fuel injection aua,aub,bby,bbz,bky

Service 5

Service Department. Technical Information Printed in Czech RepublicS00.5309.00.20

Workshop ManualFABIA 2000

1.4/55 ; 1.4/74 Engine - Fuel InjectionEdition 08.99Engine code AUA AUB BBY BBZ BKY

Service5

The Workshop Manual is intended only for use within the Organisation Škoda.It is not permitted to pass it on to other persons.

© ŠKODA AUTO a. s.

Printed in Czech RepublicS00.5309.00.20

FABIA 2000 1.4/55 ; 1.4/74 Engine - Fuel Injection

List of SupplementsEdition 06.04S00.5309.04.20

List of Supplements to Workshop Manual

FABIA 2000

1.4/55 ; 1.4/74 Engine - Fuel InjectionEdition 08.99

Supple-ment Edition Subject Article Number

08.99 Basic Edition S00.5309.00.20

1 07.00 Supplement to Basic Edition S00.5309.01.20

2 03.01 Modifications in Rep. Gr. 01 and 24 S00.5309.02.20

3 06.02 Additions to engines with the engine codes BBY, BBZ S00.5309.03.20

4 06.04 Supplement to engines with the engine codes BKY S00.5309.04.20


List of Supplements Edition 06.04S00.5309.04.20


Table of ContentsEdition 06.04S00.5309.04.20

I

Table of Contents

01 – Self-diagnosisSelf-diagnosis I . . . . . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... .............. .....

- Properties of the self-diagnosis ...... .............. ............... ............... .............. .....

- Technical data of self-diagnosis ...... .............. ............... ............... .............. .....

- Meaning of the EPC warning lamp (fault lamp for electric accelerator control -K132-) in the dash panel insert ........ ........ . . . . . .. .............. ............... ............... .............. .....

- Meaning of the exhaust gas warning light -K83- . ............... ............... .............. .....

- Connecting up the vehicle system tester -V.A.G 1552- and selecting the control unit for engine electronics ....... .......... . . . .. .............. ............... ............... .............. .....

- Interrogating and erasing fault memory of engine control unit .............. .............. .....

- Automatic test sequence .............. .............. ............... ............... .............. .....

- Performing actuator diagnosis ........ .............. ............... ............... .............. .....

Self-diagnosis II . . . . . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... .............. .....

- Readiness code .......... ........ . . . . . .. .............. ............... ............... .............. .....

- Reading Readiness Code ............. .............. ............... ............... .............. .....

- Generating readiness code ........... .............. ............... ............... .............. .....

Self-diagnosis III . . . . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... .............. .....

- Fault table, fault codes 16496...17566 ............ ............... ............... .............. .....

Self-diagnosis IV . . . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... . ............. .....

- Fault table, fault codes 17573...18100 ............ ............... ............... .............. .....

Self-diagnosis V . . . . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... .............. .....

- Measured value blocks ................ .............. ............... ............... .............. .....

- Safety measures ......... ........ . . . . . .. .............. ............... ............... . ............. .....

- Reading measured value block ...... .............. ............... ............... .............. .....

- Measured value blocks, display groups 001...006 - Basic functions ....... .............. .....

- Measured value blocks, display groups 010...029 - Ignition .. ............... .............. .....

Self-diagnosis VI . . . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... . ............. .....


- Measured value blocks, display groups 030...049, 099 - Lambda control . .............. .....

Self-diagnosis VII . . . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... . ............. .....


- Measured value blocks, display groups 050...069 - Speed control ......... .............. .....

- Measured value blocks, display groups 070...075 - exhaust gas recirculation ......... .....

- Measured value blocks, display group 100 - readiness code ............... .............. .....

- Measured value blocks, display groups 120...129 - Communication ....... .............. .....

24 – Fuel Formation, InjectionRepairing the injection system . . . . . .. .............. ............... ............... .............. .....

- Installed location overview for engines with the engine codes AUA, AUB .............. .....

- Installed location overview for engines with the engine codes BBY, BBZ, BKY ........ .....

- General notes on the injection system ............ ............... ............... .............. .....

- Removing and installing parts of the injection system ......... ............... .............. .....

- Disassembling and assembling intake manifold ................ ............... .............. .....

- Disassembling and assembling fuel distributor with injectors ............... .............. .....

- Disassembling and assembling the air filter ...... ............... ............... .............. .....

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Table of Contents Edition 06.04S00.5309.04.20

II

- Safety measures ................ . . . . . . . . . . . . . .. .............. ............... ............... ...........

- Rules of cleanliness ............. .... . . . . . . . . . .. .............. ............... ............... ...........

Testing components . . . . . . . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... ...........

- Testing throttle valve control unit ............ .............. ............... ............... ...........

- Testing accelerator pedal position sender .. .............. ............... ............... ...........

- Testing the intake manifold pressure sender ............ ............... ............... ...........

- Testing intake manifold temperature sender ............. ............... ............... ...........

- Testing coolant temperature sender ......... .............. ............... ............... ...........

Testing components I . . . . . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... ...........

- Test engine speed sender ..... ............ . .. .............. ............... ............... ...........

- Testing injection valves ......... ........ . . . . . .. .............. ............... ............... . ..........

- Testing the intake system for tightness (unmetered air) .............. ............... ...........

- Testing intake manifold preheating .......... .............. ............... ............... ...........

- Idle testing ......... ........ . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... ...........

Testing components II . . . . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... ...........

- Test lambda probe heating before catalyst . .............. ............... ............... ...........

- Testing lambda probe and lambda control upstream of catalytic converter ....... ...........

- Test lambda probe heating after catalyst ... .............. ............... ............... ...........

- Testing lambda probe and lambda control after catalyst .............. ............... ...........

- Check lambda probe ageing before catalyst ............. ............... ............... ...........

- Testing the engine operating conditions .... .............. ............... ............... ...........

Engine control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... ...........

- Wiring and Component Test with Test Box V.A.G. 1598/31 .......... ............... ...........

- Testing voltage supply for engine control unit ........... ............... ............... ...........

- Procedure after voltage supply has been interrupted ... ............... ............... ...........

- Replacing engine control unit .. ............. .. .............. ............... ............... ...........

- Coding engine control unit ..... .......... . . . .. .............. ............... ............... ...........

- Adjusting the engine control unit to the throttle valve control unit ... ............... ...........

Testing auxiliary signals . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... ...........

- Testing the speed signal ....... ......... . . . . .. .............. ............... ............... ...........

- Testing signals from/to the air conditioning system ..... ............... ............... ...........

- Test brake light switch -F- and brake pedal switch -F47- ............. ............... ...........

- Testing clutch pedal switch -F36- ............ .............. ............... ............... ...........

- Activating and deactivating cruise control system (CCS) ............. ............... ...........

- Testing CCS ....... ........... . . . . . . . . . . . . . . . . . .. .............. ............... ............... ...........

- Testing gear signal .............. .. . . . . . . . . . . . .. .............. ............... ............... ...........

- Test data bus ..... ............ . . . . . . . . . . . . . . . . .. .............. ............... ............... ...........

28 – Ignition SystemRepairing ignition system . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... ...........

- General notes on the ignition system ....... .............. ............... ............... ...........

- Removing and installing parts of the ignition system for engines with the engine codes AUA, AUB ................. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... ...........

- Removing and installing parts of the ignition system for engines with the engine codes BBZ, BBY, BKY .......... ........ . . . . . . . . . . . . . . . . . . . . .. .............. ............... ............... ...........

- Safety measures ................ . . . . . . . . . . . . . .. .............. ............... ............... ...........

- Testing hall sender .............. ... . . . . . . . . . . .. .............. ............... ............... ...........

- Checking the ignition transformer (for engines with the engine codes AUA, AUB) .........

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Table of ContentsEdition 06.04S00.5309.04.20

III

- Check ignition coils with power output stage (engines with engine codes BBY, BKY, BBZ)

- Testing knock sensor ... ............... .............. ............... ............... .............. .....

- Test combustion misfiring ............. .............. ............... ............... .............. .....

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Table of Contents Edition 06.04S00.5309.04.20

IV


Self-diagnosis IEdition 06.04S00.5309.04.20

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01-1 Self-diagnosis I

Properties of the self-diagnosis

The self-diagnosis monitors only a part of the injection and ignition system. The „Current Flow Diagrams, Fault Finding and Fitting Locations“ binder should always be used for fault finding.

The engine control unit -J537- is equipped with a fault memory.

If malfunctions occur in the monitored sensors or compo-nents, they are stored in the fault memory with indication of the fault type.

The engine control unit analyses the information and dis-tinguishes between the different fault codes ⇒ Fault Ta-ble ⇒ Chapter 01-3 and ⇒ Chapter 01-4, and stores these until the fault memory is erased.

Faults that only occur temporarily (sporadically) are out-put with the suffix „sporadically occurred fault“. On the display these faults are indicated by the suffix „SP“. Pos-sible causes of sporadic faults are e.g. a loose contact or a momentary line interruption. If a sporadic fault no longer occurs within 40 warming-up phases (engine started at a temperature of 50°C and switched off at more than 72 °C), the fault is then automatically erased fom the fault memory.

The stored faults can be read out with the vehicle system tester -V.A.G 1552- using programme card -6.0- and higher version or fault reader -V.A.G 1551- using pro-gramme card -9.0- and higher version or vehicle diagno-sis, measurement and information system -VAS 5051-.

After the fault or faults have been rectified, it is necessary to erase the fault memory ⇒ 01-1 page 5 and also to re-generate the readiness code ⇒ Chapter 01-2.

General information on self-diagnosis is provided in the operating instructions for the diagnostic devices -V.A.G 1551-, -V.A.G 1552- or -VAS 5051-.

Technical data of self-diagnosis

Control unit identification:

The control unit version is displayed when the vehicle system tester -V.A.G 1552- is connected and address word 01 „Engine electronics“ is selected ⇒ 01-1 page 4.

01 – Self-diagnosis

Note

Note


Self-diagnosis I Edition 06.04S00.5309.04.20

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01

Equipment

Functions available when using the vehicle sys-tem tester -V.A.G 1552-

The preconditions for selecting the desired functions are given in the following table.

Engine identification characters AUA, AUB BBY, BBZ BKY

System denomination MARELLI 4LV MARELLI 4MV MARELLI 4TV

Exhaust limits conforming to EU-4, EU-3DDK, EU-2DDK

EU4, EU-3DDK, EU-2DDK

EU4, EU-3DDK, EU-2DDK

Electronic throttle system Yes Yes Yes

Self-diagnosis Yes Yes Yes

Actuator diagnosis Yes Yes Yes

Fault memory Permanent memory1)

1) Independent of voltage supply

Permanent memory1) Permanent memory1)

Memory for initialisation values Volatile memory2)

2) The values are erased if the voltage supply is interrupted.

Volatile memory2) Volatile memory2)

Lambda control 2 probes 2 probes 2 probes

Knock control 1 Knock sensor 1 Knock sensor 1 Knock sensor

Intake manifold change-over No No No

Camshaft adjustment No No No

Boost-pressure control No No No

Secondary air system No No No

Exhaust gas recirculation Yes Yes Yes

Note

Operation Precondition

Function on the vehicle system tester -V.A.G 1552 -

Engine not run-ning, ignition switched on

Engine idling Normal driving

01 Interrogating control unit version yes yes yes

02 Interrogating fault memory yes1)

1) Only to be carried out with the ignition switched on and if the engine does not start (activate starter for at least 6 seconds).

yes yes

03 Actuator diagnosis yes no no

04 Basic setting2)

2) To be carried out after the following operations: replacing of engine control unit, throttle valve control unit, exhaust gas recirculation valve or engine or disconnecting of battery. The air conditioning and the ACF system are automatically switched off in function 04.

yes yes yes

05 Erasing fault memory yes yes yes

06 Ending output yes yes yes

07 Coding control unit yes no no

08 Reading measured value block yes yes yes

15 Reading readiness code yes yes yes



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Meaning of the EPC warning lamp (fault lamp for electric accelerator control -K132-) in the dash panel insert

„EPC“ is the abbreviation of Electronic Power Control, which in German is written Elektronische Motorleistungs-Regelung (E-Gas).

Fitting location of the EPC warning lamp:

If faults are detected on the EPC system during operation of the engine, the dashboard insert switches the EPC warning light on. (These faults are identified in the fault table). There is a simultaneous entry in the fault memory of the engine control unit.

Functional test:

– Switch on ignition: the EPC warning lamp must light up.

If the EPC warning lamp does not light up when the igni-tion is switched on:

– Check the dash panel insert and the EPC warning lamp ⇒ Electrical System; Rep. Gr. 90.

If the EPC warning lamp lights up when the ignition is switched on:

– Start engine and run in idle. The EPC warning lamp should go out after a few seconds.

If the EPC warning lamp does not go out:

– Interrogate fault memory, rectify any faults existing and erase the fault memory ⇒ 01-1 page 5.

Meaning of the exhaust gas warning light -K83-

Only for engines complying with exhaust emission standard EU 4 and EU 3DDK

If the engine control unit detects a fault, this is indicated by the lighting up of the exhaust warning lamp

Fitting location of exhaust warning light:

♦ The exhaust warning light may flash or come on as a steady light. The fault memory must be interrogated whatever happens ⇒ 01-1 page 5.

♦ The warning light flashes: There is a fault, which is likely to damage the catalytic converter in this driving condition. In this driving condition only low perform-ance driving is allowed!

CHECK

S01-0090

S01-0091

CHECK

CHECKNote



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♦ The warning light comes on as a steady light: There is a fault which deteriorates the exhaust gas quality. In-terrogate the engine control or the automatic gearbox fault memory.

♦ If there is a driving behaviour problem or a customer complaint and the exhaust gas warning light does not light up, the fault memory should be interrogated since it also possible that faults are stored there which do not immediately switch on the exhaust gas warning light.

Functional test:

– Switch on ignition: The exhaust warning light must light up.

If the gas warning light does not come on when the igni-tion is switched on:

– Check the dash panel insert and the exhaust gas warning light ⇒ Electrical equipment; Rep. Gr. 90 .

If the gas warning light comes on when the ignition is switched on:

– Start engine and run in idle. The gas warning light must go out after a few seconds.

If the gas warning light does not go out:

– Interrogate fault memory, rectify any faults existing and erase the fault memory ⇒ 01-1 page 5.

Connecting up the vehicle system tester -V.A.G 1552- and selecting the control unit for engine electronics

Special tools, test and measuring equipment and auxiliary items required

♦ Vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3, 3A, 3B oder 3C-.

Test conditions

• Fuses 1, 3, 7, 9, 10, 14, 16, 17, 24, 25, 28, 35, 48, 52, 56 and 61 must be o.k.

• Battery voltage must be at least 11.5 volts.

• Earth connections between engine (at gearbox hous-ing) and body (below battery) o.k.

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Procedure

– Fold back trim panel -1-.

– Connect vehicle system tester -V.A.G 1552- with ap-propriate cable.

– Select address word 01 „Engine electronics“.

The control unit identification number and the coding are shown on the vehicle system tester display, e.g.:

♦ 036906034T = Part No. of the control unit (for current control unit version see spare part cata-logue)89MARELLI 4LV = description of system and version

♦

♦ Coding 00031 = coding of control unit with code ver-sions ⇒ Chapter 24-5

♦ WSC xxxxx = workshop code the -V.A.G 1552-, with which the last coding was performed (WSC 00000 ap-pears provided the factory-entered coding has not been changed)

♦ If the control unit version displayed does not corre-spond to the vehicle, replace the control unit ⇒ Chapter 24-5.

♦ Incorrect coding of the engine control unit results in:

♦ Handling problems (jerky gear change, load change jolts etc.)

♦ Increase in fuel consumption

♦ Increase in pollution

♦ Storage of non-existent faults in fault memory

♦ Impossibility of performing certain functions (lambda control, actuation of activated charcoal filter system, etc.)

Interrogating and erasing fault memory of engine control unit

Interrogate and erase the fault memories of al control units ⇒ 01-1 page 6.


♦ Vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3, 3A, 3B oder 3C-.

1552V.A.G.HELPQOC

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Note



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01

Procedure

– Connect vehicle system tester -V.A.G 1552-. Start en-gine and select address word 01 „Engine electronics“ ⇒ 01-1 page 4.

Only if the engine does not start:

– Operate starter for about 6 seconds. after this do not switch off ignition.

– Select function 02 „Interrogate fault memory“.

The number of stored faults or „No fault recognised“ ap-pears in the display.

If no fault is stored:

– Press key.

If one or several faults are stored:

– Select function 05 „Erase fault memory“.

If the ignition was switched off between „Interrogate fault memory“ and „Erase fault memory“, the fault memory is not erased.

– Select function 06 „End output“ and switch ignition off.

– Rectify the faults displayed by referring to the fault ta-ble ⇒ Chapter 01-3 and ⇒ Chapter 01-4.

– Read out readiness code ⇒ Chap. 01-2. If the fault memory has been erased or if the continuous voltage supply from the engine control unit was interrupted, it is then necessary to re-generate the readiness code.

Automatic test sequence

During testing and installation other control units may also detect faults, e.g. pulled-out connectors. This is why, when the work is concluded, that it is necessary to inter-rogate and erase the fault memory on all control units. For this you must proceed as follows:

– Select address word 00 „Automatic Test Sequence“. The tester -V.A.G 1552- sends all known address words in sequence.

If a control unit responds with its identification, the display will indicate the number of faults in the memory or „No fault detected“.

– Erase the fault memory and then carry out a test drive.

During the test drive the following operating conditions must be fulfilled:

♦ The coolant temperature should rise beyond 80°C.

♦ Once this temperature is reached, the following oper-ating states must be reached several times: Idling, part load, full load, overrun, enrichment.

♦ In case of full load the speed should be increased be-yond 3500 rpm.

X faults detected

Vehicle system test HELPThe fault memory is erased

Note



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– Once again interrogate the fault memories of all the control units with the address word 00 „Automatic test sequence“.



If no fault has been recognized by the self-diagnostic sys-tem proceed with fault finding as specified in the corre-sponding fault table in the „Current Flow Diagrams, Electrical Fault Finding and Fitting Locations“ binder.

Performing actuator diagnosis

With the actuator diagnosis the following parts are acti-vated in the sequence indicated:

1. Throttle valve positioner -V60-

2. Activated charcoal filter system solenoid valve 1 -N80-

3. Exhaust gas recirculation valve -N18-

4. Engine speed sender -G28-1)

5. Fuel pump relay -J17-

6. Engine/air conditioning compressor electrical connection1)


♦ Vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3, 3A, 3B oder 3C-

♦ Test box -V.A.G 1598/31-

♦ Handheld multimeter, e.g. -V.A.G 1715-

♦ Diode test lamp e.g. -V.A.G 1527B-

♦ Measuring tool set e.g. -V.A.G 1594C-

♦ Current flow diagram

Test conditions

• Fuses 1, 3, 7, 9, 10, 14, 16, 17, 24, 25, 28, 35, 48, 52, 56 and 61 must be o.k.

• Battery voltage must be at least 11.5 volts.

• All electrical consumers, e.g. lights and rear window heater, must be switched off.

• Throttle valve drive angle senders -G187- and -G188- o.k

1) Ignore

Note

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♦ The actuator diagnosis can only be carried out when the engine is not running and the ignition is switched on.

♦ The final control diagnosis is aborted when the engine is started or when a moment of momentum is detect-ed.

♦ During the actuator diagnosis the individual actuators remain activated until the next actuator is selected by pressing key .

♦ The actuators are tested acoustically or by touch.

