).




Emission control components

E70407

1

3

4

5

6

7 8

9

10

2


sensor1


sensor2


sensor3

MAP sensor4


PCM6

CAN7

DLC8


Fuel injector10

Note: The function of the components in the system is

similar to that of the diesel particulate filter in the Delphi

common rail system (see relevant section in "Lesson 2

- Delphi common rail system" in this brochure).


The coated diesel particulate filter is built in the vehicle

for life. It therefore has no maintenance intervals.

However, if it is necessary to replace the diesel

particulate filter, it is essential that the instructions in

the current Service Literature are followed.

Before replacing the PCM or before loading a new

software as well as replacing the diesel particulate filter

differential pressure sensor, always read the instructions



Coated diesel particulate filterLesson 4 – Siemens-Common RailSystem


After replacing the intake manifold flap position sensor

or after replacing/reprogramming the PCM, an

initialization of the intake manifold flap position sensor

must be performed using the PCM (see information in

the current Service Literature).

Intake manifold flap, intake manifoldflap position sensor and intake manifoldflap solenoid valve

Function

E70408

1 2 3 4

MAP sensor1

IAT sensor2



The figure depicts the installation position of the intake

manifold flap, the vacuum unit and the intake manifold

flap position sensor.

The function of the intake manifold flap during the

active regeneration process is similar to that of the diesel

particulate filter in the Delphi common rail system (see

relevant section in "Lesson 2 – Delphi common rail

system" in this Student Information Publication).

Note: After replacing the intake manifold flap position

sensor or after replacing/reprogramming the PCM, an

initialization of the intake manifold flap position sensor

must be performed using the PCM (see information in

the current Service Literature).




Overview

E53588

78

6

4

F

A

BC

D

E

12

3

5

Fuel feedA

High pressure lineB

Fuel injection lineC

Fuel return from high-pressure pumpD

Leak-off pipeE

Fuel return to fuel tankF

High pressure pump1

Fuel rail2

Fuel injector3

Fuel return collector pipe4


Fuel filter6


Siemens systemLesson 4 – Siemens-Common RailSystem

Fuel tank7 Fuel level sensor unit8

General

Function



pressure pump.





Leak-off fuel from the fuel injectors and/or returning

fuel from the high pressure pump are fed back into the

fuel tank.



bending.










Irregular idling







refueled.







Siemens system

Fuel filter

Function

Fuel filter of the 1.4L Duratorq-TDCi (DV) diesel engine

E53589

1

2

3

5

4

Fuel feed port (from fuel tank)1

Fuel feed port (to high pressure pump)2

Fuel filter with water separator3

Water drain screw4


Different fuel filters are used for the Siemens common

rail System depending on the type of engine. Their

operating principles and service-relevant characteristics,

however, are very similar.

Both fuel filters are equipped with a water separator,

which must be drained regularly in accordance with the

specified service intervals.

For this purpose, open the water drain screw on the filter

housing and allow approx. 80 to 100 ml of liquid to

drain into an appropriate container. Then tightly close

the water drain screw again and dispose of the liquid.

Both fuel filters also featured a fuel heater, which is

activated at low temperatures.

Fuel filter of the 2.0L Duratorq-TDCi (DW) diesel engine

E43236

1 2

3

4

Fuel feed port (from fuel tank)1

Fuel feed port (to high pressure pump)2


Water drain screw4

Fuel pre-heating is controlled by a bi-metallic strip and

functions independently of the PCM.

The bi-metallic strip controlled fuel pre-heater is

activated when the ignition is on (ignition key in

position II) regardless of whether the engine is running

or not.

Regardless of the ambient temperature, the bi-metallic

strip closes the circuit and the heating element in the

fuel pre-heater is activated.

• In the 1.4L Duratorq-TDCi the on/off temperature

for the heating element is approximately 5°C.

• In the 2.0L Duratorq-TDCi (DW) diesel engine the

heating element is switched on at –2°C ± 2°C and

switched off at +3°C ± 2°C.






filter.

Note: a certain quantity of air is drawn out of the fuel

tank together with the fuel when the transfer pump draws

fuel into the high-pressure pump. The air bubbles are

very small, however, and cannot initially be seen with

the naked eye.

The air bubbles are separated out in the fuel filter and

clump together to form larger bubbles. These air bubbles

occasionally emerge from the filter material and are

drawn into the high pressure pump. They can be seen

through a transparent hose. This form of separation is

entirely normal.

The visual inspection for air bubbles in the transparent

hose is therefore not counted as a fault diagnosis.

Effects of faults


Irregular idling




Manual pump

E53599

1

A

63

54

3

2

Direction of travelA


Manual pump2

Hand pump bypass line3

Fuel feed line to high pressure pump4

Fuel return line from high pressure pump5

Fuel feed line from fuel tank6

Some versions with Siemens common rail system are

equipped with a rubber hand pump. This is for bleeding

the fuel pipes prior to initial operation of the vehicle or

may be used during repair work.

With the hand pump, fuel can be pumped from the fuel

tank via the fuel filter to immediately before the high

pressure pump port.



Siemens system

Due to the installation position of the hand pump in the

bypass line between the fuel feed and return lines, the

normal flow of fuel through the high pressure pump is

bypassed.

