6.0l w12 engine in the audi a8l - audi klub polska most powerful 12-cylinder engine available in...

6.0L W12 Engine in theAudi A8L

SELF-STUDY PROGRAMCOURSE NUMBER 921403

Audi of America, Inc.Service TrainingPrinted in U.S.A.Printed 11/2004Course Number 921403

©2004 Audi of America, Inc.

All rights reserved. All informationcontained in this manual is based on thelatest information available at the time ofprinting and is subject to the copyrightand other intellectual property rights ofAudi of America, Inc., its affiliatedcompanies and its licensors. All rights arereserved to make changes at any timewithout notice. No part of this documentmay be reproduced, stored in a retrievalsystem, or transmitted in any form or byany means, electronic, mechanical,photocopying, recording or otherwise,nor may these materials be modified orreposted to other sites without the priorexpressed written permission of thepublisher.

All requests for permission to copy andredistribute information should bereferred to Audi of America, Inc.

Always refer to existing electronic serviceinformation for information that maysupersede any information included inthis booklet.

Trademarks: All brand names and productnames used in this manual are tradenames, service marks, trademarks, orregistered trademarks; and are theproperty of their respective owners.

1

Contents

TTTTThe self-studyhe self-studyhe self-studyhe self-studyhe self-study pr pr pr pr progrogrogrogrogram is not intended aam is not intended aam is not intended aam is not intended aam is not intended as as as as as aWWWWWorkshop Manual. orkshop Manual. orkshop Manual. orkshop Manual. orkshop Manual. VVVVValues given aralues given aralues given aralues given aralues given are onlye onlye onlye onlye only intended t intended t intended t intended t intended tooooohelp ehelp ehelp ehelp ehelp explain the subject matterxplain the subject matterxplain the subject matterxplain the subject matterxplain the subject matter and r and r and r and r and relate telate telate telate telate to theo theo theo theo thesofsofsofsofsoftwartwartwartwartware version applice version applice version applice version applice version applicable at the time ofable at the time ofable at the time ofable at the time ofable at the time ofpublicpublicpublicpublicpublication.ation.ation.ation.ation.

The self-study program contains information on designfeatures and functions.

Always use the latest technical publications whenperforming maintenance and repair work.

AttentionNoteNew

Introduction ............................................................................................................... 2

Technical Data, Cross Section, Longitudinal Section, W Design

Cylinder Block ........................................................................................................... 7

Cylinder Block and Crankcase ......................................................................... 9

Crankshaft ................................................................................................................13

Pistons/Connecting Rods .................................................................................16

Engine Mounting ...................................................................................................17

Engine Lubrication ...............................................................................................18

Cooling System .....................................................................................................22Electronically Controlled Cooling System, Map-Controlled Engine Cooling Thermostat (F265)Control Loop

Cylinder Head .........................................................................................................31

Camshaft Drive ......................................................................................................32Sealing of Timing Mechanism, Valve Timing/Camshaft Timing Control, Internal EGR, Valve Tim-ing/Adjustment Range, Control and Monitoring of Camshaft Position, Camshaft Adjusters,Function of Camshaft Adjusters, Electro-Hydraulic Control, Adjustment in Retard Direction,Adjustment in Advance Direction, Adjustment in Controlled Position

Belt Drive/Auxiliaries...........................................................................................46

Water-Cooled Alternator ...................................................................................47

Induction System .................................................................................................49

Engine Sub-Systems ...........................................................................................51

Engine Management Concept .......................................................................54

Service .......................................................................................................................77

Introduction

2

The new top of the line models from theVolkswagen Group feature an innovativegeneration of W engines developed fromthe model used for the VR engine family.

To achieve this, mass producedcomponents have been integrated into acompletely new engine concept.

This process has yielded compact, multi-cylinder gasoline engines of a consistentlyhigh standard not previously achieved inpassenger car series production.

For example, the W12 6.0 L engine, featuredfor the first time in the Audi A8L, is currentlythe most powerful 12-cylinder engineavailable in this vehicle class, providing acombination of quality and optimumperformance.