Procedure

– Connect vehicle system tester -V.A.G 1552-. Switch ignition on and select address word 01 „Engine elec-tronics“ ⇒ 01-1 page 4.

– Select function 03 „final control diagnosis“.

Readout on display:

Activate throttle valve positioner -V60-:

– Confirm the entry with key .

Readout on display:

The throttle valve positioner should open and close the throttle valve until the next actuator is activated by press-ing key .

If the throttle valve does not move:

– Test throttle valve positioner ⇒ Chapter 24-2, test throttle valve control unit.

Activate solenoid valve 1 for activated charcoal filter system -N80-:

– Press key.

Readout on display:

The solenoid valve (on right, at suspension strut dome) must continue clicking until the next control element is ac-tuated by pressing the key.

– Detach hose from the activated charcoal filter at the solenoid valve.

– Fit auxiliary hose onto the free connection of the valve.

– Blow into the auxiliary hose during the final control di-agnosis (in the direction of the throttle valve control unit). The valve must open and close.

If the solenoid valve does not click:

– Continue test ⇒ 01-1 page 10.

Note

Vehicle system test Q03 - Actuator diagnosis

Q

Actuator diagnosis ->Throttle valve positioner-V60

Actuator diagnosis ->Sol.valve 1 for act. char.filter -N80



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Activate exhaust gas recirculation valve -N18-:

– Press key.

Readout on display:

The exhaust gas recirculation valve (left engine compart-ment at cylinder head) must click until the next actuator is activated by pressing key.

If the exhaust gas recirculation valve does not click:

– Continue test ⇒ 01-1 page 11.

Engine speed sender -G28-: (Ignore)

– Press key.

Readout on display:

Activate fuel pump relay -J17-:

– Press key.

Readout on display:

The fuel pump relay (on the relay plate) must be activated and deactivated until the next control element is actuated by pressing the key.

During activation of the fuel pump relay the fuel pump should also be heard to run at intervals. The door contact switch must not be actuated during the test.

If the relay does not click:


– Testing fuel pump relay ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Locations.

Engine/air conditioning compressor electrical connection (ignore)

– Press key.

Readout on display:

Actuator diagnosis ->Exhaust gas recirculation valve -N18

Actuator diagnosis ->Engine speed sender -G28

Actuator diagnosis ->Fuel pump relay-J17

Note

Actuator diagnosis ->Engine/air cond.compr.electr.connect.



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01

Continuing test if the activated charcoal filter solenoid valve 1 does not click:

– Unplug 2-pin plug from solenoid valve 1 -N80- -arrow-.

– Connect diode testing lamp to the unplugged plug.

– LED must flash.

The LED flashes:

– Proceed with the final control diagnosis up to the end.

– Switch off ignition.

– Replace solenoid valve 1 -N80-.

The LED does not flash:



– Connect test box -V.A.G 1598/31- to wiring loom to engine control unit ⇒ Chapter 24-5. Do not connect up the engine control unit.

– Check wiring between the test box and the 2-pin plug for interruption according to the Current Flow Dia-gram:

– Line resistance: max. 1.5 Ω

– Additionally check the cable for a short circuit to bat-tery positive and to earth.

Specified value: ∞ Ω.

– Check the cable between 2-pin plug contact 1 and the fuel pump relay -J17- for interruption according to the Current Flow Diagram.


If the lines are not found to be faulty:

– Replace engine control unit ⇒ Chapter 24-5.

S01-0092

Plug contact Test box bush -V.A.G 1598/31-

2 64



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01

Continuing test if the exhaust gas recirculation valve does not click:

– Unplug the 6-pin plug from the exhaust gas recircula-tion valve -N18- -arrow- (on the front left cylinder head).

– Connect up the diode test lamp using adapter cables onto the contacts 1+ 5 of the removed plug connec-tion.

– LED must flash.

The LED flashes:



– Replace the EGR valve -N18- ⇒ 1.4/55; 1.4/74 En-gine - Mechanics; Rep. Gr. 26.

The LED does not flash:



– Connect test box -V.A.G 1598/31- to wiring loom to engine control unit ⇒ Chapter 24-5. Do not connect up the engine control unit.






Specified value: ∞ Ω




5 114



01-1 page 12

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Self-diagnosis IIEdition 06.04S00.5309.04.20

01-2 page 1

01

01-2 Self-diagnosis II

Readiness code

Reading Readiness Code

Operation

The readiness code is an 8-digit numerical code that pro-vides information on the status of the emission-relevant diagnosis.

If the diagnosis for a system (e.g. tank ventilation system) was successfully performed, the relevant position of the numerical code is set from 1 to 0.

This diagnosis is performed at regular intervals during normal driving. If repairs have been done on a system rel-evant for the exhaust gas it is recommended to generate the readiness code as this guarantees that the systems operate according to the specifications. If a fault is detect-ed during the diagnosis it is entered in the fault memory.

The readiness code is erased if the fault memory is erased or if there is an interruption to the voltage supply.


♦ Vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3, 3A, 3B, oder 3C-.

Procedure

– Connect vehicle system tester -V.A.G 1552- and enter address word 01 „Engine electronics“ ⇒ Chap. 01-1.

– Select function 15 „Readiness code“.

If all diagnoses were performed successfully, the display must indicate the following:


If the following readout appears in the display:

One of the available diagnoses cannot be completed suc-cessfully.

– Press key.

– Generate readiness code ⇒ 01-2 page 2.

Meaning of the 8-digit numerical block of the readiness code

Readiness code00000000 - Test complete

Readiness code00101101 - Test not complete

The readiness code is only generated if all the display positions show 0

1 2 3 4 5 6 7 8 Diagnosis function

0 Catalytic converter

0 Catalytic converter heater (no diagnosis at present/always „0“)

0 Activated charcoal filter system

0 Secondary air injection system (no diagnosis at present/always „0“)


Self-diagnosis II Edition 06.04S00.5309.04.20

01-2 page 2

01

Generating readiness code


♦ Vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3, 3A, 3B, oder 3C-.

Test conditions

• Vehicle stationary

• On vehicles with an automatic gearbox the selector le-ver must be in position „P“ or „N“.

• All electrical consumers such as lights and rear win-dow heater switched off

• Intake air temperature must be below 60 °C ⇒ display group 004, display field 4

• Coolant temperature at least 80 °C ⇒ display group 004, display block 3

Procedure

– Connect vehicle system tester -V.A.G 1552-. Start en-gine and select the address word 01 „Engine electron-ics“ ⇒ Chapter 01-1.

Work step 1: Interrogating fault memory

– Select function 02 „Interrogate fault memory“.

The number of stored faults or „No fault recognised“ ap-pears in the display.

If a fault is stored in the memory:

– Rectify the faults displayed by referring to the fault ta-ble:

Fault table ⇒ Chap. 01-3 and ⇒ Chap. 01-4.


– Press key.

Work step 2: Erasing fault memory

– Select function 05 „Erase fault memory“.

0 Air conditioning system (no diagnosis at present/always „0“)

0 Lambda probe

0 Lambda probe heater

0 Exhaust gas recirculation


X faults detected

Vehicle system test ->The fault memory is erased



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♦ The readiness code is reset or erased each time the fault memory is erased.

♦ If the ignition was switched off between „Interrogate fault memory“ and „Erase fault memory“, the fault memory is not erased.

– Press key.

The engine must not be readjusted during the work se-quence.

Work step 3: Activated charcoal filter system diagno-sis

– Select function 04 „Basic setting“ and display group 070.

– Depress neither brake nor clutch pedal.

If the diagnosis is initiated by the engine control unit the display in display field 4 will switch from „Test OFF“ to „Test ON“.

– Leave engine running at idling speed until „TVV o.k.“ is read out in display field 4.

If the display does not occur as described:

– Interrogating fault memory.

– Blip throttle about 3 times and repeat the process.

If the display occurs as described:

– Press key.

Work step 4: Lambda probe-ageing diagnosis (inter-val monitoring)


– Depress accelerator pedal twice above 5000 rpm.

– Maintain speed between 1500...3900 rpm until display in display field 4 switches from „Test OFF“ to „Test ON“.

– Leave engine running at idling speed until „B1-S1 o.k.“ is displayed in display field 4.

– Select function 08 „Read measured value block“ and display group number 030.

– Check operating state of lambda control upstream of catalytic converter (display field 1):

Specified value: 111

– Check operating state of lambda control downstream of catalytic converter (display field 2):


Note

Note

System in basic setting 70 29% 65% 342mbar TEV O.K.

C

System in basic setting 34 1830/min 120 C 0.00s Test OFF

Read measured value block 30 111 110



01-2 page 4

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The 3rd bit in display field 2 is only set to 1 under partial load (2500...4000 rpm).

Meaning of 3-digit numerical block in the display fields 1 and 2:

If the specified values are not reached:

– Interrogate fault memory ⇒ Chapter 01-1.

If the specified values are reached:

Work step 5: Catalyst diagnosis

This diagnosis is only successfully completed if no faults relating to the lambda probes or the activated charcoal fil-ter system exist.

– Select function 04 „initiating basic Setting“ and then display group 046.

– Maintain speed between 2000…3000 rpm until dis-play in display field 4 switches from „Test OFF“ to „Test ON“. Catalytic converter temperature in display field 2 must be at least 300 °C.

– Further maintain speed between 2000...3000 rpm un-til the nominal result of the test „CatB1 o.k“ is dis-played in display field 4.

It may also take a few minutes until the readout is changed from „Test ON“ to „Cat B1 o.k.“




– Press key.

Work step 6: Diagnosis of exhaust gas recirculation system

– Select function 04 „initiating basic Setting“ and then display group 075.

– Depress neither brake nor clutch pedal.

– Briefly blip throttle about 5 times up to max. speed.

Note

Meaning, if display positions = 1

1 2 3

1 Lambda control active (partial load)

1 Lambda probe operational

1 Lambda probe heater switched on

Note

System in basic setting 46 2830/min 328,0 C 0.00s Test OFF

Note

C



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01

If the diagnosis is initiated by the engine control unit the display in display field 4 will switch from „Test OFF“ to „Test ON“.

– Leave engine running at idling speed until „Syst. O.K.“ is displayed in display field 4.

If the display does not occur as described:


If the display occurs as described:


– Read out readiness code ⇒ 01-2 page 1.

System in basic setting 75 4830/min 371mbar 0mbar Test OFF



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Self-diagnosis IIIEdition 06.04S00.5309.04.20

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01

01-3 Self-diagnosis III

Fault table, fault codes 16496...17566

♦ Faults related to the electronic throttle are indicated on the dash panel insert by the fault lamp for the elec-tronic accelerator control „EPC warning lamp“).

♦ Faults related to the exhaust are indicated by the „ex-haust gas warning lamp“ in the dash panel insert.

♦ Explanations regarding fault types (e.g. „open circuit or short-circuit to earth“) ⇒ Operating instructions for the vehicle system tester.

♦ If parts are output as faulty: First test all of the cables and plug connections to these components as well as the earth cables of the system according to the current flow diagram. Only if no fault is detected here should the part be replaced. This applies in particular if faults are shown as „sporadic“ (SP).

♦ Once the fault has been corrected erase the fault memory ⇒ Chapter 01-1 and re-generate the readi-ness code ⇒ Chapter 01-2.

Printer edition e.g.:

16497 P0113 035

Intake manifold temperature sender -G72-

Signal too high

sporadically occurring fault

Explanations:

16497 = fault code

P0113 = Ignore the SAE code that may appear next to the fault code.

035 = fault type as digit

Intake manifold temperature sender -G72- = faulty cur-rent path or fault location

Signal too great = fault type as text

Sporadically occurring fault = fault not always present, e.g. loose contact

Note


Self-diagnosis III Edition 06.04S00.5309.04.20

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01

Readout on -V.A.G 1552- Rectifying fault

16496 Intake manifold temperature sender -G72-1)

Signal too low – Read measured value block, display group 004, dis-play field 4 ⇒ Chapter 01-5

– Inspecting intake manifold temperature sender ⇒ Chap. 24-2

– Replace engine control unit ⇒ Chapter 24-5

16497 Intake manifold temperature sender -G72-1)

Signal too high

16500 Sender for the coolant temper-ature -G62-1)

Implausible signal – Read measured value block, display group 001, dis-play field 2 ⇒ Chapter 01-5

– Check the coolant temperature sender -G62- ⇒ Chapter 24-2



Signal too low – Read measured value block, display group 001, dis-play field 2 ⇒ Chapter 01-5

– Check the coolant temperature sender -G62- ⇒ Chapter 24-2

– Test coolant thermostat ⇒ 1.4/55; 1.4/74 Engine - Mechanical Components; Rep. Gr. 19



Signal too high

16505 Throttle valve potentiometer -G69-1)

Implausible signal – Test throttle valve control unit ⇒ Chapter 24-2


Signal too low


Signal too high

16514 Bank 1 probe 11)

Electrical fault in the cir-cuit

– Testing lambda probe and lambda control upstream of catalytic converter ⇒ Chapter 24-4

– Remove short-circuit or line interruption ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Locations.

16517 Bank 1 probe 1 elect.1)

Signal too low – Testing lambda probe and lambda control upstream of catalytic converter ⇒ Chapter 24-4


No activity – Reading measured value block, display group 030 ⇒ Chap. 01-6

– Reading measured value block, display group 031 ⇒ Chap. 01-6

16519 Bank 1, probe 1

Heating circuit electrical fault




– Test lambda probe heater downstream of catalytic converter ⇒ Chapter 24-4


Voltage too low – Test lambda control before catalytic converter ⇒ Chapter 24-4




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01


Voltage too high – Test lambda probe heater downstream of catalytic converter ⇒ Chapter 24-4

– Test lambda probe after catalytic converter ⇒ Chapter 24-4


No activity


Heating circuit electrical fault

– Test lambda control before catalytic converter ⇒ Chapter 24-4


16554 Bank 1, fuel metering system1)

Malfunction – Check fuel filter with regulating valve ⇒ 1.4/55, 1.4/74 Engine - Mechanics; Rep. Gr. 20

– Testing lambda control before catalyst ⇒ Chapter 24-4




System too lean – Check fuel filter with regulating valve ⇒ 1.4/55, 1.4/74 Engine - Mechanics; Rep. Gr. 20

– Test injection valves ⇒ Chapter 24-3


– Testing lambda probe and lambda control down-stream of catalytic converter ⇒ Chapter 24-4


System too rich – Test injection valves ⇒ Chapter 24-3

– Testing lambda control before catalyst ⇒ Chapter 24-4


– Test lambda control before catalytic converter ⇒ Chapter 24-4

16585 Injector cyl. 1 -N30-2)









16603 Maximum engine speed exceeded

– Rectify any mechanical engine damage

16605 Angle sender 2 for TV drive -G188-1)2)

Implausible signal – Read measured value block, display group 062 ⇒ Chapter 01-7

– Test throttle valve control unit ⇒ Chapter 24-216606 Angle sender 2 for TV drive -G188-1)2)

Signal too low


Signal too high




01-3 page 4

01

16611 Sender for accelerator pedal position -G79-1)2)

Signal too low – Read measured value block, display group 062 ⇒ Chapter 01-7

– Test accelerator pedal position sender ⇒ Chapter 24-216612

Sender for accelerator pedal position -G79-1)2)

Signal too high


Short circuit to positive – Test injection valves ⇒ Chapter 24-3


Short circuit to positive





166841) Combustion misfiring detected


– Test ignition leads and spark plugs ⇒ Chapter 28-1

– Testing ignition transformer with power amplifier ⇒ Chapter 28-1

– Inspecting misfiring detection ⇒ Chapter 28-1

16685 Cylinder 11)

Combustion misfiring detected


16686 Cyl. 21)


16687 Cyl. 31)


16688 Cyl. 41)


16705 Engine speed sender -G28-1)

Implausible signal – Check engine speed sender -G28- ⇒ Chapter 24-3

16706 Engine speed sender -G28-1)

No signal – Remove line interruption or short-circuit ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Locations

– Check engine speed sender -G28- ⇒ Chapter 24-3


16708 Knock control

Malfunction – Inspecting knock sensor ⇒ Chapter 28-1

– Read measured value block 028 ⇒ Chapter 01-5

16709 Knock sensor 1 -G61-


– Inspecting knock sensor ⇒ Chapter 28-1

– Read measured value block 028 ⇒ Chapter 01-516710 Knock sensor 1 -G61-

Implausible signal


Signal too low


Signal too high




01-3 page 5

01

16725 Camshaft position sensor ⇒ sender -G40-1)

Implausible signal – Inspecting hall sender ⇒ Chapter 28-1


Signal too low


Signal too high

16735 Ignition control cyl. 11)

Malfunction – Test combustion misfiring ⇒ Chapter 28-1


Malfunction


Malfunction


Malfunction

16785 Exhaust gas recirculation system1)

Flow rate too low – Test exhaust gas recirculation valve -N18- ⇒ Chapter 01-1, final control diagnosis

– Perform basic setting (measured value block 074 and 075) ⇒ Chapter 01-716786

Exhaust gas recirculation system1)

Flow rate too great

16787 Exhaust gas recirculation valve -N18-1)

Malfunction


Control difference

16791 Potentiometer for exhaust gas recirculation -G212-1)

Signal too low


Signal too high

16804 Bank 1, catalytic converter system1)

Efficiency too low – Testing lambda probe and lambda control upstream of catalytic converter ⇒ Chapter 24-4


– Testing intake system for tightness ⇒ Chapter 24-3

– Inspect exhaust system for leaks ⇒ 1.4/55; 1.4/74 Engine - Mechanics; Rep. Gr. 26

– Check catalytic converter ⇒ 1.4/55; 1.4/74 Engine - Mechanics; Rep. Gr. 26

16825 Tank ventilation system1)

Flow rate incorrect – Testing solenoid valve 1 for activated charcoal filter ⇒ Chapter 01-1, final control diagnosis

– Inspect hoses and connection pipes from fuel tank up to injection rail ⇒ 1.4/55; 1.4/74 Engine - Me-chanics; Rep. Gr. 20





01-3 page 6

01

16827 Tank ventilation valve -N80-1)


– Testing solenoid valve 1 for activated charcoal filter ⇒ Chapter 01-1, final control diagnosis

16828 Tank ventilation valve -N80-

Open circuit

16829 Tank ventilation valve -N80-

Short circuit

16845 Fuel level signal

Implausible signal – Testing signal of fuel gauge sender ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Loca-tions

16885 Vehicle speed signal1)

Implausible signal – Test speed signal ⇒ Chapter 24-6

– Read measured value block, display group 005, dis-play field 3 ⇒ Chapter 01-5

– Remove open circuit in wiring or short circuit accord-ing to current flow diagram ⇒ Current Flow Dia-grams, Electrical Fault Finding and Fitting Locations

16897 Engine control unit

Blocked – Adapt engine control unit to control unit for electronic immobiliser ⇒ Electrical System; Rep. Gr. 96.