This arrangement prevents the hand pump from

interfering with the normal fuel flow through the high

pressure pump. It also ensures that the fuel can be

extracted as close to the high pressure pump port as

possible when bleeding the system following repair or

maintenance work.

For vehicles that are not equipped with a hand pump,

the special tool for bleeding the system must be used.

High-pressure system – general

The illustration shows the high pressure system of the 2.0L Duratorq-TDCi (DW) diesel engine

E43283

1

2

34

56

Fuel injector1



High pressure pump4

Fuel rail5




High pressure pump

Overview

The illustration shows the high pressure pump with drive shaft for timing belt drive (1.4L Duratorq-TDCi (DV) diesel

engine)

E53590

1

5

6

23

A

B

C

4

Fuel returnA

High-pressure connectionB

Fuel feedC

Fuel metering valve (partial view)1

High pressure pump element (displacement unit)2


Eccentric4

Drive shaft5

Transfer pump6

Note: Depending on the engine version, the high

pressure pump is driven via the timing belt for camshaft

drive (1.4L Duratorq-TDCi (DV) diesel engine) or via

the exhaust camshaft (2.0L Duratorq-TDCi (DW) diesel

engine). The design and function of the high-pressure

pump are essentially similar.

Function of the high-pressure pump





the vehicle.



Siemens system

First, the fuel is drawn from the tank by the transfer

pump integrated in the high pressure pump and delivered

to the high pressure pump.

The high-pressure pump permanently generates the

high system pressure for the fuel rail. Therefore, the

compressed fuel does not have to be supplied under high

pressure for each injection process individually, unlike

systems with distributor type injection pumps.

The high pressure chambers are formed by three pump

elements (displacement units), each offset by 120

degrees.

The fuel metering valve and the fuel pressure control

valve are bolted/flanged to the high pressure pump

housing. These ensure optimum control of the high

pressure for the system.

Due to the permanently high system pressure, injection

quality is optimized over the entire engine speed/load

range.



High pressure generation and fuel routing in the high pressure pump

E53591

1

10

13

14

11

9

10

10

11

11

12

1313

4

B

D

8

A

C3

2

5

7 6

Fuel feedA

Fuel feed (fuel quantity fed to the high pressure

pump)B

High pressure connection to the fuel railC

Fuel returnD

Admission-pressure control valve1

Screen filter2

Intake side of transfer pump3

Transfer pump4



Fluid filter7



Siemens system

High pressure pump8

Eccentric on drive shaft9

Pump element inlet valve10

Pump element outlet valve11

High-pressure ring line12

High pressure pump elements13

Lubrication valve14



pressure pump.

The transfer pump delivers the fuel on to the fuel

metering valve and to the lubrication valve. When the

fuel metering valve is closed, the admission pressure

control valve opens and routes the excess fuel back to

the inlet side of the transfer pump.

The lubrication valve is calibrated in order to always

ensure sufficient lubrication and cooling in the interior

of the pump.

The fuel quantity fed to the high pressure chambers

(pump elements) is determined via the

electromagnetically operated fuel metering valve

(actuated by the PCM).

The fuel pressure control valve is located in the high

pressure channel, between the high pressure chambers

and the high pressure outlet port to the fuel rail. This

electro-magnetically operated valve, which is actuated

by the PCM controls the fuel pressure which is fed into

the fuel rail via the high pressure outlet port.

The fuel pressure control valve routes the excess fuel

into the fuel return line and back to the fuel tank.

Principle of high pressure generation (intake stroke)

E53592

1

1

5

4

3

2

A B

C2

3

4

5

D

Fuel intakeA

Fuel deliveryB

Fuel feed from fuel metering valveC

Fuel delivery to high pressure ring lineD

Inlet valve1

Outlet valve2

Piston3



Drive shaft4 Eccentric5

The three pump plungers are actuated by the rotary

movement of the high pressure pump drive shaft and

the eccentric on the shaft.

When the fuel metering valve opens the inlet to the high

pressure chambers, the pressurized fuel from the transfer

pump is fed to the inlet valves at the high pressure

chambers. If the transfer pressure exceeds the internal

pressure of the high pressure chamber (pump plunger

in TDC position), the inlet valve opens.

Fuel is now forced into the high-pressure chamber,

which moves the pump plunger downwards (intake

stroke).

Principle of high pressure generation (deliverystroke)

When the pump plunger passes BDC, the inlet valve

closes due to the increasing pressure in the high pressure

chamber. The fuel in the high-pressure chamber can no

longer escape.

As soon as the pressure in the high pressure chamber

exceeds the pressure in the high pressure channel, the

outlet valve opens and the fuel is forced into the high

pressure channel (delivery stroke).

The pump plunger delivers fuel until TDC is reached.

The pressure then drops and the outlet valve closes.

The pressure on the remaining fuel is reduced. The pump

plunger moves downwards.

If the pressure in the high-pressure chamber falls below

the transfer pressure, the inlet valve reopens and the

process starts again.

Fuel rail (common rail) and highpressure fuel lines

Fuel rail

The illustration shows the system in the 2.0L

Duratorq-TDCi (DW) diesel engine

E53593

2

34

1

High pressure fuel lines (to the fuel injectors)1

High pressure pump line (to high pressure pump)2

Fuel rail3






Pressure fluctuations are induced in the high pressure

fuel system due to the operating movements of the high

pressure chambers in the high pressure pump and the

opening and closing of the fuel injectors.