SSP267 _205

Introduction

3

TTTTTececececechnichnichnichnichnical Dal Dal Dal Dal Dataataataataata

Engine Code Letters: BSB

Design: W Engine with a V Angle of 15° and a Bank Angle of 72°

Capacity: 366 cu. in. (5998cm3)

Maximum Power: 450 hp (335 kW) at6200 RPM

Maximum Torque: 428 lb-ft (580 Nm)at 4000-4700 RPM*

Bore: 3.31 in. (84.0mm)

Stroke: 3.55 in. (90.27mm)

Compression Ratio: 11:1

Weight: 540 lb. (245 kg)

Fuel: PremiumUnleaded

Firing Order: 1-12-5-8-3-10-6-7-2-11-4-9

Ignition Interval: 60° Crankshaft

Engine Management: Motronic ME 7.1.1

Emission Standard: BIN 9 Federal

LEV I California

Engine Oil: VW 50301 (OW 30)

Oil Change Quantity: Approximately13 qt. (12.5 L) withFilter

Idling Speed: 560 RPM

* More than 90 % of Maximum Torque is available at 1800 RPM.

Premium unleaded 91 AK1/95 RON isrecommended for maximumperformance. Using regularunleaded results in reduced power.

0

30

60

90

120

150

180

210

240

270

300

330

0

60

120

180

240

300

360

420

480

540

600

660

1000 2000 3000 4000 5000 6000 7000

Engine Speed [RPM]

Pow

er [k

W]

Torq

ue

[Nm

]

SSP267_008

Introduction

4

CrCrCrCrCross Sectionoss Sectionoss Sectionoss Sectionoss Section

Special FSpecial FSpecial FSpecial FSpecial Featureatureatureatureatures of the es of the es of the es of the es of the W12W12W12W12W12

— 12-Cylinder, W Design Gasoline Engine— Aluminum Engine Block and Cylinder

Heads— Oil Supply with Wet Sump Lubrication

— Twin Overhead Camshafts with FourValves Each per Cylinder

— Roller-Type Rocker Fingers ValveOperation

— Infinitely Variable Timing Control forInlet and Exhaust Camshafts

SSP267_001

Introduction

5

Longitudinal SectionLongitudinal SectionLongitudinal SectionLongitudinal SectionLongitudinal Section

— Four Catalytic Converters forEmission Control

— Eight Oxygen Sensors for MixtureFormation Control and Emission ControlMonitoring

SSP267_002

Introduction

6

W DesignW DesignW DesignW DesignW Design

The new generation of W engines wasdeveloped to achieve a more compactdesign in relation to the number ofcylinders.

The W engines incorporate design featuresof the VR engine generation.

Combining two VR6 engines using a bankangle of 72° and a joint crankshaft createsa “V” V12 engine or a W12 engine.

V-engines with a small V angle are alsocalled VR engines. They benefit from thedesign advantages of both the smoothrunning in-line engine, and the shortdesign of the V-engine.

With a length of 20.2 in. (513mm) and awidth of 28.0 in. (710mm), the W12 enginehas the same space saving dimensions asthe V8 5V engine.

SSP267_082

60 - 90°15°

15° 15° 72°

In-line engine V-engine VR-engine(V-engine withsmall V-angle)

VR-engine VR-engine W-engine

+ =

Cylinder Block

7

The cylinder block is cast from a hyper-eutectic aluminum silicon alloy (Alusil).

When this alloy solidifies, it produces puresilicon crystals and aluminum silicon mixedcrystals.

A special cylinder honing process exposesthe separated silicon crystals and theprocess creates wear resistant cylindercontact surfaces that eliminate the need foradditional liners.

The coolant reservoir, water pump housingand thermostat housing are integrated intothe vee of the cylinder banks and reducethe number of external coolant pipes.