16916 Pressure sensor for air condi-tioning system

Signal too low – Test G65 ⇒ Air conditioning system; Rep. Gr. 87

16917 Pressure sensor for air condi-tioning system

Signal too high

16946 Voltage supply

Voltage too low – testing voltage supply ⇒ Chapter 24-5

16947 Voltage supply

Voltage too high – testing voltage supply ⇒ Chapter 24-5

16955 Brake light switch -F-

Implausible signal – Test brake light switch and brake pedal switch ⇒ Chapter 24-6

16988 Control unit defective1)

– Replace engine control unit -J537- ⇒ Chapter 24-5



16991 Throttle valve control unit -J338-2)

Undervoltage on basic settings

– Adapt engine control unit to throttle valve control unit ⇒ Chapter 24-5

17022 Throttle valve control unit -J338-1)2)

Implausible signal – Check battery, if necessary charge ⇒ Electrical Sys-tem; Rep. Gr. 27

– Test throttle valve control unit ⇒ Chapter 24-2

17029 Air conditioning system inlet/outlet

– Testing signals from and to the air conditioning sys-tem ⇒ Electrical System; Rep. Gr. 90

17034 Exhaust gas warning light -K83-


– Testing signals from and to the warning light -K83- ⇒ Electrical System; Rep. Gr. 90

17040 Fuel consumption signal


– Check the fuel consumption signal ⇒ Electrical Sys-tem; Rep. Gr. 90.

– Test CAN databus ⇒ Chap. 24-6.




01-3 page 7

01

17510 Bank 1, probe 1 heating circuit1)

Short circuit to positive – Testing lambda probe heater upstream of catalytic converter ⇒ Chapter 24-4

– Remove short-circuit according to Current Flow Dia-gram ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Locations



Short circuit to positive – Test lambda probe heater downstream of catalytic converter ⇒ Chapter 24-4



Short circuit to earth – Testing lambda probe heater upstream of catalytic converter ⇒ Chapter 24-4



Open circuit – Testing lambda probe heater upstream of catalytic converter ⇒ Chapter 24-4

– Remove line interruption according to Current Flow Diagram ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Locations



Short circuit to earth – Test lambda probe heater downstream of catalytic converter ⇒ Chapter 24-4



Open circuit – Test injection valves ⇒ Chapter 24-3



17550 Load detection

Below limit – Adapt engine control unit to throttle valve control unit ⇒ Chapter 24-5


– Test accelerator pedal position sender ⇒ Chapter 24-2

– Test air filter ⇒ Chapter 24-1

– Check engine mechanics

17559 Bank 1, mixture adaptation range 11)

Below leanness limit – Test injection valves ⇒ Chapter 24-3

– Test fuel pump ⇒ 1.4/55; 1.4/74 Engine - Mechan-ics; Rep. Gr. 20



– Check exhaust gas recycling system ⇒ 1.4/55; 1.4/74 Engine - Mechanics; Rep. Gr. 26

– Inspect activated charcoal container system for leaks ⇒ 1.4/55; 1.4/74 Engine - Mechanics; Rep. Gr. 20




Below leanness limit




01-3 page 8

01

17563 Intake manifold pressure sender -G71-1)2)

Short circuit to positive – Testing intake manifold pressure sender ⇒ Chap. 24-2

– Testing intake system for tightness (unmetered air) ⇒ Chapter 24-3.17564

Intake manifold pressure sender -G71-1)2)

Open circuit/Short-cir-cuit to earth

17566 Intake manifold pressure sender -G71-1)2)

Implausible signal

1) If this fault occurs the engine control unit switches on the exhaust gas warning lamp in the dash panel insert. Meaning of the exhaust gas warn-ing lamp ⇒ Chapter 01-1

2) If this fault occurs the engine control unit switches on the EPC warning lamp in the dash panel insert. Meaning of the EPC warning lamp ⇒ Chapter 01-1



Self-diagnosis IVEdition 06.04S00.5309.04.20

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01-4 Self-diagnosis IV

Fault table, fault codes 17573...18100



Above richness limit – Test injection valves ⇒ Chapter 24-3

– Test fuel pump ⇒ 1.4/55; 1.4/74 Engine - Mechanics; Rep. Gr. 20



– Check exhaust gas recirculation system ⇒ 1.4/55; 1.4/74 Engine - Mechanics; Rep. Gr. 26





Above richness limit


Implausible signal – Test throttle valve control unit -J338- ⇒ Chapter 24-2.



Signal too low – Test throttle valve control unit ⇒ Chapter 24-2

– Adapt throttle valve control unit ⇒ Chapter 24-5.


Signal too high


Deviation of the injec-tion periods


– Test fuel pump ⇒ 1.4/55; 1.4/74 Engine - Mechanics; Rep. Gr. 20







17584 Bank1, lambda correction ac-cording to catalytic converter1)

Regulating limit reached





Self-diagnosis IV Edition 06.04S00.5309.04.20

01-4 page 2

01

17586 Linear lambda probe/pump current1)

Open circuit – Testing lambda probe and lambda control upstream of catalytic converter ⇒ Chapter 24-4

– Testing lambda probe heater upstream of catalytic converter ⇒ Chapter 24-417587

Linear lambda probe/pump current1)


17588 Linear lambda probe/pump current1)


17589 Linear lambda probe/refer-ence voltage1)

Open circuit – Testing lambda probe and lambda control upstream of catalytic converter ⇒ Chapter 24-4



– Test combustion misfiring ⇒ Chapter 28-1


Short circuit to earth




implausible

17604 Bank 1, probe 1, heating circuit1)

Electrical fault – Testing lambda probe heater upstream of catalytic converter ⇒ Chapter 24-4

17606 Bank 1, probe 2, heating circuit1)

Electrical fault – Test lambda probe heater downstream of catalytic converter ⇒ Chapter 24-4


Short circuit to positive – Test injection valves ⇒ Chapter 24-3








Open circuit – Test injection valves ⇒ Chapter 24-3


Open circuit


Open circuit


Open circuit


Short circuit to earth – Test dash panel insert ⇒ Electrical System; Rep. Gr. 90



17743 Engine torque monitoring 21)2)

Regulating limit ex-ceeded

– Testing intake system for tightness ⇒ Chap. 24-3.

– Inspect accelerator pedal position sender -G79- and -G185- ⇒ Chap. 24-2.

– Test throttle valve control unit -J338- ⇒ Chapter 24-2.




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01

17745 Bank 1, camshaft pos. sensor -G40-

Short circuit to earth – Inspecting hall sender ⇒ Chapter 28-1

17746 Bank 1, camshaft pos. sensor -G40-

Short circuit to positive – Check camshaft position sensor -G40- ⇒ Chap. 28-1

– Remove open circuit in wiring or short circuit accord-ing to current flow diagram ⇒ Current Flow Dia-grams, Electrical Fault Finding and Fitting Locations.

17749 Ignition outlet 11)

Short circuit to earth – Inspect ignition transformer ⇒ Chapter 28-1

– Remove open circuit in wiring or short circuit accord-ing to current flow diagram ⇒ Current Flow Dia-grams, Electrical Fault Finding and Fitting Locations.








Open circuit


Open circuit

17763 Ignition control cyl. 1

Open circuit3) – Inspect ignition transformer ⇒ Chapter 28-1

– Remove line interruption according to Current Flow Diagram ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Locations.


Short circuit to positive3) – Check the ignition coils with power output stage ⇒ Chapter 28-1.

– Remove short-circuit according to Current Flow Dia-gram ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Locations.


Short circuit to earth3)


Open circuit3)


Short circuit to positive3)




Open circuit3)






Open circuit3)







17796 Control unit defective1)2)




01-4 page 4

01

17806 Engine speed signal, TD

Short circuit to earth – Test engine speed sender ⇒ Chapter 24-3


17807 Engine speed signal, TD



Short circuit to earth – Test exhaust gas recirculation valve ⇒ Chapter 01-1, final control diagnosis.

– Check the EGR valve ⇒ 1.4/55; 1.4/74 Engine - Me-chanics; Rep. Gr. 26.17810

Exhaust gas recirculation valve -N18-1)



Control difference

17812 Exhaust gas recirculation sys-tem

Basic setting not per-formed

– Conduct basic setting (measured value block 074) ⇒ Chapter 01-7


Short circuit to positive – Test solenoid valve for activated charcoal filter ⇒ Chapter 01-1, final control diagnosis





Open circuit


Incorrect basic setting – Conduct basic setting (measured value block 074) ⇒ Chapter 01-7


Open circuit – Check the EGR valve ⇒ 1.4/55; 1.4/74 Engine - Me-chanics; Rep. Gr. 26.

– Test exhaust gas recirculation valve ⇒ Chapter 01-1, final control diagnosis.17850

Potentiometer for exhaust gas recirculation -G212-1)

Signal too high


Signal too low

17909 Fuel pump relay -J17-

Short circuit to earth – Test fuel pump relay -J17- ⇒ Chapter 01-1, final con-trol diagnosis

– Test fuel pump relay ⇒ Current Flow Diagrams, Elec-trical Fault Finding and Fitting Locations.



17912 Air intake system2)

Leak detected – Inspect intake air system for leaks (unmetered air) ⇒ Chapter 24-3





Open circuit – Test fuel pump relay ⇒ Current Flow Diagrams, Elec-trical Fault Finding and Fitting Locations

17950 Angle sender for TV drive -G187-2)

Implausible signal – Test throttle valve control unit ⇒ Chapter 24-2





01-4 page 5

01

17951 Angle sender for TV drive -G187-1)2)

Signal too low – Test throttle valve control unit ⇒ Chapter 24-2

17952 Angle sender for TV drive -G187-1)2)

Signal too high

17953 Throttle valve control 1)2)

Malfunction

17961 Level sender/intake manifold pressure signal2)

implausible ratio – Testing intake manifold pressure sender ⇒ Chap. 24-2

– Testing intake system for tightness (unmetered air) ⇒ Chapter 24-3.





Requirements for basic setting not fulfilled


17967 Throttle valve control unit -J338-1)2)

Incorrect basic setting

17968 Maximum engine speed ex-ceeded

– Repair mechanical damage


Undervoltage on basic settings

– Test battery, charge if necessary ⇒ Electrical Sys-tem; Rep. Gr. 27


17973 Throttle valve control unit

Bottom limit not reached

– Check throttle valve for damage or dirt


17977 CCS switch -E45-

Implausible signal – Inspecting cruise control system ⇒ Chap. 24-6

17978 Engine control unit blocked1)2)


– Adapt engine control unit to electronic immobiliser ⇒ Electrical System; Rep. Gr. 96.

– Test electronic immobiliser ⇒ Electrical System; Rep. Gr. 96

17989 Throttle valve control unit -J338-

Basic setting not per-formed


18010 Voltage supply tml. 30

Voltage too low – Perform procedure for voltage interruption ⇒ Chap. 24-5

18019 Fault lamp requirement on

Short circuit to earth – Inspect databus ⇒ Chapter 24-6

– Test exhaust gas warning lamp ⇒ Current Flow Dia-grams, Electrical Fault Finding and Fitting Locations

18020 Engine control unit

Incorrectly coded – Code engine control unit ⇒ Chapter 24-5




01-4 page 6

01

18021 Fault lamp requirement on

Open circuit/Short cir-cuit to positive

– Inspect databus ⇒ Chapter 24-6

– Test exhaust gas warning lamp ⇒ Current Flow Dia-grams, Electrical Fault Finding and Fitting Locations

18034 Data BUS drive

Missing message from gearbox CU



Signal too low – Test accelerator pedal position sender ⇒ Chapter 24-2


Signal too high

18041 Sender 2 for accelerator pedal position -G185-1)2)

Signal too low

18042 Sender 2 for accelerator pedal position -G185-1)2)

Signal too high


Missing message from air conditioning system CU


– Testing air conditioning system CU ⇒ Heating and Air conditioning; Rep. Gr. 87


Missing message from airbag CU


– Test airbag control unit ⇒ Body Fitting Work; Rep. Gr. 01


missing message form electron. CU


– Read out fault memory of electrical system control unit ⇒ Electrical System; Rep. Gr. 90

18047 Sender 1/2 for accelerator pedal position -G79- + -G185-2)

Implausible signal – Test accelerator pedal position sender ⇒ Chapter 24-2


– Inspect engine control unit power supply ⇒ Chapter 24-5

– Replace engine control unit -J537- ⇒ Chapter 24-5

18049 Read out fault memory of air conditioning CU

– Read out air conditioning system control unit fault memory ⇒ Heating, Air conditioning; Rep. Gr. 01


defective – Inspect databus ⇒ Chapter 24-6

– Read out fault memories of all control units (automat-ic test sequence) ⇒ Chapter 01-1


Missing message from ABS CU


– Read out fault memories of all control units (automat-ic test sequence) ⇒ Chapter 01-1


Missing message from combiinstrument


– Test dash panel insert ⇒ Electrical System; Rep. Gr. 90

18060 Read out fault memory of gearbox CU

– Self-diagnosis of automatic gearbox CU ⇒ Automatic Gearbox; Rep. Gr. 01




01-4 page 7

01

18061 Read out fault memory of ABS CU

– Self-diagnosis of ABS control unit ⇒ Running Gear; Rep. Gr. 45

18062 Read out fault memory of the combi-instrument

– Self-diagnosis of the dash panel insert control unit ⇒ Electrical System; Rep. Gr. 90

18064 Air conditioning system inlet/outlet

Short circuit to earth – Testing air conditioning system ⇒ Heating, Air con-ditioning; Rep. Gr. 87

– Inspect databus ⇒ Chapter 24-618065 Air conditioning system inlet/outlet


18081 Vehicle speed signal

Error message from ABS CU

– Self-diagnosis of ABS control unit ⇒ Chassis; Rep. Gr. 45

18085 Fault lamp for electr. accelera-tor control -K132-1)

Short circuit to positive – Inspect databus ⇒ Chapter 24-6

– Test dash panel insert ⇒ Electrical System; Rep. Gr. 90




Open circuit

18097 Databus drive

Implausible message from electron. CU

– Test CAN databus cables ⇒ Chap. 24-6

– Inspecting vehicle voltage control unit -J519- ⇒ Electrical System; Rep. Gr. 90.


Open circuit – Inspect databus ⇒ Chapter 24-6





1) If this fault occurs the engine control unit switches on the exhaust gas warning lamp in the dash panel insert. Meaning of the exhaust gas warn-ing lamp ⇒ Chapter 01-1.

2) If this fault occurs the engine control unit switches on the EPC warning lamp in the dash panel insert. Meaning of the EPC warning lamp ⇒ Chapter 01-1.

3) The faults related to the "ignition control..." regarding the cables between the engine control unit and the power output stage in the ignition coil, with which the power output stages are actuated by the engine control unit.




01-4 page 8

01


Self-diagnosis VEdition 06.04S00.5309.04.20

01-5 page 1

01

01-5 Self-diagnosis V

Measured value blocks

Safety measures

If test and measuring devices are required during test drives observe the following:

♦ Always secure the test and measuring devices on the rear seat and have a second person operate them there.

If the test and measuring devices are operated from the passenger seat the passenger could be injured by the re-lease of the passenger airbag in the event of an accident.

Reading measured value block



Test conditions

• The coolant temperature must be at least 80°C ⇒ dis-play group 004, display field 3.

• All electrical consumers, e.g. lights and rear window heater, must be switched off (radiator fan must not run).

• If vehicle is equipped with air conditioning, this must be switched off.


• No fault must be present in the fault memory ⇒ Chap. 01-1, interrogate fault memory and erase.

Procedure


– Select function 08 „Read measured value block“ and the desired display group number.

Display group number 004 is an example to represent the sequence.

Proceed according to the following table to switch to an-other display group:

Read measured value block HELPEnter display group number XXX

NoteRead measured value block 4 850 rpm 13.9V 88 C 41 C

Note


Self-diagnosis V Edition 06.04S00.5309.04.20

01-5 page 2

01

– If the specifications are achieved in all the display

fields, press key .


Measured value blocks, display groups 001...006 - Basic functions

Display group 001 - Basic functions:

• Engine idling

Meaning of 8-digit numerical block

Display group

-V.A.G 1551- -V.A.G 1552-

higher Press key Press key

lower Press key Press key

skip Press key Press key

3

1

C C

Read measured value block 1 → ⇐ Read out on display:

xxxx rpm xx.x °C xx.x % xxxxxxxx

1 2 3 4 ⇐ Display field Specification Analysis:

Setting require-ments

10111111 ⇒ 01-5 page 2

Lambda control value -15...15 % ⇒ 01-5 page 8

Coolant temperature 80...110 °C ⇒ 01-5 page 3

Engine speed (idling speed) ⇒ 01-5 page 3

Vehicles with engine code AUA 650...850 rpm1)

1) Current value ⇒ Inspection and Maintenance

Vehicles with the engine codes BBY, BKY 660...860 rpm1)

Vehicles with automatic gearbox (engine codes AUA, BBY, BKY)

580...780 rpm1)

Vehicles with engine code AUB 740...940 rpm1)

Vehicles with engine code BBZ 580...780 rpm1)

Meaning if display = 1

1 2 3 4 5 6 7 8 Meaning

1 Coolant temperature more than 80°C1 Engine speed less than 2000 rpm

1 Throttle valve closed

1 Lambda control o.k.

1 Operating state - idling



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Analysis of display group 001, engine speed (idling speed)

Analysis of display group 001, coolant temperature


• Engine idling

1 AC compressor disconnected

1 Catalyst hot (over 300 °C)

1 No fault detected in self-diagnosis

Dis-play field

Readout on dis-play:

Possible cause of fault Rectifying fault

1 less than nominal value

♦ Throttle valve control unit jams/defective – Test throttle valve control unit ⇒ Chapter 24-2

♦ Air filter element very dirty – Replace air filter element ⇒ Chap. 24-1

greater than nominal value

♦ Throttle valve control unit jams/defective – Interrogate fault memory ⇒ Chapter 01-1

♦ Large unmetered air volume (cannot be compensated by idle stabilizer)



– Performing idling test ⇒ Chap. 24-3

Dis-play field



2 less than 80 °C

♦ Engine too cold – Conduct test drive if necessary

♦ Sender for coolant temperature or wiring to engine control unit

– Test coolant temperature sender ⇒ Chapter 24-2

♦ Coolant regulator defective – Test coolant thermostat ⇒ 1.4/55, 1.4/74 Engine - Mechanical Components; Rep. Gr. 19

greater than 110 °C

♦ Radiator dirty – Clean radiator

♦ Radiator fan not operational – Inspect proper operation ⇒ Current Flow Diagrams, Electrical Fault Finding and Fit-ting Locations

♦ Coolant regulator defective – Test coolant thermostat ⇒ 1.4/55, 1.4/74 Engine - Mechanical Components; Rep. Gr. 19



Meaning if display = 1

1 2 3 4 5 6 7 8 Meaning



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Analysis of display group 002, injection period

Analysis of display group 002 intake manifold pressure


• Engine idling


xxxx rpm xx % x.x ms xxx mbar


Intake manifold pressure

240...420 mbar ⇒ 01-5 page 4

Injection period 2.0...4.0 ms ⇒ 01-5 page 4

Engine load 10...20 % ⇒ 01-5 page 8

Engine speed (idling speed) xxxx rpm1)

1) Display group 001, display field 1 ⇒ 01-5 page 2.

⇒ 01-5 page 3

Dis-play field



3 less than 2.0 ms

♦ High fuel volume from the activated char-coal filter system

– Testing solenoid valve 1 for activated charcoal filter ⇒ Chapter 01-1, final con-trol diagnosis

♦ Incorrect injection valve with too great flow rate fitted


– Check part No. of the injection valves ⇒ Spare parts catalogue

greater than 4.0 ms

♦ Increased engine load due to electric con-sumers, air conditioning system, engaged driving position or power steering to the stop

– Eliminate load (air conditioning, power steering etc.)

♦ Incorrect injection valves with too small flow rate fitted


– Check part No. of the injection valves ⇒ Spare parts catalogue

Dis-play field



4 less than 240 mbar

♦ Large volume of unmetered air between in-take manifold and air filter

– Eliminate unmetered air

greater than 420 mbar

♦ Driving position engaged (automatic gear-box)

– Put selector lever in P or N

♦ Engine loaded by auxiliary equipment – Eliminate load (air conditioning, power steering etc.)