Siemens system

The fuel rail is therefore designed in such a way that its

volume is sufficient, on the one hand, to minimize

pressure fluctuations. On the other hand, the volume

in the fuel rail is small enough to build up the required

fuel pressure for a quick start in the shortest possible

time.

The fuel supplied by the high pressure pump flows via

a high pressure line to the fuel rail (high pressure

accumulator). The fuel is then delivered to the individual

fuel injectors via the four injector tubes which are all

the same length.



constant.


NOTE: The fuel pressure sensor must not be removed

from the fuel rail during servicing. If the fuel pressure

sensor is faulty the fuel rail must be replaced along with

the fuel pressure sensor.

In order that the engine management system can

determine the injected fuel quantity precisely, as a

function of current fuel pressure in the fuel rail, a fuel

pressure sensor is located on the fuel rail (see lesson 3).

High pressure fuel lines









fuel injectors.



Fuel injectors

E53594

1

7

6

89

104

11

6

7

23

1

E

D

C

2

3

4

5

6

A B

E

D

C

Fuel injector (1.4L Duratorq-TDCi (DV) diesel

engine and 1.8L Duratorq-TDCi (Kent) diesel

engine)

A

Fuel injector (2.0L Duratorq-TDCi (DW) diesel

engine)B

Fuel injector headC

Hydraulic servo systemD

Fuel injector nozzleE

Connector for PCM1

Piezo actuator2


Copper sealing ring4

Emission standard coding5

Fuel return port6

Retainer7

Fuel return adapter8

O-ring seal9

Adapter fastening clip10

Plastic bush11

Depending on the engine version, fuel injectors of

different designs are used. Their basic construction and

function are however largely the same.

The start of injection and the injection quantity specified

by the PCM are implemented by means of the

piezo-electrically controlled fuel injectors.



Siemens system

Depending on engine speed and engine load, the fuel

injectors are actuated by the PCM with an opening

voltage of approximately 70 V. The piezo effect causes

the voltage within the piezo element to rise to

approximately 140 V.

The fuel injectors inject the appropriate fuel quantity

for all engine operating conditions into the combustion

chambers in accordance with the combustion cycle.

Extremely short switching times of approximately 200

µs permit extremely rapid reaction to changes in the

operating conditions. The fuel quantity to be injected

can thus be metered very precisely.

The fuel injectors are divided into three assemblies:

• fuel injector head, including the piezo actuator,

• hydraulic servo system,

• fuel injector nozzle.

NOTE: In the case of repairs, the fuel injectors cannot

be dismantled, as this results in their destruction.

NOTE: The wiring harness connectors of the piezo fuel

injectors must on no account be detached when the

engine is running. The piezo actuators remain expanded

for a certain period after the power is interrupted, i.e.

the fuel injectors remain open. Effect: Continuous

injection and engine damage!

The copper sealing rings must be replaced during

servicing.

Special features

1.4L Duratorq-TDCi (DV) diesel engine:

• In newer versions, a distinction is made between

Emission Standard III and Emission Standard IV

fuel injectors. A code is stamped onto the fuel

injector shaft for this purpose:

– E3 = Emission Standard III,

– E4 = Emission Standard IV.

2.0L Duratorq-TDCi (DW) diesel engine:

• A guide bushing located in the lower part of the

cylinder head and a plastic bushing on the fuel

injector shaft serve to fasten the fuel injector.





E53595

4

3

2

1

8

2

6

3 35

7

High pressure feed line1

Control piston2

Fuel return3

Piezo actuator4

Valve mushroom5

Control chamber6

Nozzle prechamber7

Injector needle8

The fuel is fed at high pressure from the fuel rail via the

high pressure feed line into the control chamber and the

nozzle prechamber.

The piezo actuator is de-energized and the orifice for

fuel return is closed by means of the spring-loaded

mushroom valve.

The hydraulic force now exerted onto the fuel injector

needle by the high fuel pressure in the control chamber

via the control piston is greater than the hydraulic force

acting on the fuel injector needle, as the surface of the

control piston in the control chamber is greater than the

surface of the fuel injector needle in the nozzle

prechamber.

The needle of the fuel injector is closed (no injection).



Siemens system

Fuel injector opens

E53596

3

6

2

8

1

4

3

2

7

9

5

9

High pressure feed line1

Control piston2

Fuel return3

Piezo actuator4

Valve mushroom5

Control chamber6

Nozzle prechamber7

Injector needle8

Valve piston9

The piezo actuator, which is energized by the PCM,

expands (charging phase) and pushes against the fuel

injector piston.

The mushroom valve opens the orifice which connects

the control chamber with the fuel return line.

This results in a pressure drop in the control chamber

and the hydraulic force acting on the fuel injector needle

is now greater than the force acting on the control piston

in the control chamber.

This causes the fuel injector needle to be moved

upwards, the fuel injector opens and the fuel enters the

combustion chamber via the spray holes.

At a certain point, the piezo actuator is deactivated by

the PCM. The fuel injector piston moves back upwards

and the mushroom valve closes off the control chamber.