MajorMajorMajorMajorMajor Advantages of this MonolithicAdvantages of this MonolithicAdvantages of this MonolithicAdvantages of this MonolithicAdvantages of this MonolithicSolid Solid Solid Solid Solid Aluminum BlocAluminum BlocAluminum BlocAluminum BlocAluminum Block:k:k:k:k:

— Optimum heat transfer from cylindersurface to heat-dissipating water jacket

— No thermal expansion problemscompared to material combinations(e.g. inserted grey cast iron liners)

— Same thermal expansion characteristicsallow minimal piston running clearanceover the entire temperature range andresults in smooth operation

— Considerable weight saving

Cylinder bank 1 Cylinder bank 2

Coolantcollector

Thermostat housing

Direction of travel

Water-pump housing

23

45

6

7 8

9 10

11 12

•

1

SSP267_029

Cylinder Block

8

The “fan” arrangement of the cylinder boreswith a V angle of 15°, and a bank angle of72°, creates a compact and rigid cylinderblock.

With a conventional layout, the very narrowV angle of 15° and the design of thecylinder block would affect the cylinderoverlap in BDC position.

As a result, the cylinders are offset withrespect to the axis of crankshaft rotation.The cylinder center axes do not coincidewith the crankshaft axis, but are offset tothe left or right.

This arrangement is known as cylinderoffset.

Together with an appropriate piston skirtdesign, the necessary clearance in BDCposition is achieved. (Refer to Section onPistons/Connecting Rods.)

The offset cylinder configuration requirescorresponding design modificationsaffecting both crankshaft group and valvetiming.

Cylinder bank 1Cylinder bank 2

15°

72°

15°

SSP267_034

Cylinder Block

9

-0.5

in. (1

2.5 m

m)

—

+—

+

Cylinder center axis/oddnumbered cylinders

Cylinder center axis/evennumbered cylinders

Line of crankshaft axis ofrotation parallel to cylindercenter axis

1 3 5

2 4 6

7 9 11

8 10 12

Bank 1

Bank 2

SSP267_098

The offset is as follows:

Odd-numbered cylinders - 0.5 in.12.5 mm (cyl. 1-3-5-7-9-11)

and

Even numbered cylinders + 0.5 in.+ 12.5 mm (cyl. 2-4-6-8-10-12)

SSP267_154

Cylinder Block and Crankcase

10

The crankcase is formed by the cylinderblock and the bearing support.

Cylinderblock

Bearing support

Top section ofsump

Sump

SSP267_137


11

The main bearing clearance is as constantas possible to satisfy noise levelrequirements over the entire operatingtemperature range. This is accomplished byusing a rigid bearing assembly.

The cast iron main bearing caps produce aform-fit in a rigid aluminum bearingsupport.

Each of the main bearings is only 0.59 in.(15mm) wide. Four permanently tightenedM8 bolts secure the main bearings.

The bearing support bolts to the cylinderblock, together with the top section of thesump and enhances the stability of theentire engine block.

A tapped crankshaft locating hole isprovided at the rear left of the bearingsupport.

By using of the appropriate locating pin, thecrankshaft is fixed in position at Number 1Cylinder TDC. The locating Pin is engagedin the crank web of Number 12 Cylinder.

Do not use the locating pin to providesupport, for example when looseningand tightening the central bolt.

Main bearing cap(cast iron)

Bearing support(aluminium)

Hole forlocating pin

Castwebs

SSP267_136


12

The method of attaching the engine blockto the transmission is unique.

The two upper transmission attachmentpoints protrude through the timing chaincover to provide a connection.

These connection pieces are fitted withradial seals.

Pulsation holes in the bearing blocksallow pressure equalization betweenthe cylinder chambers.

Cylinder bank 2

Radial seals

Cylinder bank 1

Timing chain cover

SSP267_107

SSP267_105

Crankshaft

13

The seven bearing crankshaft is forged andmade of heat-treated steel.

The creation of the uniform ignition intervalof 60° (standard for 12 cylinder engines),requires modifications to the crankshaft.

As is the case with V-engines, twoconnecting rods are mounted on eachcrank pin.

Due to the bank angle of 72°, the six crankpins are offset 12° relative to thecorresponding opposite cylinders. This is a“split pin” configuration.