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• Engine idling

♦ Re display field 3:

♦ As soon as a fault concerning the coolant temperature sender -G62- is stored in the fault memory, the engine control unit uses the intake manifold temperature as a replacement value to start the engine (starting tem-perature - replacement value) The temperature then rises according to a model sequence stored in the control unit. If the engine is warm after a certain period a fixed replacement value is displayed. This fixed sub-stitute value depends on the intake air temperature.


♦ The overall temperature range is indicated as nominal value. The nominal value must be higher than the am-bient temperature.


xxxx rpm xxx mbar xx ° xx °1 2 3 4 ⇐ Display field Specification Analysis:

Ignition angle 0...10 ° BTDC —

Throttle valve angle (potenti-ometer 1 -G187-)

0...11 ° ⇒ 01-5 page 8

Intake manifold pressure 240...420 mbar ⇒ 01-5 page 4



⇒ 01-5 page 3


xxxx rpm xx.x V xxx °C xxx °C1 2 3 4 ⇐ Display field Specification Analysis:

Intake manifold temperature

-40...120 °C ⇒ 01-5 page 6


Supply voltage of the engine control unit 12.5...14.5 V ⇒ 01-5 page 6



⇒ 01-5 page 3

Note



01-5 page 6

01

Analysis of display group 004, engine control unit voltage supply

Analysis of display group 004, coolant temperature

Dis-play field



2 less than 12.5 V

♦ Generator defective, battery heavily dis-charged

– Inspect generator and battery voltage, charge battery ⇒ Electrical System; Rep. Gr. 27

♦ Battery heavily loaded just after start by a high charge current or by auxiliary equip-ment

– Increase engine speed slightly for a few minutes and switch off additional con-sumers

♦ Transition resistance in the power supply or earth connection for engine control unit

– Inspect engine control unit power supply ⇒ Chapter 24-5

♦ Current consumption with ignition off – Eliminate current consumption

greater than 14.5 V

♦ Voltage regulator on generator defective – Check voltage regulator, if necessary re-place ⇒ Electrical System; Rep. Gr. 27

♦ Overvoltage due to starting aid or quick charger

– Interrogate fault memory ⇒ Chapter 01-1

Dis-play field

Read-out on display:


3 less than 80 °C

♦ Engine too cold – Conduct test drive if necessary

♦ Coolant temperature sender or cable con-nection to engine control unit faulty


♦ Coolant regulator defective – Test coolant thermostat ⇒ 1.4/55; 1.4/74 Engine - Mechanical Components; Rep. Gr. 19

greater than 110 °C

♦ Radiator dirty – Clean radiator

♦ Radiator fan not operational – Inspect proper operation ⇒ Current Flow Diagrams, Electrical Fault Finding and Fit-ting Locations

♦ Coolant regulator defective – Test coolant thermostat ⇒ 1.4/55; 1.4/74 Engine - Mechanical Components; Rep. Gr. 19



constant - 40 °C

♦ Open circuit or short circuit to positive – Test coolant temperature sender ⇒ Chapter 24-2

constant 120 °C

♦ Short circuit to earth



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01

Analysis of display group 004, intake manifold temperature


• Engine idling


• Engine idling


♦ The overall temperature range is indicated as nominal value. The display value must be higher than the am-bient temperature.

Dis-play field

Read-out on display:


4 constant - 40 °C

♦ Open circuit or short circuit to positive – Inspecting intake manifold temperature sender ⇒ Chap. 24-2

constant 120 °C

♦ Short circuit to earth


xxxx rpm xx % xxx km/h Text


Operating condi-tion (idling, partial load, enrichment, trailing throttle)

Idling

—

Driving speed 0 km/h —




⇒ 01-5 page 3


xxxx rpm xx % xxx °C xx.x %


Level correction factor

-30,0...5,0 % —

Intake manifold temperature -40...120 °C ⇒ 01-5 page 7




⇒ 01-5 page 3

Note



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Measured value blocks, display groups 010...029 - Ignition

Display group 010 ignition:

• Engine idling

Analysis of display group 010, engine load

Analysis of display group 010, throttle valve angle

Read measured value block 10 → ⇐Read out on display:

xxxx rpm xx % xx % xx.x °1 2 3 4 ⇐ Display field Specification Analysis:

Ignition angle 0...10.0 ° BTDC —


0...11 % ⇒ 01-5 page 8




⇒ 01-5 page 3

Dis-play field



2 less than 10 %

♦ Lower value can only occur during trailing throttle driving

greater than 20 %

♦ Poor idling (engine not running on all cylin-ders)



♦ Electrical consumers on – Disconnect electric consumer

♦ Steering wheel at limit stop – Put steering wheel in centre position

♦ Driving position engaged (automatic gear-box)

– Put selector lever in P or N

Dis-play field



3 greater than 11 %

♦ Engine control unit not adapted to throttle valve control unit


♦ Throttle valve potentiometer in throttle valve control unit defective


♦ Throttle valve blocked – Eliminate cause




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01

Display group 014 - Ignition, sum of misfiring de-tection:

• Driving

Analysis of display group 014, sum of ignition misfiring

Display group 015 - ignition, cylinder misfiring 1 to 3:

• Driving


xxxx rpm xxx % xxx Text


Combustion mis-firing detection (activated, deacti-vated)

activated

—

Sum of ignition misfiring 0 ⇒ 01-5 page 9

Engine load 12…100 % —

Engine speed

Vehicles with engine code AUA 650…5700 rpm —

Vehicles with the engine codes BBY, BKY 660…5700 rpm —


580…5700 rpm—

Vehicles with engine code AUB 740…6600 rpm —

Vehicles with engine code BBZ 580…6600 rpm —

Dis-play field



3 greater than 0

♦ Spark plug defective

♦ Spark plug connector defective

♦ Ignition transformer defective

– Test spark plugs and spark cables with spark plug connector ⇒ Chap. 28-1

– Inspect ignition transformer ⇒ Chapter 28-1

♦ Injection valve defective – Test injection valves ⇒ Chapter 24-3

♦ Exhaust gas recirculation valve jams/soiled – Test exhaust gas recirculation valve ⇒ Chapter 01-1, final control diagnosis.



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01

Display group 016 - ignition, cylinder misfiring 4:

• Driving

Analysis of display groups 015 and 016, ignition misfiring cyl. 1 to cyl. 4

Display group 022 ignition, knock control:

• Driving


xxx xxx xxx Text


Combustion mis-firing detection (activated, deacti-vated)

activated

—

Ignition misfiring cylinder 3 0 ⇒ 01-5 page 10




xxx — — Text


Combustion misfir-ing detection (activated, deacti-vated)

activated

—

— —

— —


Dis-play

fields



Dis-play

group 15

display field 1 to 3

greater than 0

♦ Spark plug defective

♦ Spark plug connector defective

♦ Ignition transformer defective

– Test spark plugs and spark cables with spark plug connector ⇒ Chap. 28-1

– Inspect ignition transformer ⇒ Chapter 28-1

and display group 16 display field 1

♦ Injection valve defective – Test injection valves ⇒ Chapter 24-3

♦ Exhaust gas recirculation valve jams/dirty – Test exhaust gas recirculation valve ⇒ Chapter 01-1, final control diagno-sis.



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♦ Notes on display groups 3 and 4:

♦ When idling the display value must be 0.0 .♦ 14 is the largest ignition angle relief.

Display group 023 - ignition, knock control:

• Driving


xxxx rpm xxx % xx.x ° xx.x °1 2 3 4 ⇐ Display field Specification Analysis:

Ignition angle relief cylinder 2 through knock control

0...14 ° ⇒ 01-5 page 12


0...14 ° ⇒ 01-5 page 12

Engine load 15...100 % —

Engine speed




580…5700 rpm—



Note


xxxx rpm xxx % xx.x ° xx.x °1 2 3 4 ⇐ Display field Specification Analysis:

Ignition angle re-lief cylinder 4 through knock control

0...14 ° ⇒ 01-5 page 12


0...14 ° ⇒ 01-5 page 12


Engine speed


Vehicles with the engine codes BBY, BKY

660…5700 rpm—


580…5700 rpm—





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01

♦ Notes on display groups 3 and 4:

♦ When idling the display value must be 0.0 .♦ 14 is the largest ignition angle relief.

Analysis of display groups 022/023, ignition angle relief

Display group 028 - ignition, knock control:

• Driving

• Diagnostic device in function 04 - basic setting

Note

Dis-play field



3 and 4

All 14 ° cylinder

♦ Knock sensor defective – Inspecting knock sensor ⇒ Chapter 28-1

♦ Plug connection corroded – Check knock sensor plug connection ⇒ Chap. 28-1

♦ Knock sensor incorrectly tightened – Release knock sensor and tighten (20 Nm)

♦ Component parts on engine loose – Attach component parts

♦ Poor fuel quality – Change fuel type

Once cyl-inder clearly deviates from the others

♦ Plug connection corroded – Check knock sensor plug connection ⇒ Chap. 28-1

♦ Engine damage – Test compression ⇒ 1.4/55; 1.4/74 Engine - Mechanical Components; Rep. Gr. 15.

♦ Component parts on engine loose – Attach component parts

System in basic setting 28 → ⇐ Read out on display:

xxxx rpm xx % xxx.x °C Text


Result knock sen-sor test (Test ON/Test OFF/Syst. o.k./Syst. n.o.k.)

Syst. o.k. —



Engine speed 2000...4000 rpm —


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01-6 page 1

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01-6 Self-diagnosis VI


Measured value blocks, display groups 030...049, 099 - Lambda control

Display group 030 - lambda control:

• Engine idling


♦ The 3rd display position is only set to 1 in the partial load region.

Meaning of the 3-digit numerical block display field 1:

Display group 031 - lambda control, lambda val-ues upstream of catalytic converter:

• Engine idling

• Coolant temperature ≥ 80 °C


xxx xxx — —


— —

— —

Status lambda control downstream of cat-alytic converter

110 ⇒ 01-6 page 1

Status lambda control upstream of catalytic convert-er

111 ⇒ 01-6 page 1

Note

Meaning if display positions = 1

1 2 3

1 Lambda control active

1 Lambda probes operational

1 Lambda probe heating on


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01-6 page 2

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Display group 032 - Lambda control, Lambda in-itialisation values:

• Engine idling

♦ Re display fields 1 and 2:

♦ Low readouts indicate that the engine is running too rich and the lambda control therefore produces a lean-er mixture.

♦ High readouts mean that the engine is running too lean and the lambda control therefore produces a rich-er mixture.

♦ If the control unit is dead all initialisation values are re-set.

♦ add = additive - The effect of the fault (e.g. unmetered air) becomes increasingly less as engine speed rises. In the case of an additive initialisation value the injec-tion period is changed by a fixed rate. This rate is in-dependent of the basic injection period.

♦ mul = multiplicative - The effect of the fault (e.g. faulty injector) becomes greater as engine speed rises. The multiplicative learned value is a percentage change in the injection period. This change is dependent on the basic injection period.

♦ Initialisation conditions for partial load. Coolant tem-perature at least 75 C, intake air temperature max. 90 C, driving mode.

Read measured value block 31 → < Readout on display

x.xxxx x.xxxx

1 2 3 4 < Display field Specification Analysis:

No display --- ---

No display --- ---

Lambda nominal value - Bank 1 0,9900…1,0100 ---

Lambda actual value - Bank 1 0,9600…1,0400 ---


xx.x % xx.x % — —


— —

— —

Lambda learned value under partial load (multiplicative) upstream of catalytic con-verter

-10,0...10,0 % ⇒ 01-6 page 3

Lambda learned value in idling (additive) upstream of catalytic converter

-10,0...10,0 % ⇒ 01-6 page 3

Note



01-6 page 3

01

Analysis of display group 032, Lambda control, Lambda learned values

Display group 033 - Lambda control, Lambda control values:

• Engine idling

Dis-play field



1 and 2

low lamb-da learned values

♦ Low learned values in idling at normal learned values in partial load: Oil dilution (higher fuel content in the oil) possible

– Disappears after motorway driving or oil change

♦ Injection valve leaks – Test injection valves ⇒ Chapter 24-3

♦ Fuel pressure too high – Test fuel pressure regulator and holding pressure ⇒ Engine 1.4/55; 1.4/74 Me-chanics; Rep. Gr. 20.

♦ Solenoid valve 1 for activated charcoal filter -N80- constantly open

– Testing solenoid valve 1 for activated charcoal filter ⇒ Chapter 01-1, final con-trol diagnosis

♦ Lambda probe heating defective or lambda probe dirty


Dis-play field



1 and 2

high lambda initialisa-tion val-ues

♦ High learned values in idling at less high learned values in partial load: Unmetered air in intake manifold region possible


♦ Unmetered air between air filter and throttle valve

– Eliminate cause

♦ Unmetered air at the exhaust manifold gas-ket

– Eliminate cause

♦ Injection valve blocked – Test injection valves ⇒ Chapter 24-3

♦ Fuel pressure too low – Test fuel pressure regulator and holding pressure ⇒ 1.4/55; 1.4/74 Engine - Me-chanics; Rep. Gr. 20.

♦ Lambda probe heating defective or lambda probe dirty



xx.x % x.xxx V — —


— —

— —

Lambda probe voltage before catalyst 0.4...0.5 V —

Lambda control before catalyst -15,0...15,0 % ⇒ 01-6 page 4



01-6 page 4

01


♦ The display must oscillate around 0. If 0 is constantly displayed, the lambda control has switched from closed-loop to open-loop control because of a fault in the lambda control. Interrogate fault memory ⇒ Chapter 01-1.


♦ Display 0.450 V equals approx. = 1.0.

♦ Voltage signal „Mixture rich“ (low level of residual ox-ygen) is below 0.45...V.

♦ Voltage signal „Mixture lean“ (a lot of residual oxygen) is above 0.45...V.

♦ Through its structure the wide-band lambda probe en-ables a permanent lambda control due to the signal routing for deviations as of = 1.

♦ The control is performed dynamic, as the deviation from the specification is current and is known as the concrete value.

Analysis of display group 033, lambda control upstream of catalytic converter

Display group 034 - Lambda control, diagnosis of lambda probe upstream of catalytic converter (ageing test over amplitude quality grade)

– Blip two short accelerations above 5000 rpm

• Vehicle standing, engine running at high speed


Note

Note

Dis-play field



1 not within tolerance

♦ Minimum range: Engine too rich, lambda control leans off

♦ Plus range: Engine too lean, lambda control enriches

– wait 30 seconds until the display has stabilised

♦ Unmetered air – Testing intake system for tightness ⇒ Chapter 24-3

♦ Injection valve defective – Test injection valve ⇒ Chap. 24-3

♦ Lambda learned values on limit – Test lambda initialisation values in dis-play group 032 ⇒ 01-6 page 3



01-6 page 5

01

♦ regarding display fields 3 and 4:

♦ The period duration indicates the time between two voltage jumps (e.g. rich - lean - rich) of the lambda probe and is thus an indication of the age condition of the lambda probe. If the given time is exceeded, dis-play field 4 = B1 S1 N.O.K.

Display group 036 - lambda control, operation after catalyst

• Vehicle standing, brake pedal activated, engine run-ning at raised idling (1500….4000 rpm)



xxxx rpm xxx.x °C x.x s Text


Result of test of lambda probe age-ing upstream of catalytic converter (Test OFF/Test ON/B1 S1 o.k./B1 S1 n.o.k.)

B1 S1 o.k. —

Period of lambda probe up-stream of catalytic converter

max. 1.0 s —

Catalytic converter temperature — —

Engine speed 1500…3900 rpm —

Note


x.xxx V Text — —


— —

— —

Test lambda probe downstream of catalyt-ic converter (Test OFF/Test ON/B1 S2 n.o.k.)

B1 S2 o.k.—

Lambda probe voltage after catalytic converter 0.000...1.000 V ⇒ 01-6 page 6



01-6 page 6

01

Analysis of display group 036, lambda probe voltage, lambda probe downstream of catalytic con-verter

Display group 037 - Lambda control, Lambda probes downstream of catalytic converter:

• Driving



♦ Voltage signal „Mixture rich (low level of residual oxy-gen)“ is at approx. 0.7...1.0 V.

♦ Voltage signal „Mixture lean (high level of residual ox-ygen)“ is at approx. 0.0...0.3 V.

♦ A voltage jump from 0.7...1.0 V to 0.0...0.3 V or vice versa takes place at the transition from „rich“ to „lean“ and vice versa ( = 1.0).

Dis-play field



1 constant 1.100 V

♦ Short-circuit to positive terminal in: Lambda probe, lambda probe cable, earth lead, en-gine control unit

– Test basic voltage of the lambda probe downstream of catalytic converter ⇒ Chap. 24-4

– Test lambda probe after catalytic con-verter ⇒ Chapter 24-4

constant between 0.400 ...0.500 V

♦ Line interruption in: Lambda probe, lambda probe cable, earth lead, engine control unit

constant 0.000 V

♦ Short-circuit to earth in: Lambda probe, lambda probe cable, earth lead, engine con-trol unit


xx.x % x.xxx V x.x % Text


Test lambda probes (Test ON/Test OFF/Syst. o.k./Syst. n.o.k.)

Syst. o.k. —

Ignore — —

Lambda probe voltage after catalytic converter

0.000...1.000 V ⇒ 01-6 page 6

Engine load 12,0...40,0 % ⇒ Chapter 01-5

Note



01-6 page 7

01

♦ In view of the steep voltage jump the lambda control is not able to maintain constant the ideal mixture com-position which corresponds to = 1.0. The control constantly fluctuates back and forward between the „slightly too lean“ and „slightly too rich“ states.

♦ The readout must in some cases be less than 0.3 V and in some cases more than 0.6 V. The readout be-low 0.45 V indicates a lean mixture while above 0.45 V indicates a rich mixture.

♦ At idling speed, the voltage of the lambda probe up-stream of the catalytic converter -G39- must fluctuate between a rich and leaner mixture. The voltage of the lambda probe downstream of the catalytic converter -G130- should indicate a constant rich or lean mixture. If the voltage also fluctuates downstream of the cata-lytic converter, either the catalytic converter is faulty (Read measured value block 046 ⇒ 01-6 page 8) or the probes have been wrongly connected (irregular engine running). Lambda control varies between -15...15 %.

Voltage of the 4-pin lambda probe in U in mV

A: Lambda probe voltage high

rich mixture (fuel surplus or air shortage)

high CO value

B: Lambda probe voltage low

lean mixture (fuel shortage or air surplus)

low CO value

Display group 041 - lambda control, lambda probe heating:

• Engine idling


— Text xxx ohms Text


Lambda probe heating down-stream of catalytic converter

Ht. after c. ON Ht. after c. OFF

—

Resistance lambda probe heating downstream of cata-lytic converter

— —

Lambda probe heating upstream of cata-lytic converter

Ht. bf. c. ON Ht. bf. c. OFF

—

— —



01-6 page 8

01

Depending on the operating state of the engine the lamb-da probe heaters are switched on or off, i.e. the readouts in display field 2 and 4 may show either „Htg.u(d)C.ON“ or „Htg.u(d)C.OFF“.