As soon as the pressure in the control chamber exceeds

the pressure in the nozzle prechamber, the fuel injector

needle closes off the spray holes and injection ends.



Fuel injector identification markings

E53597fedc

b

a

Identification number coding:

a. Classification (only 2.0L Duratorq-TDCi (DW)

diesel engine

b. Ford part number

c. Year of manufacture (C = 2003, D = 2004). . . )

d. Month (A = January, B = February, ... . . L =

December)

e. Day (01 ... 31)

f. Part number (00001 ... 99999)

The identification markings of the piezo fuel injectors

are located on the fuel injector head.

During production, the piezo fuel injectors are

manufactured without tolerances and consequently

have no identification number for the purpose of

adaptation to the PCM using the WDS.

Classification:

• The fuel injectors for the 2.0L Duratorq-TDCi

(DW) diesel engine are marked with a number for

classification purposes.

• A total of three classifications are available:

– 4, 5 and 6

• When replacing one fuel injector, it should be noted

which classification is marked on the fuel injector.

• All the fuel injectors installed in an engine must have

the same classification!

When replacing all fuel injectors, the new fuel injectors

may have a different classification, For example, if the

old fuel injectors are in class "5" and the new ones are

all class "4", this is permissible.

The change of classification must nevertheless be

communicated to the PCM using WDS.



Fuel injector leaks


needles

Irregular idling



Siemens system


1. Which components are used for controlling fuel pressure?

a. Fuel pressure sensor, fuel metering valve and MAP sensor

b. Fuel pressure sensor, fuel metering valve and fuel pressure control valve

c. Fuel pressure sensor, fuel metering valve and ECT sensor

d. Fuel temperature sensor and fuel metering valve

2. Which of the following statements is true?

a. The fuel metering valve is set to a limited-operation position when de-energized.

b. The fuel metering valve is fully open when de-energized.

c. The fuel metering valve is fully closed when de-energized.

d. The position of the fuel metering valve is detected by a position sensor.

3. Detaching the wiring harness plug from the piezo fuel injector when the engine is running.

a. leads irrevocably to destruction of the engine bearings due to the uneven running of the engine.

b. can lead to engine damage.

c. results in a short circuit and thus the destruction of the PCM.

d. is recommended in order to identify a faulty fuel injector.

4. The intake manifold flap

a. is only used for improved engine stopping.

b. is not active during the active regeneration process.

c. may be active during the passive regeneration process.

d. may be active during the active regeneration process.


Test questionsLesson 4 – Siemens-Common RailSystem








ObjectivesLesson 5 – Denso-Common RailSystem

Overview

M

E70317

1

2

3

4

6

5

7

8

9

10

11

12

13

14

15

16

17

18 19

20 21

22

23

24

25

26


Lesson 5 – Denso-Common RailSystem

CHT sensor1

MAPT sensor2

MAF sensor3

APP sensor4

Oil level/temperature sensor (certain versions

only)5

Stoplamp switch6

CKP sensor7

CMP sensor8


VSS (vehicles with no ABS)10


Water-in-fuel sensor (certain markets only)12

GEM13

Electric EGR valve with position sensor14

Ignition lock15

High pressure pump (with fuel metering valve

and fuel temperature sensor)16

PCM (BARO sensor integrated into the control

unit)17

CAN18

DLC19


actuator (certain versions only)20

Fuel injectors21


Cooling fan module23

Cooling fan24



Notes on this lesson

The components of the engine management as well as

their function in the system are to some extent similar

to those in the Delphi common rail system.

For this reason, only the new or modified components

and functions are discussed in this lesson.

Components/functions which are not discussed here in

detail can be found in "Lesson 2 - Delphi common rail

system".

Characteristics

The following components originate from the Denso

company:

• High pressure pump (with fuel metering valve and

fuel temperature sensor),

• Fuel rail (with fuel pressure sensor and pressure

limiting valve),

• Fuel injectors.

The engine management is performed by a Visteon

PCM.




Fuel injectors

A 16-digit identification number is engraved on every




of WDS.






Calibrating the high-pressure pump (fuelmetering valve)

After replacing the high pressure pump and/or the PCM

the fuel metering valve of the high pressure pump must

be calibrated with the aid of WDS.

High pressure system leak test

After working on the high-pressure system (e.g. after

replacing a fuel injector or after replacing the high

pressure pump or the injector tubes) a high-pressure

system leak test must be conducted with the aid of WDS.

Fuel filter with water-in-fuel sensor (certainmarkets only)

After replacing the fuel filter, a parameter reset for the

values of the water-in-fuel sensor must be carried out

with the aid of WDS.

PCM

E70318

Connector C1(A) with 32 PINC1

Connector C2(B) with 48 PINC2

Connector C3(C) with 32 PINC3

The PCM is the main component of the engine



them and calculates the signals for the actuators (for

example fuel injectors, boost pressure control valve,

EGR valve, etc.).






a processing unit.

Note: The further "function" is similar to that for the


"Lesson 2").

Diagnosis

The PCM performs self-monitoring to ensure correct

operation. Malfunctions in the hardware or software of

the PCM are displayed by means of a DTC. Additional

monitoring (see below) is also performed.