15° 72°

15°

SSP267_034

SSP267_095 SSP267_089

Crankshaft

14

+/+ Center points of corresponding crank pins

21,833°

Zyl.7Zyl.1

Zyl.12Zyl.6

Zyl.5

Zyl.2

Zyl.8

Zyl.10

Zyl.4Zyl.9

Zyl.3Zyl.11

12°

120°

120°

120°

SSP267_081

SSP267_080

Crankshaft

15

On a conventional 12-cylinder engine, thecrank pins are mutually offset by 120°.

With the W12 engine, the cylinder offsetmeans that there is an interval of 21.833°between the two crank pins on each plane.

As a result, the crank pin travel (angle)differs along the circular path from TDC toBDC and from BDC to TDC.

The two facing rows of cylinders in onebank oppose those in the other bank.

This explains the need for both theunconventional crank pin offset and thedifferences in valve timing for the evennumbered and odd numbered cylinders.


Cylinder axisl - Conrod lengthr - Crank radiusy - Offset at BDC

SSP267_102

Pistons/Connecting Rods

16

The pistons are made of a eutecticaluminum silicon alloy and are identical forboth rows of cylinders in each bank.

The joint flat cylinder head surface of thetwo rows of cylinders in each bank resultsin an asymmetrical combustion chamber.The piston crown is angled to create asymmetrical combustion chamber.

The installation direction is guided by thepiston crown angle.

The piston skirt is a shorter, stepped designto allow it to move between the bearingblocks.

Since the pistons move in aluminumcylinders, they have an electroplated ironcoating (Ferrostan).

Oil spray jets cool the pistons and preventthermal overloading.

The connecting rod upper end is atrapezoidal shape to reduce oscillatingmasses and distribute the combustion forcemore evenly.

Because of the compact design of cylinderblock and crankshaft, the connecting rodsare only 0.51 in. (13mm) wide at the largeconnecting rod eye.

As a result, the contact surface betweenconnecting rod cap and connecting rod isvery small. The bolted joint is machinedand fitted with anti-fatigue bolts.

Oil grooves in the connecting rod capfacilitate the exit of oil from the connectingrod bearing.

Compensation for the specific load actingon the connecting rod bearing is providedby a sputter bearing shell for theconnecting rod and a three-materialbearing shell in the connecting rod cap.

Sputtering is the application of bearingmaterial using electrical energy.

Since the bearings have no lugs, a specialtool must be used for connecting rodassembly.

Oil grooves

SSP267_140SSP267_031

Engine Mounting

17

Maximum ride comfort is achieved with theaid of two electrically-actuated enginemounts with hydraulic damping.

The solenoid valves are actuated by theECMs as a function of engine and vehiclespeed.

The left and right Electro-Hydraulic EngineMounting Solenoid Valves (N145 and N144)are actuated by Engine Control Modules(ECUs) 1 and 2 (J623 and J624) respectively.

The switching point is approximately 1100RPM when the vehicle is stationary,compared to less than 850 RPM at a speedof more than 4.5 mph (7 km/h).

Engine Mount/Cylinder Bank 1 with theRight Electro-Hydraulic Engine MountSolenoid Valve (N145)

Engine Mount/Cylinder Bank 2 with LeftElectro-Hydraulic Engine Mount SolenoidValve (N144)

SSP267_124

Engine Lubrication

18

The W12 engine lubrication system in the2005 A8L is a wet sump system. Earlier W12engines used a dry sump system.

The oil pump is mounted in the sump and ischain driven by the crankshaft.

CrankshaftOil Pump Drive Chain

Oil Sump(upper section)

Chain Tensioner

Oil Pump

Oil sump(bottom section)

Oil Pick-up

SSP267_200

Engine Lubrication

19

The oil filter housing and oil cooler moduleare mounted on the side of the engine thatincludes the water-cooled alternatormodule.

Another major difference with the lubrication system comparedto the earlier W12 versions is that the main bearings receive oilfrom the top of the central oil gallery rather than from thebottom.

CamshaftsBank 1

Oil retentionvalve

Oil retentionvalve

Tointermediate

shaft

Oil return

CamshaftsBank 2

Centraloil gallery

Riser

Oil return

Mainbearings

Main oilgallery

Oil supplyfrom sump

Piston spray jetswith oil-pressurevalves

To chaintensioner

Return

Supply SSP267_109

Engine Lubrication

20

The oil retention valves are located in therisers leading to the cylinder heads.