Display group 46 - Lambda control, Diagnosis of catalyst (conversion test):


• Vehicle standing, engine running at high speed

• No fault in fault memory, coolant temperature 60...120 °C, lambda control active and stable

Display group 099 - Lambda control, Operating condition of lambda control:

• Engine idling

Note


xxxx rpm xxx.x °C xx.x % Text


Result of the cata-lyst conversion test (Test OFF/Test ON/Cat B1 O.K./Cat B1 N.O.K.)

Cat B1 o.k. —

Measured value catalytic con-version

at least 60 %—

Catalytic converter temperature at least 300 °C —



xxxx rpm xxx °C xx.x % Text


Operating condi-tion of lambda control

OFF ON —

Lambda control before cata-lyst

-15,0...15,0 % ⇒ 01-6 page 4

Coolant temperature 80...110 °C ⇒ Chapter 01-5


1) Display group 001, display field 1 ⇒ Chap. 01-5.

⇒ Chapter 01-5


Self-diagnosis VIIEdition 06.04S00.5309.04.20

01-7 page 1

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01-7 Self-diagnosis VII


Measured value blocks, display groups 050...069 - Speed control

Display group 050 - Speed control, Operating conditions:

• Engine idling


♦ The nominal engine speed specified by the engine control unit (calculated value internal to control unit) is displayed.

♦ The nominal engine speed is raised if the battery is greatly discharged or if the engine is extremely over-heated.

♦ regarding display fields 3 and 4:

♦ „OFF“ is always displayed on vehicles without air con-ditioning system.


xxxx rpm xxxx rpm Text Text


Operating state of AC compressor

ON OFF

—

Operating condition of air conditioning system

ON OFF —

Engine speed (idling speed - specified value)

Vehicles with engine code AUA

750 rpm (830 rpm)1)

1) Air conditioning switched on

Vehicles with engine code AUB

840 rpm (870 rpm)1)

Vehicles with the engine codes BBY and BKY

760 rpm

Vehicles with engine code BBZ

680 rpm

Vehicles with automatic gear-box

680 rpm (800 rpm)1)

Engine speed (idling speed - actual value) xxxx rpm2)

2) Display group 001, display field 1 ⇒ Chap. 01-5

⇒ Chapter 01-5

Note

Note


Self-diagnosis VII Edition 06.04S00.5309.04.20

01-7 page 2

01

Display group 054 - Lambda control:

• Driving


♦ The operating condition is displayed according to the speed or load. As of increased speed „trailing throttle“ with closed throttle valve is only displayed up to 1450 rpm, after that it returns to idling.

Display group 055 - Speed control, idle stabiliz-er:

• Engine idling


xxxx rpm Text xxx % xxx %


Throttle valve an-gle (potentiome-ter 1 -G187-)

3...97 %—

Sender 1 for accelerator pedal position -G79-

3...97 % —

Operating position: Idling, part load, en-richment, overrun, full load

— —

Engine speed

Vehicles with engine code AUA 650 ... 5700 rpm —

Vehicles with the engine codes BBY, BKY 660 ... 5700 rpm —


580 ... 5700 rpm —

Vehicles with engine code AUB 740 ... 6600 rpm —

Vehicles with engine code BBZ 580 ... 6600 rpm —

Note


xxxx rpm xx Nm xx.x % xxxxx


Operating condi-tions

xxxxx ⇒ 01-7 page 3

Initialisation value idling con-trol

Air conditioning on -6,0...8,0 % —

Air conditioning off -3,0...8,0 %

Idling control -10…0 Nm —



⇒ Chapter 01-5



01-7 page 3

01


♦ The display shows to what extent the idling stabilizer has „disinitialised“ from the constructively given mean value. On a new engine the value is in the positive re-gion because of the higher friction, on a run-in engine it is in the negative region.

Display field 4 - Operating conditions, meaning of the digits in the 5-digit number block

Display group 056 - engine speed control, idling speed stabilisation:

• Engine idling

Note

Meaning if display positions = 1

1 2 3 4 5 Meaning

1 Air conditioning compressor on

1 Driving position engaged

1 Air conditioning switched on

x No meaning

x No meaning


xxxx rpm xxxx rpm xx Nm xxxxx




Idling control -10...0 Nm —

Engine speed (idling speed - specified value)

Vehicles with engine code AUA

750 rpm (830 rpm)1)

1) Air conditioning switched on

Vehicles with engine code AUB

840 rpm (870 rpm)1)

Vehicles with the engine codes BBY and BKY

760 rpm

Vehicles with engine code BBZ

680 rpm

Vehicles with automatic gear-box:

680 rpm (800 rpm)1)

Engine speed (idling speed - actual value) xxxx rpm2)


⇒ Chapter 01-5



01-7 page 4

01


♦ The nominal engine speed specified by the engine control unit (calculated value internal to control unit) is displayed.

♦ The nominal engine speed is raised if the battery is greatly discharged or if the engine is extremely over-heated.

Display group 60 - Speed control, Electronic Throttle Adaptation:

• Ignition on, engine stopped

• Diagnostic device in function 04 „basic setting“

♦ To display group 60:

♦ The adaptation of the throttle valve control unit occurs with the ignition switched on and accelerator pedal not depressed.

♦ The engine control unit is adjusted to the throttle valve control unit by selecting display group under function 04 „Basic setting“. This adjustment must always be performed if a different throttle valve (or completely different engine) or a different engine control unit has been fitted.

♦ If the power supply was interrupted (battery discon-nected) an adaptation must also be carried out ⇒ Chap. 24-5. Work sequence after a power supply interruption.

♦ During adaptation the counter in display field 3 counts up to 12.

♦ The basic setting may only be ended once the counter in display field 3 has reached step 12.

Display group 61 - engine speed control, EPC:

• Driving

Note


xxx % xxx % xx Text


Adaption state (ADP runs, ADP o.k. or ADP n.o.k.)

ADP o.k. —

Initialisation step counter 0...12 —

Throttle valve angle (potentiometer 2 -G188-)

3...97%—

Throttle valve angle 3...97% —

Potentiometer 1 -G187-

Note



01-7 page 5

01

Display group 062 - engine speed control, EPC:


Measured value blocks, display groups 070...075 - exhaust gas recirculation

Display group 070 - Exhaust gas reduction, Acti-vated charcoal filter system diagnosis (tank ven-tilation system):

• Engine idling

• Coolant temperature minimum 80 °C



xxxx rpm — xxx.x % xxxxx





0...100 % —

— —

Engine speed




580…5700 rpm—




xx % xx % xx % xx %


Sender 2 for accel-erator pedal posi-tion -G185-

0...100 %—

Sender 1 for accelerator ped-al position -G79-

0...100 %—

Throttle valve angle (potentiometer 2 -G188-)

3...97 %—

Throttle valve angle (potentiometer 1 -G187-) 3...97 % —



01-7 page 6

01

TVV means Tank Vent Valve (activated charcoal filter so-lenoid valve 1).


♦ During diagnosis the display fluctuates in the region from 13...25 % to approx. 6 %.

Display group 074 - Exhaust gas reduction, Ex-haust gas recirculation valve adaptation:




♦ The adaptation of the exhaust gas recirculation valve occurs with the ignition on.

♦ The engine control unit is adapted to the exhaust gas recirculation valve by selecting display group 074 un-der function 04 „Basic position“. This adaption must


xx % xx % xxx mbar Text


Result of the acti-vated charcoal fil-ter system diagnosis (Test OFF/Test ON/TVV O.K./ TVV N.O.K.)

TVV o.k.

—

Intake manifold pressure 240…420 mbar —

Result of current diagnosis > 25 % —

Opening level 13…25 % —

Note

Note


x.x V x.x V x.xxx V Text


Adaption state (ADP runs, ADP o.k. or ADP n.o.k.)

ADP o.k.—

Current pot voltage value 0,300…4.600 V —

100 %- Position 2,9…4.6 V —

0 - Position (basic setting) 0,3…1.3 V —

Note



01-7 page 7

01

always be performed if another EGR valve (or com-pletely different engine) or another engine control unit has been installed.

Display group 075 - Exhaust gas recirculation:

• Engine idling


– Briefly blip throttle 5 times up to max. speed.


♦ An error can already occur under 140 mbar.

Measured value blocks, display group 100 - readiness code

Display group 100 - readiness code:

• Engine idling

Display field 1 - Readiness code - Meaning of the digits in the 8-digit numerical block


xxxx rpm xxx mbar xxx mbar Text


Result: Test ON/Test OFF, Syst. o.k./Syst. n.o.k.

Syst. o.k.—

Intake manifold pressure dif-ference

min. 50 mbar —

Intake manifold pressure 240…420 mbar —


Note


xxxxxxxx xxx.x °C xxx s xxxxxxxx


Diagnosis status — —

Time since engine start — —

Coolant temperature 80.0...110.0 °C ⇒ Chapter 01-5

Readiness code 00000000 ⇒ 01-7 page 7


1 2 3 4 5 6 7 8 Diagnosis function

0 Catalytic converter

0 Catalytic converter heating (no diagnosis at present/always „0“)



01-7 page 8

01

Measured value blocks, display groups 120...129 - Communication

Display group 120 - traction control system (TCS):

• Driving

Display group 122 - Gearbox (only automatic):

• Driving

Display group 125 - communication, databus messages

• Engine idling

0 Activated charcoal filter system (tank ventilation system)

0 Secondary air injection system (not fitted/always „0“)

0 Air conditioning system (currently no diagnosis/always „0“)

0 Lambda probes

0 Lambda probe heater

0 Exhaust gas recirculation



xxxx rpm xxx Nm xxx Nm Text


Status active/inactive —

Actual engine load — —

Nominal engine load — —

Engine speed xxxx rpm1)


⇒ Chapter 01-5


xxxx rpm xxx Nm xxx Nm Text


Status Engine ctl./ no ctl. —

Actual engine load — —

Nominal engine load — —

Engine speed xxxx rpm1)


⇒ Chapter 01-5



01-7 page 9

01


♦ Nominal value = 1; the control units with active data bus are displayed.


Text Text Text Text


Status airbag Airbag 1 —

Status of combiinstrument Combi 1 —

Status gearbox Gearbox 1 —

Status ABS ABS 1 —

Note



01-7 page 10

01


Repairing the injection systemEdition 06.04S00.5309.04.20

24-1 page 1

24

24-1 Repairing the injection system

Installed location overview for engines with the engine codes AUA, AUB

1 - Activated charcoal filter sys-tem solenoid valve 1 -N80- */**

inspecting ⇒ Chap. 01-1

2 - 3-pin connector for engine speed sender

-G28-

3 - Intake manifold pressure sender -G71- * with intake manifold temperature sender -G72- **

4 - Intake manifold

5 - Injector - (N30…N33)- *

6 - Knock sensor -G61- *

Fitting location: Cylinder-block intake side

inspect ⇒ Chapter 28-1

7 - Engine control unit *

8 - Throttle valve control unit -J338- *

9 - Engine speed sender -G28- *

inductive pickup Fitting location: Cylinder-

block intake side

10 - Ignition transformer -N152- *

with identification for ignition leads, do not switch


11 - 6-pin connector for wide band lambda probe

with lambda probe heating before catalyst

12 - Exhaust gas recirculation valve -N18- */** with exhaust gas recirculation potentiometer -G212- * 1.4/55; 1.4/74 Engine - Mechanics; Rep. Gr. 26

13 - Sender for coolant temperature -G62- *


14 - Hall sender - G40- *


15 - Lambda probe 1 downstream of catalytic converter -G39- *, 50 Nm Fitting location: in the exhaust manifold 6-pin connector

16 - Lambda probe 2 after catalytic converter -G130- *, 50 Nm Fitting location: downstream of catalytic converter 4-pin connector

24 – Fuel Formation, Injection

1

S24-0333D

CA

B

2

3

4 5

6 9

7 8

16

15

1413

12

11

10


Repairing the injection system Edition 06.04S00.5309.04.20

24-1 page 2

24

Installed location overview for engines with the engine codes BBY, BBZ, BKY


inspecting ⇒ Chap. 01-1

2 - 3-pin connector for engine speed sender

-G28-

3 - The vacuum regulating valve (PCV valve) for crankcase ventilation

4 - Heating resistor of crankcase ventilation -N79-


6 - Intake manifold

7 - Injectors -(N30…N33)- *

8 - Knock sensor -G61- *

Fitting location: Cylinder-block intake side


9 - Engine control unit *



inductive pickup Fitting location: Cylinder-

block intake side

12 - 6-pin connector Observe current flow dia-

gram for wide band lambda probe

with lambda probe heating before catalyst

13 - Exhaust gas recirculation valve -N18- */** with exhaust gas recirculation potentiometer -G212- * 1.4/55; 1.4/74 Engine - Mechanics; Rep. Gr. 26



15 - Hall sender -G40- *


16 - Lambda probe 1 downstream of catalytic converter -G39- *, 50 Nm pay attention to the spare part number in exhaust manifold - engines BBY, BBZ exhaust tube front - engine BKY 6-pin connector - pay attention to different connections for engines with the engine codes BKY EU-4 and EU-

2DDK 05.04

17 - Lambda probe 2 after catalytic converter -G130- *, 50 Nm Fitting location: downstream of catalytic converter 4-pin connector

18 - Ignition coils with a power output stage -N70, N127, N291 und N292- remove with extractor -T 10094-



24-1 page 3

24

General notes on the injection system

Repairing the ignition ⇒ Rep. Gr. 28.

♦ The engine control unit is equipped with a self-diagno-sis system. The first step, before commencing repairs or fault finding, is to interrogate the fault memories of all the control units using the automatic test sequence. This is necessary because different control units are interconnected via data bus. Also check the vacuum hoses and connections (unmetered air).

♦ Fuel hoses in the engine compartment must be se-cured with spring band clamps. The use of clamp-type or screw-type clips is not allowed.

♦ Switch off the ignition before disconnecting and con-necting the battery, as this may damage the 4AV con-trol unit.

♦ Components marked with an * are checked by self-di-agnosis ⇒ Chapter 01-1.

♦ Components marked with ** can be tested with the fi-nal control diagnosis ⇒ Chap. 01-1.

♦ A minimum voltage of 11.5 V is required for perfect functioning of the electrical components.

♦ Do not use sealants containing silicone. Traces of sil-icone elements drawn in by the engine are not burnt in the engine and damage the lambda probes.

♦ If after fault finding, repair or inspection of compo-nents the engine starts briefly and then stops, it is pos-sible that the immobiliser blocks the 4AV control unit. The fault memory must then be interrogated and if necessary adapted to the control unit ⇒ Chapter 24-5.

♦ Certain inspections may cause the control unit to de-tect and store a fault. It is therefore necessary to inter-rogate the fault memory after having completed all inspections and repairs, and if necessary erase ⇒ Chapter 01-1.

♦ Vehicles fitted with airbags are equipped with a crash fuel shut-off. It is intended to reduce the risk of a vehi-cle fire after a crash as the fuel pump is disconnected by the fuel pump relay. This installation also enhances the starting behaviour of the engine. When opening the door the fuel pump is activated for 2 seconds in or-der to build up the pressure in the fuel system.

Safety measures ⇒ 24-1 page 12.

Cleanliless rules ⇒ 24-1 page 13.

Inspect intake air system for leaks (unmetered air) ⇒ Chap. 24-3.

Inspecting engine operating conditions ⇒ Chapter 24-4.



24-1 page 4

24

Removing and installing parts of the injection system

1 - Plug pay attention to correct in-

stallation position

2 - Air filter disassembling and assem-

bling ⇒ 24-1 page 11

3 - Cable guide clipped on to fuel rail

4 - 10 Nm5 - Vent valve6 - Fuel rail with injection valves

disassembling and assem-bling ⇒ 24-1 page 10

7 - 20 Nm8 - from brake servo unit9 - Connector

6-pin for throttle valve control unit

-J338- Contacts of connector gold-

plated


⇒ 1.4/55; 1.4/74 Engine - Mechanical Components; Rep. Gr. 20

11 - Intake manifold disassembling and assem-

bling ⇒ 24-1 page 6

12 - Gasket replace

13 - 10 Nm14 - Connecting tube

to exhaust gas recirculation valve

15 - Lambda probe 2 after catalytic converter -G130- *, 50 Nm coat only thread with hot bolt paste -G 052 112 A3-; paste must not get into the slot of the probe body with 4-pin connector Contacts 3 and 4 gilded Power supply for lamda probe heating supplied via fuel pump relay -J17- Testing lambda probe and lambda control downstream of catalytic converter ⇒ Chapter 24-4 Test lambda probe heater downstream of catalytic converter ⇒ Chapter 24-4 Fitting location: downstream of main catalytic converter

16 - Connector for lambda probe downstream of catalytic converter 4-pin

17 - Lambda probe 1 upstream of catalytic converter -G39-*, 50 Nm coat only thread with hot bolt paste -G 052 112 A3-; paste must not get into the slot of the probe body pay attention to the spare part number with 6-pin connector contacts gold-plated Power supply for lamda probe heating supplied via fuel pump relay -J17- Testing lambda probe and lambda control upstream of catalytic converter ⇒ Chapter 24-4 Testing lambda probe heater upstream of catalytic converter ⇒ Chapter 24-4 Fitting location: Engines BBY, BBZ in the exhaust manifold, engine BKY in the front exhaust pipe

13

S24-0338

12

11

10

9

76

4

2

1415161718

19

2021

22232425 26

22272628

30

31

32

33

29

1

5

3

8



24-1 page 5

24

18 - Connector for lambda probe upstream of catalytic converter 6-pin - pay attention to different connections for engines with the engine codes BKY EU-4 and EU-2DDK

05.04



20 - 5 Nm21 - Gasket

replace

22 - Retaining clip check tightness

23 - Connector black, 2 pin for sender for coolant temperature -G62- contacts gold-plated


before removing, reduce pressure in cooling system inspect ⇒ Chapter 24-2

25 - Plug before removing, reduce pressure in cooling system

26 - O-ring replace if damaged

27 - 10 Nm28 - Coolant regulator housing29 - Fuel-intake hose

secure with spring strap clamps check for firm seating from fuel filter ⇒ 1.4/55; 1.4/74 Engine - Mechanical Components; Rep. Gr. 20

30 - Connector for engine control unit insert or remove only when the ignition is switched off

31 - Engine control unit* testing voltage supply ⇒ Chapter 24-5 Procedure to follow after power supply interruption has occurred ⇒ Chapter 24-5 replacing ⇒ Chapter 24-5 coding ⇒ Chapter 24-5 Fitting location ⇒ 24-1 page 1, overview of the engine compartment

32 - Retaining frame33 - 2 Nm



24-1 page 6

24

Disassembling and assembling intake manifold

Engines with engine codes AUA and BBY; vehicles mit engines BBY and manual gearbox 08.03


inspect ⇒ Chapter 24-2 if replaced adapt engine con-

trol unit ⇒ Chapter 24-5 if replaced adapt automatic

gearbox control unit ⇒ chap. 24-5

2 - 10 Nm3 - Gasket

Check fitting position replace

4 - Induction pipe5 - Gasket ring

replace if damaged

6 - 20 Nm7 - Gasket ring

replace

8 - Guide plate pay attention to correct in-

stallation position replace if damaged


10 - 3 Nm11 - Intake manifold pressure

sender -G71- * with intake manifold temperature sender -G72- **

Testing intake manifold pres-sure sender ⇒ Chap. 24-2

Inspecting intake manifold temperature sender ⇒ Chap. 24-2

12 - Intake manifold out of plastic pay attention to the spare part number removing and installing ⇒ 24-1 page 4



24-1 page 7

24

Engines with engine code AUB



trol unit ⇒ Chapter 24-5

2 - Gasket ring replace if damaged

3 - 10 Nm4 - 20 Nm5 - Intake manifold

Aluminium casting pay attention to the spare

part number removing and installing

⇒ 24-1 page 4

6 - Gasket ring replace







10 - 3 Nm



24-1 page 8

24

Engines with engine codes BBZ; vehicles mit engines BBY and manual gearbox 09.03

1 - Intake manifold out of plastic pay attention to the spare


⇒ 24-1 page 4



trol unit ⇒ Chapter 24-5


replace if damaged


replace




9 - 3 Nm10 - Intake manifold pressure

sender -G71- * with intake manifold temperature sender -G72- **





24-1 page 9

24

Engines with engine identification letters BKY

1 - Intake manifold out of plastic pay attention to the spare


⇒ 24-1 page 4



trol unit ⇒ Chapter 24-5 if replaced adapt automatic

gearbox control unit ⇒ chap. 24-5

3 - 7 Nm4 - Gasket

replace if damaged


replace







24-1 page 10

24

Disassembling and assembling fuel distributor with injectors

1 - Fuel-intake hose secure with spring strap

clamps check for firm seating

2 - 10 Nm3 - Fuel distributor4 - Vent valve5 - Retaining clip

check tightness on the injec-tion valve and fuel distributor

6 - O-ring replace before fitting moisten lightly

with clean engine oil

7 - Injector -N30-…-N33- *

inspect ⇒ Chapter 24-3 Resistor 14...17 Ω at 20 °C

Removing

– Unplug connector -arrows- of the injectors.