– In the case of reference voltage monitoring, so-called

comparators compare the individual reference

voltages for the relevant sensors programmed in the

PCM to check if they are within limits.

– If a set reference voltage of 5 V falls below 4.7 V, a

fault is stored and the engine is stopped.



• The engine adjustment data and freeze frame data

are stored in the EEPROM.

• The freeze frame data forms part of the EOBD. Fault

entries are detected appropriately and indicated by

a DTC.

Vehicles with EOBD


• Since the engine is stopped in the event of a fault,

this is non MIL active monitoring.



• Faults are MIL active, as the freeze frame data forms

part of the EOBD.



MAF sensor

Function

E70320

The MAF sensor works according to the hot film

principle.

The sensor's output signal is a digital square-wave signal

with a variable frequency.

The following generally applies: the frequency drops

with increasing engine speed.

The MAF sensor is used to control the exhaust gas

recirculation (closed-loop control).

Effects of faults

In the event of a fault, the EGR system is switched off.

Diagnosis


• if the values output by the sensor are within the

limits,

• the sensor for short circuit to battery/ground,

• for intermittent faults.

Emissions-related component:

• Yes (MIL-active).

APP sensor

Function

For safety reasons, the APP sensor is designed as a

breakerless double sensor.

E70321

1 2

3

PCM1

Gateway (GEM)2

APP sensor3

In this system, the signal from APP sensor 1 is

transmitted directly as a Pulse Width Modulation

signal to the PCM.

The APP sensor 2 signal is transmitted as an analog

signal to the GEM.

In the GEM the APP 2 signal is digitized, then put onto

the CAN data bus and transferred to the PCM.

Effects of faults

If APP sensor 2 fails, the engine runs with decreased

acceleration. However, it is still possible to achieve top

speed.

If APP sensor 1 or the entire APP sensor system fails,

the engine is regulated to an increased idling speed after

the BPP switch and the stoplamp switch have been

actuated once and a plausibility check has been carried

out. It is possible to continue driving but with greatly

reduced power output.



Sensors

Oil level/temperature sensor

E64597

1

23

Oil level/temperature sensor1

Openings2

Oil dipstick3

The 135 PS version of the 2.4l Duratorq-TDCi in the

Transit 2006.5 (at the time of going to press) is equipped

with an oil level/temperature sensor.

The quality of the engine oil is calculated using this

sensor and a strategy implemented in the PCM. This

measure is also able to increase the oil change intervals

in this version.

Furthermore, the driver receives an indication via the

driver information system when the engine oil level has

dropped below the limit.


SensorsLesson 5 – Denso-Common RailSystem

Function

E70772

Electrical connector1

Wire loop2

Temperature sensor (NTC)3

Oil level/temperature sensor4

The oil level/temperature sensor comprises a wire loop,

which is immersed in the engine oil to a greater or lesser

extent corresponding to the oil level.

At the time of the oil level measurement, a regulator

circuit in the PCM closes the circuit of the wire loop.

The regulator circuit regulates a constant current flow

of 195 mA through the wire loop.

The constant current flow heats the wire loop in a

specific way.

The voltage drop (U0) across the wire loop is measured

immediately after the circuit closes. Another

measurement (U1) takes place approximately 1.75

seconds later.

Between the first measurement (U0) and the second

measurement (U1) there is a temperature drop at the

wire loop. It is dependent on the extent to which the

wire loop is immersed in the engine oil.

The temperature drop results from the dissipation of

heat from the wire loop to the engine oil. This

temperature drop causes a change in resistance of the

wire loop and thus also a change in the voltage drop.

The voltage drop is used by the PCM as an indicator

for calculating the oil level and the oil quality.

The integral temperature sensor measures the current

engine oil temperature and is used as a correction factor

for the oil level calculation.

Prerequisites for the measurement

Two conditions must be satisfied in order to ensure the

measurement is correct:

• The engine must be stopped for a certain period of

time (the planned period is up to two minutes –

detailed information was not available at the time of

going to press). This provides an adequate return

flow of engine oil into the oil pan. In this time, the

power supply of the PCM is maintained (Power

Latch Phase).

• The vehicle must be standing on a horizontal surface.

After completing the second measurement, the PCM

calculates the oil level. The calculated value is stored.



Sensors

Strategy for determining a horizontal surface

E70773

3

4

1

2

Reference voltageVref

Signal to the GEMS

Instrument cluster1

PCM2

GEM3

Fuel pump and level indicator module4

In order to ensure a correct measurement of the oil level,

the strategy of the PCM must be certain that the vehicle

is standing on a horizontal surface. It assumes that the

pump area of a filling station has this type of surface.

For this purpose, the signal from the fuel pump and level

indicator module is used.

If, following "ignition ON", the fuel level is significantly

higher than at the last "ignition OFF", the PCM assumes

that the vehicle is at a filling station and, therefore, is

standing on a level surface.

The last oil level measurement, that was stored at the

last "ignition OFF", is classified as a valid

measurement.

Only this oil level measurement is used for the

calculation.

Registering an oil level that is too low

If the PCM has detected refilling of the vehicle fuel

tank, the last oil level measurement is compared with

the map data.

If the measured values indicate an oil level which is too

low, a corresponding indicator/text message is displayed

on the message center.