The valves prevent oil flowing back into thesump from the cylinder heads when theengine is turned off. This helps ensure arapid build up of oil pressure in the cylinderheads when the engine is restarted.

Cylinder head bank

Camshaft adjuster

Timing case

Camshaft

In the cylinder heads, the flow of oil isdistributed to the camshaft adjusters.Restrictors supply oil to the longitudinalgalleries, which supply the camshaftbearings and hydraulic elements.

At high engine speeds, the cylinder headsreceive large amounts of oil that flows backinto the sump through the oil returndrillings. The restrictors ensure that onlythe necessary amount of oil is fed in, thusreducing the oil pump drive power.

Direction of travel

SSP267_073

Oil retentionvalves

SSP267_133

Engine Lubrication

21

An oil separator for each cylinder bank ismounted under the intake manifold. Theseparators remove oil particles from theblow-by gases.

Blow-by gases are channeled to the oilseparator first through coarse-particleseparators integrated in the cylinder headsand lines.

A large portion of the oil is separated at theinlet to the oil separator by baffle plates.Three cyclone fine-separators operating inparallel separate the existing ultra-fine oildroplets and channel the blow-by gasesthrough a pressure control valve into thecylinder bank intake manifolds.

The separated oil collects in the bottompart of the separator and returns directly tothe cylinder heads.

Cooling System

22

The cooling system of the W12 engine ismade up of the following components:

– Water Pump in Cylinder Block/CrankcaseDriven Mechanically by Poly V Belt

– Map-Controlled Electrically OperatedContinued Coolant Circulation Pump

– After-Run Coolant Pump (V51) as backup for Mechanical Water Pump and forContinued Coolant Circulation

– Electronically Controlled CoolingSystem (Map-Controlled CoolantThermostat)

– Dual electric cooling fans– Map-Controlled Continued Coolant

Circulation– Water-Cooled Alternator

1 – Auxiliary Radiator2 – Thermostat for Auxiliary Radiator3 – Alternator4 – Engine Oil Cooler5 – Bleeder Screw6 – Bleeder Screw7 – Right and Left Regulating Valves8 – ATF Cooler9 – Expansion Tank10 – Map Controlled Engine Cooling

Thermostat11 – Coolant Temperature Sensor12 – Oil Cooler13 – Thermostat14 – Coolant Pump15 – After-Run Coolant Pump16 – Radiator17 – Heat Exchanger18 – Heat Exchanger

12

3

4

5

6

17

18

14 1316

1511

10

12

9

8

7

Right and LeftRegulator ValveN176 and N175

SSP267_202

Cooling System

23

The water pump distributes the coolant toeach of the two cylinder banks. The flow ofcoolant is split before being routedlongitudinally through the cylinder bank onthe inlet and exhaust ends.

Guide vanes ensure an even flow around allcylinders.

From the back of the cylinder head, part ofthe coolant flow for each cylinder bank iswithdrawn for alternator cooling and for theoil cooler.

Most of the coolant flows throughcalibrated holes on the exhaust end into thecylinder heads and passes transverselythrough them towards the inlet end.

The remainder of the coolant flow is routedinto the cylinder head on the inlet end.

The inner vee of the cylinder block has acoolant collector into which the coolantfrom both cylinder heads flows.

From there, the coolant flows through thelarge cooling circuit to the radiator, orthrough the small cooling circuit directly tothe thermostat housing and back to thewater pump.

Two heat exchangers, the alternator and oilcooler are integrated into the small coolingcircuit. The joint return pipe provides aconstant return flow to the water pump.

Cooling System

24

To radiator

Coolant collector

Thermostathousing

Coolantcollector

Supply from return pipeThermostat F265

From radiator

SSP267_038

SSP267_143

Cooling System

25

The After Run Coolant Pump (V51) has twofunctions:

1. To provide back up for the mechanicallydriven coolant pump at low enginespeeds and to ensure adequate coolantcirculation.The After Run Coolant Pump (V51) isactuated by the Coolant Pump Relay(J496) by ECU 1 (J623). Self-Diagnosisdoes not detect a blockage of the AfterRun Coolant Pump (V51).Map control is used in the After-RunCoolant Pump (V51) as necessary. Theparameters used are engine speed andcoolant temperature supplied by theEngine Coolant Temperature Sensor(G62).