1

S24-0339

2 3 2

5

6

7

6

5

7

4



24-1 page 11

24

– Pull out the fuel feed hose -arrow- and catch the fuel which flows out with a cleaning cloth.

– Remove the fuel distributor with injectors from the inlet manifold.

Installing

– Installation is carried out in the reverse order.

♦ Replace O-rings.

♦ before fitting moisten O-rings lightly with clean engine oil

Disassembling and assembling the air filter

1 - Air filter top part2 - Gasket

replace if damaged

3 - Filter insert4 - Air filter bottom part5 - Rubber holder6 - 3 Nm7 - Gasket ring

check for firm seating replace if damaged

8 - Inlet connection with control flap Inspecting intake manifold

preheating ⇒ Chapter 24-3

S10-0099

WARNING!

The fuel system is under pressure! Before opening the system lay cleaning cloths around the connec-tion point. Reduce pressure by carefully releasing the connection point.

Note

1

8

6

5

54 6 7

2

3

S24-0331



24-1 page 12

24

Fig. 1: Resistance values for the coolant tempera-ture sender -G62-

The diagram is divided into two temperature ranges:

A - from 0...50 °CB - from 50...105 °C

Read out examples:

♦ 30 °C is in range A and corresponds to a resistance of 1.5...2.0 kΩ

♦ 80 °C is in range B and corresponds to a resistance of 275...375 Ω

Fig. 2: Resistances for intake manifold pressure sender -G72-

The diagram is divided into two temperature ranges:

A - from 0...50 °CB - from 50...105 °C

Read out examples:

♦ 20 °C is in range A and corresponds to a resistance of 2.3...2.6 kΩ

♦ 80 °C is in range B and corresponds to a resistance of 290...330 Ω

Fig. 3: Removing and installing an engine cover with air filter

Removing

– Pull off hose -1- (engines 04.02 ) and remove en-gine cover -2- with air filter upwards -arrows-.

Installing

– Installation of the engine cover with air filter occurs in reverse order.

Safety measures

Observe the following points to prevent injury to persons and/or damage to the injection and ignition system:

WARNING!

The fuel system is under pressure! Before opening the system lay cleaning cloths around the connec-tion point. Reduce pressure by carefully releasing the connection point.



24-1 page 13

24

♦ For reasons of safety fuse no. 40 must be removed from the fuse holder before opening the fuel system, as the door contact switch could activate the fuel pump.

♦ Do not touch or remove ignition leads with the engine running or at start speed.

♦ Ignition must be switched off before disconnecting and re-connecting cables of the fuel injection and igni-tion system as well as of test equipment.


♦ Always secure the test and measuring devices on the rear seat and also have a second person operate them there.


♦ If the engine must be operated at start speed without the engine starting:

For engines with the engine codes AUA, AUB

– Unplug the 4-pin connector -arrow- from the ignition transformer.

For engines with the engine codes BBY, BKY, BBZ

– Pull out all ignition coils using the extractor -T 10094-.

For all vehicles


Rules of cleanliness

When working on the fuel supply/fuel injection system, pay careful attention to the following „5 rules“ for cleanli-ness.

♦ Thoroughly clean the connection points and their sur-roundings before releasing.

♦ Place removed parts on a clean surface and cover. Do not use fuzzy cloths!

♦ Carefully cover or close opened components if the re-pair is not completed immediately.

♦ Only install clean parts. Remove spare parts from their wrapping immediately before fitting. Do not use any parts which have been stored unwrapped, e.g. on a shelf or in a tool box.

♦ When the system is open: avoid working with com-pressed air. Avoid moving the vehicle.



24-1 page 14

24


Testing componentsEdition 06.04S00.5309.04.20

24-2 page 1

24

24-2 Testing components

Testing throttle valve control unit

Components for throttle valve control unit -J338-: Throttle valve drive -G186-, throttle valve drive angle sender 1 -G187- and throttle valve drive angle sender 2 -G188-.

♦ If the throttle valve control unit is replaced, it is then essential to adapt this new throttle valve control unit to the engine control unit ⇒ Chap. 24-5.

♦ On vehicles with an automatic gearbox the gearbox control unit must also be replaced ⇒ Chap. 24-5.



♦ Test box -V.A.G 1598/31-

♦ Handheld multimeter, e.g. -V.A.G 1526 B-

♦ Measuring tool set e.g. -V.A.G 1594 C-


Test condition

• Throttle valve is not damaged or dirty.

Test sequence

– Unplug the 6-pin connector from the throttle valve control unit.

– Measure resistance of throttle valve drive between contacts 3 + 5.

Specified value: 3...200 Ω

If the specified value is not reached:

– Replace throttle valve control unit -J338-.

If the specified value is reached:

– Test voltage supply of throttle valve control unit and cables to engine control unit ⇒ 24-2 page 1.

If the power supply and wiring is O.K.:


Testing voltage supply and wiring to the control unit

– Unplug the 6-pin connector from the throttle valve control unit.

– Connect the multimeter for voltage measurement to contacts 2 + 6 of the connector.

– Switch on ignition.

Note


Testing components Edition 06.04S00.5309.04.20

24-2 page 2

24

Specified value: min. 4,5 V


– Connect the multimeter for voltage measurement to contact 2 of the connector and to earth.





– Connect test box -V.A.G 1598/31- to wiring loom of control unit ⇒ Chapter 24-5. The engine control unit is not connected here.

– Check wiring between the test box and the 6-pin plug for interruption:

Line resistance: max. 1.5 Ω

– Test the cables for short circuiting with each other.



– Inspect engine control unit power supply ⇒ Chapter 24-5.

Testing accelerator pedal position send-er





♦ Test box -V.A.G 1598/31-


Operation

The two accelerator pedal position senders -G79- and -G185- are located at the accelerator pedal and pass on the driver input to the engine control unit completely inde-pendently of each other (when accelerator is depressed). Both senders are located in a housing.

Plug contact Test box bush -V.A.G. 1598/31-

1 92

2 83

3 117

4 84

5 118

6 91



24-2 page 3

24

Test condition

• Battery voltage at least 11.5 V.

Test sequence

– Connect vehicle system tester -V.A.G 1552-. Switch ignition on and select address word 01 „Engine elec-tronics“ ⇒ Chap. 01-1.

– Select function 08 „Read measured value block“ and display group 062.

– Test the nominal value of sender 1 -G79- at idle stop in display field 3:

Specified value: 3...100 %

– Test the nominal value of sender 2 -G185- at idle stop in display field 4:

Specified value: 3...100 %

The engine control unit converts the voltage values of the throttle valve drive angle sender in percentage (in relation to 5 Volts) (5 Volts power supply correspond to 100%).

– Slowly press the accelerator pedal while observing the values in the display fields 3 and 4.

Sollwert: 3…100 %


– Test the voltage supply and the wiring of the acceler-ator pedal position sender ⇒ 24-2 page 3.


Testing voltage supply and wiring to the control unit

– Remove storage compartment on driver side ⇒ Body Fitting Work; Rep. Gr. 68.

– Disconnect the 6 pin plug connection from the accel-erator pedal position sender.


– Connect the multimeter for voltage measurement to the following contacts of the connector:

Contact 1 + earth

Contact 1 + 5

Contact 2 + earth

Contact 2 + 3




Reading measured value block 62 -> 2% 2% 14% 14%

Note



24-2 page 4

24


– Check wiring between the test box and the plug for in-terruption according to the Current Flow Diagram:





– Replace accelerator pedal position sender.

Testing the intake manifold pressure sender

Only use gilded contacts to repair contacts in the plug connection of the sender.



♦ Test box -V.A.G 1598/31-




Test sequence



– Read off intake manifold pressure values indicated in display field 2.

Specified value: 240…420 mbar

– Briefly open throttle valve. The intake manifold pres-sure value in display field 2 must increase briefly.


1 72

2 73

3 36

4 35

5 33

6 34

Note

Reading measured value block 3 -> 840/min 365mbar 2



24-2 page 5

24

If 91 mbar or 1254 mbar is always indicated:

Continuation of the test if the display reads 91 mbar:

– Disconnect the 4-pin plug connection from the intake manifold pressure sender - G71- with intake manifold temperature sender -G72- -arrow- (engine may stall).

– Bridge contacts 3 + 4 of the plug connection and ob-serve the read-out on the display.

If the display jumps to 1254 mbar:


– Replace the intake manifold pressure sender -G71- with intake manifold temperature sender -G72- ⇒ Chap. 24-1.

If the display remains at 91 mbar:



– Check wiring between the test box and the 4-pin plug for interruption according to the Current Flow Dia-gram.


– Also test wire contact 4 for short-circuit to earth and to contact 1.




Display Cause Continue test

91 mbar Line interruption or short-circuit to

earth

⇒ 24-2 page 5

1254 mbar Short circuit to positive

⇒ 24-2 page 6


3 98

4 109



24-2 page 6

24

Continuation of the test if the display reads 1254 mbar:

– Disconnect the 4-pin plug connection from the intake manifold pressure sender - G71- with intake manifold temperature sender -G72- -arrow- (engine may stall).

If the display jumps to 91 mbar:



If the display remains at 1254 mbar:


– Unlock connector at control unit and unplug.

– Check the wires for plug of control unit at 4-pin plug contact 4 for short-circuit to wire contact 3 as well as after positive battery.




Testing intake manifold temperature sender

Only use gilded contacts to repair contacts in the plug connection of the sender.


♦ Vehicle system tester e.g. -V.A.G 1552- with cable -V.A.G 1551/3, 3A, 3B, 3C-

♦ Test box -V.A.G 1598/31-




Test sequence



– Read off intake manifold temperature value in display field 4.

Specified value: Ambient temperature1)

1) If a temperature is displayed that is below the ambient temperature of the sender, check the sender wires for transition impedances. Make sure that the sender heats up or is heated by radiant heat.

Note

Reading measured value block 4 -> 840 rpm 13.6V 91 C 62 C



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If implausible value appears in the display:


– Disconnect the 4-pin plug connection from the intake manifold temperature sender -G72- with intake mani-fold pressure sender -G71- -arrow-.

– Connect the multimeter for resistance measurement to contacts 1 and 2 of the intake manifold temperature sender.

Specified value:

The nominal value in field A applies for temperature range 0...50 °C, nominal value in field B applies for tem-perature range 50...105 °C.

Example:

♦ For a temperature of 20 °C the specification is 2.3...2.6 kΩ

♦ For a temperature of 80 °C the specification is 290...330 Ω







– Additionally check the cable for a short circuit to bat-tery positive.





1 108

2 85



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Testing coolant temperature sender

Special tools, test and measuring equipment and aids required

♦ Vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3, 3A, 3B, 3C-

♦ Test box -V.A.G 1598/31-




Test sequence



– Read off coolant temperatur value indicated in display field 2.

Specified value: Coolant temperature

If implausible value appears in the display:


– Unplug the 2-pin plug for the coolant temperature sen-sor -G62- -arrow-.

– Connect the multimeter for resistance measurement to contacts 1 and 2 of the coolant temperature sender.

Specified value:

The nominal value in field A applies for temperature range 0...100 °C, nominal value in field B applies for tem-perature range 50...105 °C.

Example:




– Replace the coolant temperature sender -G62- ⇒ Chapter 24-1



Reading measured value block 1 -> 840/min 88 C 4.0% 00111111

S24-0349



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– Additionally check the cable for a short circuit to bat-tery positive.




S24-0341

21


1 93

2 108



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24-3 Testing components I

Test engine speed sender

The engine speed sender -G28- is a speed and reference marking sender. If the speed signal fails with the engine running this could result in an engine stoppage.


♦ Test box -V.A.G 1598/31-




Test condition


Test sequence

– Disconnect the 3-pin plug connection from the engine speed sender -G28- ⇒ Chap. 24-1.

– Connect the multimeter for voltage measurement to contact 1 (positive) and 3 (earth) of the plug for engine speed sender.


Specified value: min. 4.5 V


If no voltage is present:






If no fault was detected in the wiring and if there was no voltage between contact 1 + 3:

– Replace engine speed sender -G28- ⇒ Chapter 24-1.

V


1 87

2 82

3 108


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Testing injection valves

Test control


♦ Test box -V.A.G 1598/31-


♦ Diode test lamp e.g. -V.A.G 1527-



♦ Extractor -T 10094-

Test conditions

• Fuse 35 must be OK

• Earth connections between the engine (on gearbox housing) and body (under battery) are o.k.


• Engine speed sender o.k.; check ⇒ 24-3 page 1.

• Check that the Hall sender is o.k. ⇒ Chapter 28-1.

• Fuel pump relay OK

Test sequence


Engines with the engine codes AUA, AUB


Engines with the engine codes BBY, BBZ, BKY

– Pull out all ignition coils using the extractor -T 10094-.

For all vehicles

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– Connect up the diode test lamp to the contacts of the plug for cylinder 1.

– Actuate the starter and check the power supply to the injection valve of cylinder 1.

LED must flash.

– Repeat test on the plug connections for the injection valves on cylinder 2 to 4.


If the LED does not light up on any cylinder:

– Connect the diode test lamp to the plug connection on cylinder 1, contact 1 and earth.

– Actuate the starter and check the power supply to the injection valve of cylinder 1.

LED must flash.

– Repeat test on the plug connections for the injection valves on cylinder 2 to 4.

If the LED does not flash:




If the LED does not light up on one or more cylinders:

1

2 S24-0344

1

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– Check wiring between the test box and the 2-pin plugs on the injection valves for interruption according to the Current Flow Diagram.




– Check wiring between contacts 1 of the plug connec-tion on the injection valves for interruption of each oth-er.


Testing resistances of the injection valves

Test sequence

– Check resistance of the individual injection valves.

Specification at 20 °C: 14,0...17,0 Ω

If the engine is warm the resistance increases by approx-imately 4 to 6 Ω.


– Replace the defective injection valve ⇒ Chapter 24-1.

Test spray pattern, leak tightness and injected quantity


♦ Torque wrench

♦ Measuring tool set, e.g. -V.A.G 1594 C-

♦ Remote control, e.g. -V.A.G 1348/3 A-

♦ Adapter, e.g. -V.A.G 1348/3-2-

♦ Digital potentiometer, e.g. -V.A.G 1630-

♦ Measuring vessel, for example -V.A.G 1602-

1 2

S24-0343

Injector Plug contact Test box bush -V.A.G 1598/31-

1 2 96

2 2 97

3 2 88

4 2 89



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Test conditions

• The fuel pressure must be OK, test it ⇒ 1.4/55; 1.4/74 Engine - Mechanics; Rep. Gr. 20.

• Fuel pump relay o.k., testing ⇒ Chap. 01-1, final con-trol diagnosis.

• Fuel temperature 15... 20 °C, the fuel must conform to the valid standards.

Test sequence


– Completely remove the fuel rail with all injection valves from the intake manifold (the fuel hose remains connected) ⇒ Chapter 24-1.

Testing jet formation and tightness

– Unplug the 2-pin plug for the coolant temperature sen-sor -G62- -arrow-.

– Connect up digital potentiometer V.A.G -1630- to con-tacts 1 + 2 of the plug connection and set the connect-ed side to 15 kΩ.

S24-0349

V.A.G 1630

2

1

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– Hold measuring vessel under the injection valve to be tested and disconnect the plug on the other injection valves.

– Have a 2nd mechanic actuate the starter. The injec-tion valve must emit a pulsed jet of fuel.

– Repeat test at the other injectors. Make sure that only the valve to be tested is connected.

The jet must be the same for all valves.

– Then check the injection valve for leaks. No more than 2 drops/min may trickle out.

If the fuel loss is greater than this:



Testing fuel injected quantity

When testing the injection rate also check the jet forma-tion. The jet must be the same for all injection valves.

– Insert injector to be tested in a measuring glass, e.g. -V.A.G 1602-.

– Connect a contact of the injector to be tested with adapter cables to the battery earth.

– Connect the second contact of the injector to be test-ed with remote control and adapter cable to positive battery.

– Connect battery positive (+) and fuse socket No. 61 with adapter cable and adapter -V.A.G 1348/3-2-.

The fuel delivery unit must start running.

– Activate remote control for 30 seconds.

– Repeat the measurement on all injectors. Always use a new measuring glass.

– After the measurement of all valves, deactivate the voltage supply of the fuel delivery unit.

– Place the measuring glasses on a flat surface and compare the quantities of fuel injected.

Nominal value per injection valve:

1.4/55 kW Engine: 57 ... 65 ml

1.4/74 kW Engine: 88 ... 98 ml

If the measurement obtained for one injector is not within the specification:


The injectors are installed in the reverse order for remov-al. Pay attention to the following:

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Note

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♦ Replace the O-rings on all the injectors and moisten lightly with clean engine oil.

♦ Fit the fuel rail with the installed injection valves to the intake manifold and tighten screws uniformly to 10 Nm.

Testing the intake system for tightness (unmetered air)

Testing with engine leak search spray



♦ Engine leak search spray (e.g. G 001 800 A1)

Test condition

• Coolant temperature must be at least 80 °C ⇒ Chapter 01-5 display group 001, display field 2.

Test sequence

♦ Because of the vacuum in the intake system the leak search spray is sucked in with the unmetered air. The leak search spray reduces the ignition performance of the mixture. This results in a drop in engine speed and a change in the lambda probe voltage.

♦ You must comply with the safety instructions on the box.



– Observe the control value in display field 1.

– Systematically spray parts of the intake system with engine leak search spray.

If the engine speed drops or if the control values chang-es:

– Check the sprayed location of the intake system for leaks and if necessary eliminate the fault.

If the engine speed or control value does not change:


Note

Reading measured value block 33 ->2.0% 0.462V



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Testing intake manifold preheating


♦ Cooling spray

Testing control flap

– Remove air filter ⇒ Chap. 24-1.

– Check position of the regulating flap -1-.

♦ Above +23 °C the flap must close the hot air connec-tion

♦ Below +10 °C the flap opens the hot air connection.

Operation of the thermo-element -2- can easily be tested by spraying on a cooling spray.

Idle testing

♦ The idling speed, ignition point and CO content are only measured as they cannot be adjusted.