The indicator/text message illuminates/appears

immediately after "ignition ON" and remains active

until the next "ignition OFF".

For the next "ignition ON" the lamp/text message is

then no longer active.

Note: Even if the engine oil has not been topped up, the

indicator/text message is not active again.

Calculation of the oil quality

A strategy is implemented in the PCM that calculates

the optimal time for an oil change.

This calculation is based on the continuous detection of

the engine operating conditions as well as the last valid

oil level measurement.

If this data reveals an oil change is necessary, then this

is indicated via an indicator/text message in the

instrument cluster.

Note: After every oil change, the parameters for the oil

quality calculation must be reset (see the current Service

Literature).


SensorsLesson 5 – Denso-Common RailSystem

Electrical turbocharger guide vaneadjustment actuator

Function

E70322

1

2


actuator1

Variable geometry turbocharger2

In this system, a simplified electrical turbocharger guide

vane adjustment actuator is used.

The integral electronics in the actuator unit are no longer

required.

This means

• that the DC motor is actuated directly by the PCM.

• that the position of the guide vanes is detected

directly via the position sensor by the PCM.

E70323

Connection 1: DC motor (+)1

Connection 2: DC motor (–)2

Connection 3: Position sensor (–)3

Connection 4: PWM position sensor output

signal4

Connection 5: Position sensor reference voltage5

PCM6

DC motor7

Position sensor (breakerless)8


actuator9

The inductive (breakerless) position sensor transmits

PWM signals to the PCM. The duty cycle is determined

by the position of the guide vanes.

Duty cycle of the position sensor:

• with minimum opening of the guide vanes

(maximum boost pressure): approx. 90 %

• with maximum opening of the guide vanes

(minimum boost pressure): approx. 10 %



Actuators

Fuel metering valve

E70324

A

a b

B

1 1

2 23 3

Fuel metering valve opened to maximumA

Fuel metering valve opened to minimumB

VoltageV

Low duty cyclea

High duty cycleb

Transfer pump1


Fuel flow to the high-pressure chambers3

Function

NOTE: The fuel metering valve operates together with

the fuel pressure sensor (on the fuel rail) in a closed

control loop.

NOTE: The fuel metering valve is fully open when

de-energized.

The fuel quantity that passes to the high pressure

chambers of the high pressure pump is dependent on

the opening cross section of the fuel metering valve.

The opening cross-section is determined by the PCM

via the duty cycle of the PWM signal:

• Low duty cycle: large aperture cross-section

• High duty cycle: small aperture cross-section

Effects of faults

In the event of malfunctions: Injected quantity = 0

(engine cuts out or cannot be started.)

Diagnosis


• the circuit for short circuits and open circuit.

• the fuel metering valve for correct function; the

values of the fuel pressure sensor are used for this

purpose. The currently measured values from the

fuel pressure sensor are continuously compared with

the map data. Slight deviations are indicated as

control faults whereupon:


ActuatorsLesson 5 – Denso-Common RailSystem

– the quantity of fuel injected is reduced and

– the pilot injection is deactivated.

• whether serious deviations exist. They are indicated

as a malfunction whereupon

– the quantity injected is set to 0 and the engine is

stopped.

Note: Control faults do not necessarily mean a defective

fuel metering valve or a defective high pressure pump.

A blocked fuel low pressure system or defective fuel

injectors could (among other things) also be the cause.


• Yes (MIL-active), with control faults

• No (Non MIL active), with malfunctions.


Function

E70325

1

2

3

4

PCM1

Coil2

Solenoid armature3

Solenoid valve4



PCM.

Current is applied to the solenoid valves in two stages.

At the beginning of an injection process, the solenoid

valve is actuated with a higher pick-up current so that

it opens quickly.

After a short period of time, the pick-up current is

reduced to a low holding current.

Effects of faults




reduced power output

Diagnosis


malfunctions via several electrical tests.


• Fuel metering fault of a single fuel injector.

The PCM detects malfunctions based on the power

consumption of the solenoid valves.



injected quantity and the injection timing cannot be

determined exactly (see Possible consequences of

faults).



Components significant for emissions:

• Yes (MIL-active), if engine continues to run.

• No (Non MIL active), if the engine is stopped.



Actuators

Overview

E69808

1 2

34

5

8

6

B

A

F

E

7

C

D

Fuel return from high-pressure pumpA

High pressure lineB

Fuel injection lineC

Leak-off pipeD

Fuel return to fuel tankE

Fuel feedF

High pressure pump1

Fuel rail2

Fuel injector3

Pressure limiting valve4

T-piece5

Fuel tank6


Fuel systemLesson 5 – Denso-Common RailSystem

Fuel pump and filling level sensor unit7 Fuel filter8

General

Function



pressure pump.





Oil leaking from the fuel injectors and/or returning fuel

from the high pressure pump are fed back into the fuel

tank.



bending.










Irregular idling







refueled.

Diagnostic information: If the system causes the engine

to judder because the fuel tank is empty, the EOBD is

deactivated during this phase. This prevents apparent

faults from being displayed.