Switching levels:Cut in: <840 RPM and >226°F (108°C)Cut out: >3000 RPM or <223°F (106°C)

2. To circulate the coolant duringcontinued coolant circulation.

OtherOtherOtherOtherOther C C C C Cooling Cirooling Cirooling Cirooling Cirooling Circuit Ccuit Ccuit Ccuit Ccuit Componentsomponentsomponentsomponentsomponents

A Non-Return Valve 1 stops the return ofcoolant to the radiator when the After-RunCoolant Pump V51 is operating.

A Non-Return Valve 2 in the inlet to theheating system heat exchangers preventsthe flow of coolant through the heatingsystem heat exchangers during continuedcoolant circulation.

To understand the need for Non ReturnValve 2, it is helpful to imagine thefollowing situation with no Non ReturnValve 2 in the circuit:

If a warm engine is briefly turned off at highambient temperatures, e.g. for re-fuellingafter a long road trip, continued coolantcirculation starts to operate. The After-RunCoolant Pump (V51) distributes the coolantthrough the open thermostat and themechanical water pump into the enginecooling jacket.

The coolant then flows back to the radiatorfrom the coolant collector. The coolant alsopasses through the permanently openreturn pipe and heating system return tothe pump/valve unit of the air conditioner(compared to when the engine is running).

As the Left and Right Heat RegulationValves (N175 and N176) of the pump/valveunit open, the flow would pass through theheating system heat exchangers and causethem to heat up if there were no non returnvalve fitted (because the circuit tcircuit tcircuit tcircuit tcircuit to ro ro ro ro radiatadiatadiatadiatadiatorororororwwwwwould be closed ofould be closed ofould be closed ofould be closed ofould be closed off on heating systemf on heating systemf on heating systemf on heating systemf on heating systemsupply end)supply end)supply end)supply end)supply end).

The combination of hot heating systemheat exchangers next to a cold, dampevaporator would cause enormoushumidification of the air in the airconditioner unit. Restarting (blower startup), would result in excessive misting of the(cold) windshield, a situation whica situation whica situation whica situation whica situation which Nonh Nonh Nonh Nonh NonReturn Return Return Return Return VVVVValve 2 is designed talve 2 is designed talve 2 is designed talve 2 is designed talve 2 is designed to pro pro pro pro preventeventeventeventevent.

A Non Return Valve 2 is defective when anexcessively high vent outlet temperature ispresent during a re-start after a brief stop(as described above).

Cooling System

26

ElectrElectrElectrElectrElectroniconiconiconiconicallyallyallyallyally C C C C Controntrontrontrontrolled Colled Colled Colled Colled Cooling Systemooling Systemooling Systemooling Systemooling System

To enhance efficiency, the coolanttemperature of the W12 engine iscontrolled electronically based on a map.

The coolant temperature regulationfunction should be viewed as a system.

The specified coolant temperature isimplemented with the aid of the electricallyheated Engine Cooling Thermostat (F265)and the Electric Fans operating as afunction of engine speed.

A particular feature of the W12 engine isthat there is only one Engine CoolantTemperature Sensor (G62) for the controlloop.

Engine speed, engine load, ambientEngine speed, engine load, ambientEngine speed, engine load, ambientEngine speed, engine load, ambientEngine speed, engine load, ambienttempertempertempertempertemperaturaturaturaturatureeeee (obtained from Intake AirTemperature Sensor [G42] in air massmeter) and engine oil temper engine oil temper engine oil temper engine oil temper engine oil temperaturaturaturaturatureeeee (fromEngine Oil Temperature Sensor [G8]) formthe basis for calculating a specifspecifspecifspecifspecifiediediediediedcoolant tempercoolant tempercoolant tempercoolant tempercoolant temperaturaturaturaturatureeeee.

The specified coolant temperature is alsoinfluenced by the knock control function,with the specified temperature beingreduced if possible in the event of knockingcombustion.