♦ The idling speed is set to nominal value by the throttle valve positioner together with the DLS function.

♦ The CO content is set to nominal value by the lambda control. Faults in the lambda control are detected by the self-diagnostic system and stored in the fault memory.



Test conditions

• The exhaust system between the cylinder head and the catalyst must be tight.

• Coolant temperature at least 80 °C ⇒ Chapter 01-5 display group 004, display field 3.

• All electrical components such as lights and rear win-dow heater must be switched off.

• If vehicle is equipped with air conditioning, this must be switched off.


Test sequence


S24-0332

1

2

Note

Note



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– Interrogate fault memory, rectify any faults and then erase the fault memory ⇒ Chapter 01-1.

Testing idling speed


– Check the operating condition in indicator field 4.

Specified value: 00000 (meaning ⇒ Chapter 01-7).

– Check nominal idling speed in display field 2.

Specified value:

Vehicles with engine code AUA: 750 rpm

Vehicles with the engine codes BBY, BKY: 760 rpm

Vehicles with automatic gearbox (engine codes AUA, BBY, BKY): 680 rpm

Vehicles with engine code AUB: 840 rpm

Vehicles with engine code BBZ: 680 rpm

The idling speed of the engine is increased if the battery is heavily discharged or the engine is extremely overheat-ed.

– Check idling speed in display field 1.

Specified value:

Vehicles with engine code AUA: 650 ... 850 rpm1)

Vehicles with the engine codes BBY, BKY: 660 ... 860 rpm1)

Vehicles with automatic gearbox 580... 780 rpm1)

Vehicles with engine code AUB: 740 ... 940 rpm1)

Vehicles with engine code BBZ: 580 ... 780 rpm1)


If the idling speed is not reached:

– Adapt engine control unit to throttle valve control unit ⇒ Chapter 24-5.

– Perform a test drive.

– Interrogate the fault memory on the control unit again.

– Repeat idling speed test.

If the nominal values are again not reached:

– Test throttle valve control unit ⇒ Chapter 24-2.

– Inspecting engine operating conditions ⇒ Chapter 24-4.

– Testing intake system for tightness ⇒ Chap. 24-3.

1) Current value ⇒ Inspection and Maintenance.

Reading measured value block 56 ->750/min 750/min 5Nm 00000

Note



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24-4 Testing components II

Test lambda probe heating before cata-lyst



♦ Test box -V.A.G 1598/31-




Test conditions

• Fuses No. 3 and 9 must be O.K.


• The fuel pump relay must be OK.

Test sequence


Engine idling.


– Check status of the lambda probe heater in display field 2.

Specified value: „Ht. before c. ON“.

Depending on the operating state of the engine the lamb-da probe heaters are switched on or off, i.e. the readouts in display field 2 may show either „Htg. before C.ON“ or „Htg. before C.OFF“.


– Remove the 6-pin plug -arrow- to the lambda probe before the catalyst -G39-.

Depending on the lambda probe version, the heater can be connected to contacts 1 + 2 or 3 + 5 of the 6-pin plug (only on engines with code letters BKY EU-4 and EU-2DDK 05.04 ; the instructions for these engines are list-ed below in the brackets).

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Reading measured value block 41 ->Ht. before c. ON 15 Ohm Ht. after c. ON

Note

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– Check probe heater at connector for lambda probe, contact 1 + 2 (3 + 5) for continuity.

At ambient temperature the resistance of the heating ele-ment should be approx. 1...5 . The resistance increases considerably even if the temperature rises only slightly.

If there is an interruption in the lambda probe heating:

– Replace lambda probe upstream of the catalyst -G39-.

If the probe heating has continuity:

– Switch the multimeter to voltage measurement and connect it to contacts 1 + 2 (3 + 5) of the connector to the engine control unit.

– Start engine and run in idle.

– Measure the voltage supply and at the same time ob-serve display group 041, display field 2.

Display: „Ht. before c. ON.“

Specified value: 11.0...14.5 V

or

Display: „Ht. bf. c. ON“/„Ht. bf. c. OFF“ (alternately)

Specified value: fluctuating between 0...14.5 V





Specified value - line resistance: max. 1.5 Ω


– Check wiring from contact 2 (5) to fuel pump relay -J17- according to the Current Flow Diagram ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Locations.

If wiring is o.k.:


2S24-0346

4 6

3 51

Note


1 (3) 5



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Testing lambda probe and lambda con-trol upstream of catalytic converter



♦ Test box -V.A.G 1598/31-




Test conditions

• Coolant temperature at least 80 °C ⇒ display group 004, display block 3.

• The exhaust system must be tight between the cata-lyst and the cylinder head.

Check for proper operation



– Check status of the lambda control before catalyst (display field 1):



The first digit of the 3-digit numerical block (heating) fluc-tuates between 0 and 1.


– Test lambda probe heating before catalyst ⇒ 24-4 page 1.



– Blip 2 accelerations above 5000 rpm.

Reading measured value block 30 ->111 110


1 2 3

1 Lambda control active



Note

System in basic setting 34 ->2350/min 244.0 C 0.25s Test ON



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– Set engine speed to 1500...3900 rpm.

– Maintain speed until „Test ON“ is displayed in display field 4.

– Run engine at this speed until display field indicates specified value „B1-S1 O.K.“.

If „B1-S1 nok“ is shown in display field 4:

– Press key.


– Observe lambda control in display field 1. The readout must fluctuate in the region from -10.0...10.0 %.

– Read off voltage in display block 2. The voltage must oscillate at least 20 times per minute in the region be-tween 0 to 1.0 V.

If the display in display field 2 remains constantly on one value:

– Continue test according to the following table:

If the lambda control in display field 1 does not oscillate in the given region:


– Conduct test drive and repeat test.

Comply with the applicable safety instructions for a test drive ⇒ Chap. 24-1.

If the nominal value in display field 1 is still not reached after a test drive or if the value does not fluctuate by at least 2 %:

– Test basic voltage.

Test basic voltage

– Remove the 6-pin plug to the lambda probe before the catalyst -G39-.

Depending on the wide-band lambda probe version, it can be connected to contacts 3+ 4 +5 + 6 or 2 + 1 + 4 + 6 of the 6-pin plug (only on engines with code letters BKY EU-4 and EU-2DDK 05.04 ; the instructions for these engines are listed below in the brackets).

Reading measured value block 33 ->2.0% 0.462 V


between 0.400 .... 0.500 V

Open circuit Check voltage ⇒ 24-4 page 4

1.105 V Short circuit to posi-tive

Check lambda probe wiring

⇒ 24-4 page 40.000 V Short circuit to earth

S24-0347

Note



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– Connect the multimeter for voltage measurement to contacts 3 + 4 (2 + 1) of the connector at the engine wiring harness.

– Switch on ignition and measure voltage.






– Check lambda probe wiring.

Check lambda probe wire upstream of catalytic converter




– Check wiring at plug contact 3 + 4 (2 + 1) for short-cir-cuit to contact 1 + 2 (3 + 5).



Test lambda probe heating after catalyst



♦ Test box -V.A.G 1598/31-

♦ Handheld multimeter, e.g. -V.A.G 1526.A-




3 (2) 52

4 (1) 71

5 (4) 70

6 (6) 51



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Test conditions

• Fuses No. 3 and 9 must be O.K.


• The fuel pump relay must be OK.

Test sequence



– Check status of the lambda probe heater in display field 4.

Specified value: „Ht. after c. ON“.

Depending on the operating state of the engine the lamb-da probe heaters are switched on or off, i.e. the readouts in display field 4 may show either „Htg. after C.ON“ or „Htg. after C.OFF“.


– Remove the 4-pin plug to the lambda probe -G130- -arrow-.

– Check probe heater at connector for lambda probe, contact 1 + 2 for continuity.

At ambient temperature the resistance of the heating ele-ment should be approx. 1...5 . The resistance increases considerably even if the temperature rises only slightly.

If there is an interruption in the probe heating:

– Replace lambda probe after catalyst -G130-.

If the probe heating has continuity:

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Reading measured value block 41 ->Ht. before c. ON 15 Ohm Ht. after c. ON

Note

S24-0348

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– Connect multimeter for voltage measurement to con-tacts 1 + 2 (plug at engine wiring harness).

– Start engine and run in idle.

– Measure the voltage supply and at the same time ob-serve display group 041, display field 4.

Display: „Ht. after c. ON“


or

Display: „Ht. after c. ON“ / „Ht. after c. OFF“ (alternately)

Specified value: fluctuating between 0.0....14.5 V








If wiring is o.k.:


Testing lambda probe and lambda con-trol after catalyst



♦ Test box -V.A.G 1598/31-




Test conditions

• The coolant temperature must be at least 80°C, ⇒ display group 004, display field 3.


V


2 63



24-4 page 8

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– Check status of the lambda control after catalyst (dis-play field 2):


The 3rd bit in display field 2 is only set to 1 under partial load (2500...4000 rpm).


♦ The lambda control of the lambda probe after catalyst (B1-S2) is inactive without load.

♦ The first digit of the 3-digit numerical block (heating) fluctuates between 0 and 1.


– Test lambda probe heating after catalyst ⇒ 24-4 page 5.



– Depress brake pedal and hold pressed. The speed automatically increases.

„ B1-S2 O.K.“ appears in display field 2.

If „B1-S2 n.o.k“ is shown in display field 2:

– Test lambda probe voltage 2 at idle in display field 1.

Specified value: 0,000…1.000 V

– Continue test according to the following table:

Reading measured value block 30 ->111 110

Note


1 2 3

x Lambda control active; specified value: 1/0



Note

System in basic setting 36 ->0.856 V Test ON



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If the lambda control in display field 1 does not oscillate in the given region:


– Conduct test drive and repeat test.


If the nominal value in display field 1 is still not reached after a test drive or if the value does not fluctuate by at least 2 %:

– Test basic voltage.

Test basic voltage

– Remove the 4-pin plug to the lambda probe -G130- -arrow-.

– Connect multimeter for voltage measurement to con-tacts 3 + 4 (plug at engine wiring harness).

– Switch on ignition and measure voltage.

Specified value: 0,40…0.50 V



– Replace lambda probe after catalyst -G130-.


– Check lambda probe wire downstream of catalytic converter.

Check lambda probe wire downstream of cata-lytic converter




between 0.400.... 0.500 V

Open circuit Check voltage ⇒ 24-4 page 9

1.105 V Short circuit to positive Check lambda probe wiring

⇒ 24-4 page 90.000 V Short circuit to earth

S24-0348


3 68

4 69



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– Check wiring of contact 3 + 4 of the plug for short-cir-cuit to contact 1 + 2.



Check lambda probe ageing before cata-lyst



Test conditions






– Blip 2 accelerations above 5000 rpm.

– Set engine speed to 1500...3900 rpm.

– Maintain this speed until the value in display field 4 jumps from „Test ON“ to „B1-S1 o.k.“.

This may take a few mlnutes.

– Check period in display field 3:

Specified value: maximum 1.0 s

– Maintain the speed at 1500...3900 rpm until display field 4 indicates nominal value „B1 S1 O.K.“.



– Conduct a test drive in order to eliminate any residues on the lambda probe and repeat the test.


If the specified value is again not reached:


System in basic setting 34 ->2300/min 244.0 C 0.25s Test ON

Note



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Testing the engine operating conditions

Test whether the engine control unit detects the operating conditions idling, trailing throttle, partial load, enrichment and full load of the engine.



Test condition


Test sequence



– Test whether the control unit recognizes the operating conditions (display field 4):

♦ Idling

As long as the engine is idling, the following must be dis-played: Idling.

♦ Trailing throttle

– Engine speed must increase to more than 3000 rpm.

– Suddenly close the throttle valve.

As long as the speed is above 1400 rpm the following must be displayed. Trailing throttle.

Once engine speed is below 1400 rpm idling is again dis-played.

♦ Partial load

– Accelerate constantly.

As long as the acceleration is constant the following must be displayed: Partial load.

♦ Enrichment

– Push the accelerator pedal down sharply to the stop.

When accelerating the following must be briefly dis-played: Enrichment.


Note

Reading measured value block 5 -> 840/min 20% 0km/h Idling

Note



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– Interrogate fault memory, rectify any faults and erase fault memory ⇒ Chap. 01-1.

– Test throttle valve control unit ⇒ Chapter 24-1.


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24-5 Engine control unit

Wiring and Component Test with Test Box V.A.G. 1598/31


♦ Test box -V.A.G 1598/31-

♦ The test box -V.A.G 1598/31- is designed in such a way that it can be simultaneously connected to the wiring loom of the engine control unit and to the actual engine control unit.

♦ The advantage being that the electronic engine con-trol remains fully operational with the test box con-nected (e.g. measuring signals while the engine is running).

♦ Whether the control unit remains connected to the test box or not, is described in the relevant test proce-dures.

♦ The contact numbers of the connector of the control unit and the socket numbers of the test box are iden-tical.


– Release the connector catches and unplug the control unit connectors.

– Connect test box -V.A.G 1598/31- to connector of wir-ing loom. The earth clip of the test box must be con-nected to the negative battery terminal.

– Perform test as described in the relevant repair se-quences.

Testing voltage supply for engine con-trol unit



♦ Test box -V.A.G 1598/31-




Note

V.A.G. 1598/31

S01-0089

DANGER!

To avoid damaging the electronic components, switch on the relevant measuring range before connecting the measuring cables and comply with the test conditions.


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Test conditions


• Fuses No. 3, 14, 17, 48, and 56 must be OK.

• AC generator o.k., test: ⇒ Electrical system; Rep. Gr. 27.

Test sequence



– Read off readout in display field 2.




– Connect test box -V.A.G 1598/31- to connector of wir-ing loom ⇒ 24-5 page 1. The engine control unit is not connected here.

Testing voltage of terminal 30

– Measure supply voltage between sockets 1 + 3 of the test box:



– Test cable connections to relay plate according to the current flow diagram ⇒ Current Flow Diagrams, Elec-trical Fault Finding and Fitting Locations.

Testing voltage of terminal 15

– Use multimeter to measure voltage between sockets 2 + 4 at the test box.




– Test cable connections to relay plate according to the current flow diagram ⇒ Current Flow Diagrams, Elec-trical Fault Finding and Fitting Locations.

Procedure after voltage supply has been interrupted

If the power supply is interrupted the engine control unit forgets all initialisation or basic setting values and the Readiness Code is erased. Depnding on the mileage

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Reading measured value block 4 ->840 rpm 13.6V 91 C 62 C



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which the vehicle has driven, this may result in consider-able driveability problems.



Procedure

After the voltage supply has been interrupted, it is neces-sary to carry out the following steps:

– Switch ignition on for at least 10 seconds.

– Switch ignition off for at least 30 seconds.

– Adapt engine control unit to throttle valve control unit ⇒ 24-5 page 6.

– Performing idling test ⇒ Chap. 24-4.

On vehicles with an automatic gearbox the gearbox con-trol unit must also be adapted.

– Conduct a lengthy test drive until the problems have been rectified.



♦ After reaching the corresponding temperature, the fol-lowing operating conditions must be reached a number of times: Idling, part load, full load, overrun.


Replacing engine control unit



Procedure

– Enter the control unit identification and thus also the coding of the previous control unit as follows:


The control unit identification number and the coding are shown on the display, e.g.:

036906034T MARELLI 4LV 2615 ->Coding 00031 WSCXXXXX



24-5 page 4

24


– Release the connector catches and unplug the con-nector -arrow- from the control unit.

– Press open the latches of the fixture -arrows A- and pull the engine control unit forward -arrow B-.

– Release the catch of the second connector and un-plug the connector from the control unit.

Installation is carried out in the reverse order.

– Check current coding and code new control unit ⇒ 24-5 page 5.

– Adapt engine control unit to control unit for electronic immobiliser ⇒ Electrical System; Rep. Gr. 96.

– Activate cruise control system function in engine con-trol unit (on vehicles with CCS the lever for the CCS is located on the left below the steering wheel) ⇒ Chap. 24-6.

– Adapt the new control unit to the throttle valve control unit ⇒ 24-5 page 6.

– Adapt potentiometer for exhaust gas recirculation.

– Select function 04 „Basic setting“ and display group 070 when ignition is switched on.

Specification in display field 4:

ADP runs ADP O.K.

– Deactivate adaptation by pressing the button .


– Finally interrogate the fault memory of the new engine control unit and if necessary erase.

– Performing idling test ⇒ Chap. 24-4.

– Generate readiness code ⇒ Chapter 01-2.

S10-0111

S24-0337

A

A

B

System in basic setting 74 ->0.9V 3.8V 0.968V ADP. O.K.

Note



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Coding engine control unit

♦ A 5-digit code must always be displayed during the time the control unit identification is shown.

♦ If the code displayed does not match the vehicle, or if the control unit has been replaced, it is then neces-sary to code the control unit as follows.



Procedure


– Select function 07 „coding control unit“.

– Enter the relevant code number of the vehicle and

confirm with button .

The control unit identification number and the coding are shown on the display, e.g.:

If this display appears, an incorrect code number has been entered.

Note

Code control unit QEnter code number XXXXX (0-00127)

Q

Code number

for vehicles with

00001 Gearbox

00011 Gearbox and ABS

00021 Gearbox and airbag

00031 Gearbox, ABS and airbag

00041 Gearbox and air conditioning system

00051 Gearbox, air conditioning system and ABS

00061 Gearbox, air conditioning system and air-bag

00071 Gearbox, air conditioning system, ABS and airbag

00003 Automatic gearbox

00013 Automatic gearbox and ABS

00023 Automatic gearbox and airbag

00033 Automatic gearbox, ABS and airbag

00043 Automatic gearbox and air conditioning system

00053 Automatic gearbox, air conditioning system and ABS

00063 Automatic gearbox, air conditioning system and airbag

00073 Automatic gearbox, air conditioning sys-tem, ABS and airbag

036906034T MARELLI 4LV 2615 ->Coding 00031 WSCXXXXX

Function unknown or cannot ->be carried out at the moment



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♦ The engine control unit does not use the code entered and shown in the display until after the ignition has been switched off. Incorrect coding results in:

♦ Handling problems (jerky gear change, load change jolts etc.)

♦ Increase in fuel consumption

♦ Increase in pollution

♦ Storage of non-existent faults in fault memory

♦ non-execution of functions (lambda control, activated charcoal filter system actuation, etc.)

♦ On front-wheel-drive vehicles the Traction Control System does not operate (TCS warning light on)

♦ Reduction of the gearbox life

Adjusting the engine control unit to the throttle valve control unit

This adaptation teaches the engine control unit the vari-ous positions of the throttle valve with the ignition on and the engine stopped. These positions are stored in the en-gine control unit. The feedback of the throttle valve posi-tion is provided by the two angle sensors for the throttle valve drive.

Adaptation must be performed if:

♦ the power supply was interrupted

♦ the throttle valve control unit was removed and in-stalled

♦ the throttle valve control unit was replaced

♦ if another engine or another throttle valve control unit was installed




Test condition

• There must not be any fault present in the fault mem-ory ⇒ Chap. 01-1, Interrogating fault memory.


• Engine not running, ignition switched on.

• Accelerator pedal fully released.

• The throttle valve must be in idling speed position.

Note

Note



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• The coolant temperature must be 5...95 °C ⇒ display group 004, display field 3.

• When using the cruise control system, it must be cor-rectly set.

Procedure



In this state, the throttle valve is moved by a mechanical spring integrated in the throttle valve control unit, into an emergency running position. The values generated by the two angle senders in this emergency position are stored by the engine control unit.