Fuel filter

Function

E69908

2

3

4

5

6

8

7

1

Fuel return (to the fuel filter)1

Fuel return (to the fuel tank)2

Fuel feed (to the high-pressure pump)3

Air cleaner element minder gauge4

Water-in-fuel sensor (certain markets only)5

Water drain screw6

Water-in-fuel sensor wiring harness7

Fuel feed (from the fuel tank)8



Fuel system

The fuel heater functions in a similar way to that in the


"Lesson 2 – Delphi common rail system") via a bi-metal

controlled control valve.

Fuel filter with water-in-fuel sensor (certainmarkets only)

After replacing the fuel filter, a parameter reset for the

values of the water-in-fuel sensor must be carried out

with the aid of WDS.




The illustration shows the system in the 2.4L Duratorq-TDCi

E69809

1

2

3 4

5

6

7

8

9

10

11

High pressure line1

Leak-off pipe2


Fuel injector4


Fuel rail6






Fuel system

High pressure pump10 Fuel return11

High-pressure line and injector tubes









fuel injectors.


The fuel pressure sensor must not be replaced separately

in the event of a fault. The whole fuel rail must always

be replaced in the event of a fault.

Fuel injectors

When replacing one (or more) fuel injector(s) this must

be signaled to the PCM through the input of a 16-digit

code. This code is located in the head area of the fuel

injector.

High pressure system leak test

After working on the high-pressure system (e.g. after

replacing a fuel injector or after replacing the high

pressure pump or the injector tubes) a high-pressure

system leak test must be conducted with the aid of WDS.



High pressure pump

The diagram shows the high pressure pump in the 2.4L Duratorq-TDCi

E69909

6

7

8

9

C

10

1112

13

B

A

1

14

2 34

5

High pressure fuel to fuel railA

Fuel returnB

Fuel feedC

High-pressure chamber outlet valve1

High-pressure chamber inlet valve2

Pump plunger3

Fuel metering valve return spring4


Pre-pressurize control valve (pump interior

pressure)6

Transfer pump (rotor pump)7

Fuel inlet8

Fuel filter9

Eccentric cam ring10

Eccentric cam11

Drive shaft12

Fuel tank13

Overflow throttle valve14



Fuel system

Design





the vehicle.

Low-pressure zone:

• The transfer pump draws fuel out of the fuel tank

via the fuel inlet.

• The pump internal pressure is adjusted via the

admission-pressure control valve. This ensures that

sufficient lubrication and cooling are always

provided for the high pressure pump components.

Excess fuel is transferred to the inlet side of the

transfer pump via the admission-pressure control

valve.

• A portion of the fuel is transferred to the fuel

metering valve from the transfer pump. The fuel

quantity delivered to the high pressure chambers is

determined by the opening cross-section of the fuel

metering valve.

• The small restriction bore in the overflow throttle

valve provides for automatic bleeding of the high

pressure pump. The entire low-pressure system is

designed to allow a defined quantity of fuel to flow

back into the fuel tank via the overflow throttle valve.

This assists cooling of the high pressure pump.

High-pressure zone:

– A total of two high pressure chambers, each with

one pump plunger, are used for high pressure

generation.

– The drive for the pump plungers is via an eccentric

cam, which is in turn driven by the drive shaft

(principle similar to the Bosch common rail system,

see relevant section in this Student Information).

– The high pressure pump permanently generates

the high system pressure for the fuel rail.



Principle of high pressure generation

E69910

1 2

3

4

C

A

6

B

5

Pump plunger 1A

Pump plunger 2B

To fuel railC

Inlet valve1

Outlet valve2

Eccentric cam3

Eccentric cam ring4


Drive shaft6



Fuel system

The rotary movement of the drive shaft is converted to

a reciprocating movement by the eccentric cam. The

eccentric cam ring transfers the reciprocating movement

to the pump plungers.

The pump plungers are offset by 180 degrees. This

means, that during a reciprocating movement, pump

plunger 1 performs exactly the opposite movement to

pump plunger 2.

The eccentric cam produces an "upward" stroke:

• Pump plunger 1 moves in the direction of TDC, thus

compressing the fuel and delivering it to the fuel rail

via the outlet valve. The inlet valve is pressed into

its seat by the delivery pressure.

• Pump plunger 2 is moved by the tension spring force

in the direction of BDC. Due to the high pressure in

the fuel rail, the outlet valve is pressed into its seat.

The pump internal pressure opens the inlet valve and

fuel flows into the high pressure chamber.

The eccentric cam produces a "downward" stroke:

• The process is the reverse to that previously

described.

Calibrating the high-pressure pump (fuelmetering valve)

After replacing the high pressure pump and/or the PCM

the fuel metering valve of the high pressure pump must

be calibrated with the aid of WDS.


Structure and task

E69911

1

2

3



Fuel rail3




Pressure fluctuations are induced in the high-pressure

fuel system due to the operating movements in the

high-pressure chambers of the high-pressure pump and

the opening and closing of the solenoid valves on the

fuel injectors.

Consequently, the fuel rail is designed in such a way

that, on the one hand, it possesses sufficient volume to

minimize pressure fluctuations, but, on the other hand,

the volume in the fuel rail is sufficiently low to build

up the fuel pressure required for a quick start in the

shortest time possible.

Function



accumulator. The fuel is then sent to the individual fuel

injectors via the four injector tubes which are all the

same length.





constant.