Subsequently the throttle valve is opened at a given val-ue. If this value is reached, the throttle valve positioner is again switched dead. Now the mechanical spring must close the throttle valve within a given period in the previ-ously initialised emergency position (spring test).

The throttle valve is subsequently closed by the throttle valve positioner: the values sent by the angle sender to the throttle valve control unit are stored in the engine con-trol unit.

If during driving the engine control unit switches the throt-tle valve positioner dead, this is indicated by a fluctuating increased idling speed. The engine then has a very poor throttle response.

– Check the specified values for the throttle valve posi-tioner control unit in display fields 3 and 4.

Specification in display field 3: 12

Specification in display field 4:

ADP runs ADP O.K.


The adaptation was successfully performed.

To store the values:

– Switch ignition off for at least 30 seconds.

♦ If the basic setting is aborted by the control unit, this may be due to the following reasons:

♦ The throttle valve does not reach the mechanical idling limit due to dirt, e.g. carbon deposits or another mechanical fault.

♦ The battery voltage is too low.

System in basic setting 60 ->2% 95% 5 ADP. running

System in basic setting 60 ->2% 95% 12 ADP o.k.

Note



24-5 page 8

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♦ The throttle valve control unit or the cable connection is faulty, test ⇒ Chapter 24-2.

♦ If the basic setting is aborted, the fault is still in the fault memory. When the ignition is switched on again the basic setting is automatically performed again.



Testing auxiliary signalsEdition 03.01S00.5309.02.20

24-6 page 1

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24-6 Testing auxiliary signals

Testing the speed signal


♦ Vehicle system tester -V.A.G 1552 - with cable -V.A.G 1551/3, 3A, 3B oder 3C-

♦ Test box -V.A.G 1598/31-

♦ Diode test lamp e.g. -V.A.G 1527 B-

♦ Adapter cable set, e.g. -V.A.G 1594 A-

Test conditions

• Battery voltage must be at least 11.5 V.

• Speedometer o.k., testing ⇒ Electrical System; Rep. Gr. 90.

• Fuse 56 o.k.

Test sequence

♦ The vehicle must be driven in order to test the vehicle speed signal. The assistance of a second person is required.

♦ Pay attention to safety precautions for test drives ⇒ Chap. 24-1.

– Connect vehicle system tester -V.A.G 1552 -. Leave the engine on and select address word 01 „Engine electronics“ ⇒ Chap. 01-1.

– Select function 08 „Reading measured value block“ and display group number 005.

– Determine by means of a test drive whether the driv-ing speed is displayed in display field 3.

– Select function 06 „End output“ and switch off ignition.


– Connect the test box-V.A.G 1598/31- to the wiring loom on the engine control unit ⇒ Chap. 24-5. The engine control unit is not connected.

– Connect the multimeter for voltage measurement be-tween the bushes 4 (Term. 15) + 54 (speed signal) of the test box.

– Switch on the ignition.

– Raise the front left side of the vehicle.

– Turn the front left wheel by hand.

Diode test lamp must flash (very short signal).

If the diode test lamp does not flash:

Note

Reading measured value block 5 -> 1380 rpm 20 % 15 km/h Enrich-


Testing auxiliary signals Edition 03.01S00.5309.02.20

24-6 page 2

24

– Test the wiring to the speedometer and to the speed-ometer sender ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Locations

Testing signals from/to the air condition-ing system



Test conditions

• The air conditioning system must be switched off.

• There must not be any fault in the fault memory, inter-rogate fault memory ⇒ Chap. 01-1.

Test sequence



– Readout on display:

– Observe display field 2.

Specified value: 840/min

Specifications in display fields 3 and 4: „off“

– Switch on the air conditioning system.

– Observe display field 2.

Specified value: 870/min

Specifications in display fields 3 and 4: „on“




– Test the air conditioning system ⇒ Heating, Air Con-ditioning; Rep. Gr. 01.

– Check the CAN databus ⇒ 24-6 page 7.

Test brake light switch -F- and brake pedal switch -F47-



♦ Test box -V.A.G 1598/31-

Reading measured value block 50 -> 830/min 840/min off off



24-6 page 3

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♦ Handheld multimeter, e.g. -V.A.G 1526 A-


Test conditions

• Fuses Nos. 2 and 28 O.K.

Test sequence

– Connect vehicle system tester -V.A.G 1552 -. Switch the ignition on and select address word 01 „Engine Electronics“ ⇒ Chap. 01-1.


– Check the display value in display field 2.

Specified value: „x x 0 0“

– Operate brake pedal

Specified value: „x x 1 1“




– Remove the bottom part of the dash panel on driver side ⇒ Body Fitting Work; Rep. Gr. 70.

– Unplug the connector from the brake light/brake pedal switch.

– Connect the multimeter for resistance measurement between contact 1 and 4.



Specified value: max. 1.5 Ω






– Replace the brake light/brake pedal switch.


– Test the cable to the sender for open circuit and for short circuit to battery positive or earth ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Lo-cations.

Reading measured value block 66 -> 0 km/h 0000 0 km/h 0000

S24-0458

4 1



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Testing clutch pedal switch -F36-

Signal from clutch pedal switch -F36- is used for avoiding engine overrevving and load change jolts when the clutch is released.



♦ Test box -V.A.G 1598/31-



Test condition

• Fuse 28 must be o.k.

Test sequence



– Check the display value in display field 2.

Specified value: x0xx

– Operate clutch pedal.

Specified value: x1xx




– Remove the bottom part of the dash panel on driver side ⇒ Body Fitting Work; Rep. Gr. 70.

– Unplug the connector at the clutch pedal switch.



– Operate clutch pedal.



– Replace the clutch pedal switch -F36-.


– Test the cable to the sender for open circuit and for short circuit to battery positive or earth ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Lo-cations.

S01-0094

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S24-0458

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Activating and deactivating cruise con-trol system (CCS)



Test conditions

• There must not be any fault in the fault memory ⇒ Chap. 01-1, Interrogating fault memory.

Test sequence


Readout on display, e.g.:

If „MARELLI 4LV G“ is displayed, CCS is activated.

Readout on display, e.g.:

If „MARELLI 4LV“ is displayed, CCS is not activated.

– Press and select function 11 „Login procedure“.

Enter the code number by referring to table below and confirm entry with .


Conduct a test drive after activating the CCS.

Testing CCS

With the exception of an operating switch the CCS does not have any components of its own. All functions are performed by the engine control unit. The minimum vehi-cle speed for the CCS function is 30 km/h.



Test conditions

• Activate CCS ⇒ 24-6 page 5.

036906034F MARELLI 4LV G 2615 ->Coding 00031 WSC XXXXX

036906034F MARELLI 4LV 2615 ->Coding 00031 WSC XXXXX

Login procedure Enter code number XXXXX

Q

Code number Cruise control system (CCS)

11463 Cruise control system (CCS) is acti-vated

16167 Cruise control system (CCS) is deac-tivated



24-6 page 6

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Test sequence



– Read off the values in display fields 2 and 4.

Display field 2

Specified value:

1xxx - CCS activated

0xxx - CCS deactivated

Display field 4



– Test wiring to CCS switch for open circuit as well as short circuit to earth and to positive ⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Loca-tions.

Testing gear signal

Only for vehicles with autom. gearbox

The engine control unit receives from the gearbox control unit the information: Gear engaged (selector lever in 1/2/3/R/D) or no gear engaged (selector lever in P or N)



Test condition

• The selector lever of the automatic gearbox must be in position „P“ or „N“.

• Air conditioning switched off.


N23-0199BA

Test condition Display field 4

Switch -B- locked to „OFF“ 0000

Switch -B- to „OFF“ before operating point

00011)

Switch -B- to „ON“ 0011

Switch -B- to „RES“ 1011

Switch -A- pressed (switch -B- to „ON“) 0111

1) Not active at present.



24-6 page 7

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Test sequence



– Test the value in display field 4.

Specified value:

00000 (selector lever in P or N)

00010 (selector lever in 1/2/3/R/D)




– Check the data bus ⇒ 24-6 page 7.

Test data bus

Operation

The engine control unit communicates over a CAN data-bus with all the control units with databus capability.

The control units with databus capability are linked by two twisted databus cables (CAN_High and CAN_Low) and exchange information (messages). Both the engine con-trol unit and the other CAN data bus control units detect missing information on the data bus as faults.

Test condition

• A fault is detected by the CAN databus by self-diagno-sis.


♦ Test box -V.A.G 1598/31-



Test sequence

– Switch off the ignition.

– Release the connector of the engine control unit and unplug it.

– Connect test box -V.A.G 1598/31 - to engine control unit ⇒ Chap. 24-5. Wiring loom to control unit is not connected.

– Test the central terminating resistor in the engine con-trol unit.

– To to this, conduct a resistance measurement be-tween test box sockets 58 and 60.

Specified value: 60...72 Ω

Reading measured value block 56 -> 840 rpm 840 rpm 5 Nm 00000



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If the resistance value is not within the nominal value range:

– Replace the motronic control unit ⇒ Chap. 24-5.

If the resistance value is within the nominal value range:

– Test the CAN databus ⇒ Electrical System; Rep. Gr. 90.


Repairing ignition systemEdition 06.04S00.5309.04.20

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28-1 Repairing ignition system

General notes on the ignition system

♦ This section specially deals with the components in the ignition system. For other components of the injec-tion and ignition system ⇒ Rep. Gr.24.

♦ Switch off the ignition before disconnecting and con-necting the battery, as this may damage the 4AV con-trol unit.

♦ The engine control unit is equipped with a self-diagno-sis system.

♦ Components marked with an * are checked by self-di-agnosis ⇒ Chapter 01-1.

♦ A minimum voltage of 11.5 V is required for perfect functioning of the electrical components.

♦ Before repairs and for fault finding interrogate the fault memory ⇒ Chap. 01-1.

♦ Certain inspections may cause the control unit to de-tect and store a fault. It is therefore necessary to inter-rogate the fault memory after having completed all inspections and repairs, and if necessary erase ⇒ Chapter 01-1.

♦ If after fault finding, repair or inspection of compo-nents the engine starts briefly and then stops, it is pos-sible that the immobiliser blocks the 4AV control unit. The fault memory must then be interrogated and if necessary adapted to the engine control unit ⇒ Chapter 24-5.

Safety measures ⇒ 28-1 page 3.

Setting data, spark plugs ⇒ Inspection and Maintenance.

28 – Ignition System


Repairing ignition system Edition 06.04S00.5309.04.20

28-1 page 2

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Removing and installing parts of the ignition system for engines with the engine codes AUA, AUB

1 - Ignition lead with shielded plug and spark-

plug Resistor 4.8...7.2 kΩ

2 - Ignition transformer -N152- with identification for ignition

leads:A = Cylinder 1B = Cylinder 2C = Cylinder 3D = Cylinder 4 check ⇒ 28-1 page 6 Fitting location ⇒ Chapter

24-1

3 - Connector 4-pin for ignition transformer

-N152-

4 - 10 Nm5 - Connector

2-pin for knock sensor 1 -G61- Contacts of connector gold-

plated

6 - Knock sensor 1 -G61- *

check ⇒ 28-1 page 11 Fitting location ⇒ Chapter

24-1

7 - 20 Nm The tightening torque influ-

ences the knock sensor func-tion

8 - Connector 3-pin for hall sender -G40-


check ⇒ 28-1 page 4 Fitting location ⇒ Chapter 24-1


11 - Ignition lead guide12 - Spark-plug, 30 Nm

use of the spark plug wrench e.g. -3122 B- for removing and installing type and electrode gap ⇒ Inspection and Maintenance



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Removing and installing parts of the ignition system for engines with the engine codes BBZ, BBY, BKY

1 - Connector 4-pin

2 - Ignition coils with a power output stage -N70, N127, N291, N292- remove with extractor

-T 10094- check ⇒ 28-1 page 8

3 - Connector 2-pin for knock sensor 1 -G61- contacts gold-plated

4 - Knock sensor 1 -G61- *


24-1

5 - 20 Nm The tightening torque influ-

ences the knock sensor func-tion

6 - Connector 3-pin for hall sender -G40-



24-1


9 - 10 Nm10 - Spark-plug, 30 Nm

use of the spark plug wrench e.g. -3122 B- for removing and installing

type and electrode gap ⇒ Inspection and Maintenance

11 - Bracket Tighten at cylinder head cover to 5 Nm

Safety measures

Observe the following points to prevent injury to persons and/or damage to the injection and ignition system:

♦ Do not touch or remove ignition leads with the engine running or at start speed.

♦ Ignition must be switched off before disconnecting and re-connecting cables of the fuel injection and igni-tion system as well as of test equipment.




28-1 page 4

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♦ Always secure the test and measuring devices on the rear seat and also have a second person operate them there.


♦ If the engine must be operated at start speed without the engine starting:

Engines with the engine codes AUA, AUB


Engines with the engine codes BBY, BBZ, BKY

– Remove the connector and pull out all ignition coils with extractor -T 10094-.

For all vehicles


Testing hall sender


♦ Test box -V.A.G 1598/31-




Test condition


Test sequence




28-1 page 5

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– Disconnect the 3-pin plug connection from Hall sender -arrow-.

– Connect the multimeter for voltage measurement to contact 1 (positive) and 3 (earth) of the plug for the Hall sender.





– Connect test box -V.A.G 1598/31- to wiring loom of control unit ⇒ Chapter 24-5.





If no fault was found in the cables and the specified volt-age measured between contacts 1 + 3:

– Replace hall sender -G40-.



V


1 98

2 86

3 108



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Checking the ignition transformer (for engines with the engine codes AUA, AUB)


♦ Test box -V.A.G 1598/31-



♦ Diode test lamp e.g. -V.A.G 1527-


Test conditions


• The hall sender must be OK, test it ⇒ 28-1 page 4.

• The engine speed sender must be O.K., test it ⇒ Chapter 24-3.

Test sequence


Checking voltage supply

Test condition

• Fuse 52 must be o.k.

– Measure power supply between contacts 2 + 4 of the removed plug using the multimeter.





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– Check the cable between 4-pin plug contact 2 and the relay plate for interruption according to the Current Flow Diagram.


– Check the cable between 4-pin plug contact 4 and the earth for interruption according to the Current Flow Di-agram.


Test control


– Connect the diode test lamp to contacts 1 + 4 (ignition outlet 1) and contacts 3 + 4 (ignition outlet 2) of the re-moved plug.

– Actuate the starter and check the ignition signal on the engine control unit. The LED must flash.


If the LED flashes and there is a voltage existing between contact 2 and 4:

– Replace ignition transformer -N152- ⇒ item 2 in 28-1 page 2.

If the LED does not flash:

– Test wiring ⇒ 28-1 page 8.

WARNING!

During the following test do not touch neither the connecting parts of the ignition transformer nor the auxiliary cables.



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Checking wires






If no fault was detected in the wiring and if there is a volt-age detected between contact 2 and 4:


Testing secondary resistances

– Test secondary resistances on terminal 4 between cylinder 1 + cylinder 4 and cylinder 2 + cylinder 3.

Specified value: 4,0 ... 6.0 kΩ (at 20 °C)


– Replace ignition transformer -N152- ⇒ item 2 in 28-1 page 2.

Check ignition coils with power output stage (engines with engine codes BBY, BKY, BBZ)


♦ Test box -V.A.G 1598/31-



♦ Diode test lamp e.g. -V.A.G 1527 B-


Test sequence

Ignition coil and power output stage form a building unit.

Cylinder, which does not operate or misfire, determine as follows:

– Test combustion misfiring ⇒ 28-1 page 13.


1 102

3 103

Note



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If a combustion misfiring was detected:

– Proceed with test on cylinder determined as defective.

If no combustion misfiring was detected:

– Successively remove contacts of the injectors while engine is running and monitor engine run,

or

– Compare spark plugs of all cylinders and pay attention to contaminated (covered with soot) electrodes.

If a defective cylinder was determined:

– Replace the spark plug of the defective cylinder with the one of another cylinder.

If the fault on this spark plug still exists:

– Replace spark plug.

If the given cylinder is still defective:

– Replace the ignition coil of the defective cylinder with the one of another cylinder.

If the fault on this ignition coil still exists:

– Replace ignition coil.

If the given cylinder is still defective:

– Remove the 4-pin plug -1...4- from the ignition coils and check wiring ⇒ Current Flow Diagrams, Fault Finding and Fitting Locations.

Checking voltage supply

– Unplug the 4 pin plug connections from all ignition coils.

Test condition

• The fuses of the ignition system must be in proper or-der ⇒ Current Flow Diagrams, Fault Finding and Fit-ting Locations.

– Measure the voltage supply beween contacts 2 + 4 and 3 + 1 of the removed plug using the multimeter and the adapter cables from the measuring tool set.







28-1 page 10

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– Check the cable between 4-pin plug contact 3 and the relay plate for interruption according to the Current Flow Diagram.


– Check the cable between 4-pin plug contact 2 + earth and contact 1 + earth for interruption according to the Current Flow Diagram.


Test control


– Connect the diode test lamp V.A.G 1527 with adapter cables from V.A.G 1594 to contacts 1 + 4 of the re-moved plug.

– Actuate the starter and check the ignition signal on the engine control unit.

The LED must light up.


If the diode lights up and there is a voltage existing be-tween contacts 1 + 4:

– Replace ignition coil.

If the LED does not light up:

– Check wires.

WARNING!

Caution! During the following test do not touch neither the connecting parts of the ignition coils nor the auxiliary cables.



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Checking wires

– Connect test Box V.A.G. 1598/31 to wiring loom of the control unit. The engine control unit is not connected.





If no fault has been determined on the wiring and there is a voltage between contacts 2 + 3:


Testing knock sensor

♦ The perfect functioning of the knock sensor requires an exact tightening torque of 20 Nm.

♦ Only use gilded contacts to repair contacts in the plug connection of the sender.


♦ Test box -V.A.G 1598/31-




Plug contact 4 cylinder:

Test box bush -V.A.G 1598/31-

1 102

2 103

3 94

4 95

Note



28-1 page 12

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Test condition

• Faults on the knock sensor detected by self-diagnosis ⇒ Chapter 01-1, interrogate fault memory and erase.

Test sequence

– Disconnect the 2-pin plug from the knock sender -ar-row-.







– Slacken knock sensor and then tighten again to 20 Nm.

– Perform a test drive.

Comply with the safety instructions for a test drive ⇒ 28-1 page 3.



♦ After reaching the corresponding temperature, the fol-lowing operating conditions must be reached a number of times: Idling, part load, full load, overrun.


– Interrogate the fault memory on the control unit again.

If the fault still exists:

– Replace knock sensor -G61-.


1 106

2 99



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Test combustion misfiring



Test condition

• Driving

Test sequence



– Read off value in display block 4.

Specified value: „activated“.

– Check the number of combustion misfirings in indica-tor field 3.

Specified value: 0.




– Changeover in indicator group 015.


Specified value: „activated“.

– Check misfiring combustion in the indicator fields 1 to 3, cyl. 1...3.

Nominal values: 0.

– Changeover in indicator group 016.


Specified value: „activated“

– Check the number of combustion misfirings in indica-tor field 1, cyl. 4.

Specified value: 0.

If the nominal values in the display groups 015 and 016 are achieved:



– Eliminate fault ⇒ Chapter 01-3, Analysing display group 015 and 016.

Reading measured value block 14 ->840/min 17% 0 activated

Reading measured value block 15 ->0 0 0 activated

Reading measured value block 16 ->0 activated



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fuel injection aua,aub,bby,bbz,bky

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