Pressure limiting valve

The pressure limiting valve opens at a fuel pressure of

approx. 2000 bar. It serves as a safety device in the case

of malfunctions in the high-pressure system. Thus,

damage due to excessive pressure in the high-pressure

system is prevented.

The pressure limiting valve operates as a disposable

valve. This means that it must be replaced after a

single triggering, as the valve can no longer be

guaranteed leak-free.

Triggering of the pressure limiting valve is detected by

the PCM, whereupon a corresponding DTC is set and

the MIL is actuated.

For removal and installation, please follow the

instructions in the current service literature.

Fuel injectors

E69912

A

B

C

1

3

2

Fuel injector nozzleA

Hydraulic servo systemB

Solenoid valveC

Combustion chamber seal1



NOTE: The combustion chamber sealing rings must

not be reused.

The exact procedure for the correct installation of

the fuel injectors can be found in the current service

literature.

Start of injection and injected fuel quantity are adjusted

via the fuel injectors.

In order to achieve the optimal injection timing and

precise injected fuel quantity, special fuel injectors with

a hydraulic servo system and electrical actuator unit

(solenoid valve) are used.

The injectors are actuated directly by the PCM.

The PCM specifies the injected quantity and the

injection timing.


blocks:

• injector nozzle,

• hydraulic servo system,

• solenoid valve.


The operating principle of the fuel injectors is similar

to that of the fuel injectors in the Bosch common rail

system (see relevant section in this Student Information).



Fuel system


Illustration shows top view of fuel injector

E69913

1

3

2


16-digit identification number2

Connection - leak-off pipe3





identification number, which is located on the housing


To ensure optimum fuel metering, the PCM must be

informed of a change of injector.

Furthermore, once new PCM software has been loaded

via WDS, the fuel injectors must also be configured.

This is achieved by entering the 16-digit identification

number into the PCM using the WDS, taking into

account the relevant cylinder.



• Increased black smoke formation,

• Irregular idling




Fuel injector leaks


needles

Irregular idling




1. Which of the following statements about the oil level/temperature sensor is correct?

a. During engine operation the engine oil level is measured continuously via a wire loop.

b. For a correct measurement, the engine must be running and have reached a temperature of at least 60 °C.

c. For a correct measurement, the engine must have cooled down to a temperature of 40 °C.

d. For a correct measurement, the vehicle must be on a horizontal surface.

2. Which statement regarding the fuel metering valve is incorrect?

a. high duty cycle = small opening cross-section of the fuel metering valve

b. low duty cycle = small opening cross-section of the fuel metering valve

c. In the case of malfunctions, the engine is stopped.

d. The fuel metering valve is fully open when de-energized.

3. The pressure limiting valve

a. regulates the fuel pressure in the fuel rail.

b. must be replaced after being triggered once.

c. reduces the fuel pressure after the engine is stopped.

d. may not be replaced as a separate component.

4. Which of the following statements about the APP sensor is true?

a. PWM signal: The frequency decreases with increasing engine speed.

b. PWM signal: The frequency increases with increasing engine speed.

c. The APP sensor transmits the PWM signal (APP 1) and the analogue signal (APP 2) directly to the PCM,

d. The APP sensor transmits the PWM signal (APP 1) and the analogue signal (APP 2) to the gateway first.



Test questions


1. b

2. c

3. d

4. c

Lesson 2 – Delphi-Common Rail System

1. d

2. b

3. c

4. b

Lesson 3 – Bosch-Common Rail System

1. c

2. c

3. a

4. d

Lesson 4 – Siemens-Common Rail System

1. b

2. c

3. b

4. d

Lesson 5 – Denso-Common Rail System

1. d

2. b

3. b

4. a

269Service Training

Answers to the test questions

Anti-lock Brake SystemABS

Accelerator Pedal PositionAPP

Barometric PressureBARO

Bottom Dead CenterBDC

Brake Pedal PositionBPP

Controller Area NetworkCAN

Cylinder Head TemperatureCHT

Central Junction BoxCJB

Crankshaft PositionCKP

Camshaft PositionCMP

Carbon MonoxideCO

Clutch Pedal PositionCPP

Data Link ConnectorDLC

Diagnostic Trouble CodeDTC

Engine Coolant TemperatureECT

Exhaust Gas RecirculationEGR

European On-board DiagnosticEOBD

Generic Electronic ModuleGEM

HydrocarbonHC

Intake Air TemperatureIAT

Injector Driver ModuleIDM

Knock SensorKS

Mass Air FlowMAF

Manifold Absolute PressureMAP

Manifold Absolute Pressure And

Temperature

MAPT

Malfunction Indicator LampMIL

Oxides Of NitrogenNOX

Negative Temperature CoefficientNTC

Passive Anti-theft SystemPATS

Powertrain Control ModulePCM

Positive Temperature CoefficientPTC

Pulse Width ModulationPWM

Temperature And Manifold Absolute

Pressure

T-MAP

Top Dead CenterTDC

Vehicle Speed SensorVSS

Worldwide Diagnostic SystemWDS

Service Training270

List of Abbreviations

curriculum training

Documents

injection system

bosch common rail system

siemens common rail

denso common rail system

delphi common rail system

fuel injection timing

injection process

data processing system