The specified coolant temperature variesbetween 221°F (105°C) in the lower partthrottle range and 194°F (90°C) at highengine loads or vehicle speeds in excess of112 mph (180 km/h).

The specified coolant temperature formsthe reference input variable for closed loopcontrol of the Map-Controlled EngineCoolant Thermostat (F265) and open loopcontrol of the Coolant Fan Valve (N313).

Map-Controlled Engine CoolingThermostat F265

Return flow from -Heating system -Oil cooler and- Alternator

From coolantcollector

Coolant pump

From radiator

SSP267_038

Cooling System

27

Map-CMap-CMap-CMap-CMap-Controntrontrontrontrolled Engine Colled Engine Colled Engine Colled Engine Colled Engine CoolingoolingoolingoolingoolingTTTTThermostat (F265) Chermostat (F265) Chermostat (F265) Chermostat (F265) Chermostat (F265) Controntrontrontrontrol Loopol Loopol Loopol Loopol Loop

The Map-Controlled Engine CoolingThermostat (F265) is actuated on a pulsewidth modulated basis with a duty cycle of0% to 100%.

ECM 1 (J623) uses the actualactualactualactualactual and specifspecifspecifspecifspecifiediediediediedcoolant temperature to calculate the Map-Controlled Engine Cooling Thermostat(F265) duty cycle and actuate it accordingly.

When de-energized (duty cycle 0%), thecontrol characteristic of the CoolantTemperature Regulator is at 221°F (105°C) atthe thermostat.

Given maximum (duty cycle 100%) of theMap-Controlled Engine Cooling Thermostat(F265), the control characteristic can bereduced to 194°F (90°C).

During continued coolant circulation, theduty cycle is 100%. As a result, the Map-Controlled Engine Cooling Thermostat(F265) opens at an appropriately lowtemperature, thus ensuring coolantcirculation by the After-Run Coolant Pump(V51).

If the Map-Controlled Engine CoolingThermostat (F265) (Heating Element) fails, afault message is stored in the fault memoryof ECM 1 (J623).

Hydraulic fan

After-RunPump V51

Engine Coolant TemperatureSensor-G62

Engine Control Module 1-J623

Auxiliary Engine CoolantPump Relay J496

Map-Controlled Engine CoolingThermostat F265

Coolant FanValve N313Drive Circuit Cooling Fan

Temperature Sensor G382

Diagnosis

SSP267_144

Cooling System

28

Coolant hose

Radiator

O-ring

Radiator fan V7

Retaining Pin

O-ring

Radiator fan V177

Coolant hose

Rubberinsulator

Radiator cowl

Rubberinsulator

Notes

29

Cylinder Head

30

The two cylinder heads in the W12 engineare based on the new cylinder head of theVR6 engine. The cylinder heads are bankspecific to permit camshaft drive from oneside.

Main features:

— Cross flow cylinder head with fourvalves –two overhead camshafts forinlet and exhaust

— Valve operation by roller type rockerfingers

— Hydraulic valve lifters— Infinitely variable timing control for inlet

and exhaust camshaft

Exhaust port

Camshaft forinlet valves

Camshaft forexhaust valves

Inlet port

SSP267_092

SSP267_091

Cylinder Head

31

The cylinder heads used in the VR6 enginewere modified as follows for the W12engine:

— Additional oil return channels onexhaust end due to greater inclinationof cylinder banks resulting from V angleof 72°.

— Adaptation of cylinder head water jacketto cross flow cooling concept.

The particular arrangement of the valvespermits the use of an inlet and an exhaustcamshaft and therefore separate camshaftadjustment.

The VR principle results in different inletand exhaust port lengths in the cylinderhead. This is offset by way of appropriateintake and exhaust system design, thusensuring virtually identical charge cycles inall cylinders.

Needle-bearing mountedroller-type rocker finger

SSP267_090

Camshaft Drive

32

The timing mechanism is located on theengine output end.

Timing mechanism drive is provided by asimplex chain running from the duplexchain sprocket mounted on the crankshaft,to the central intermediate shaft.

From there, one simplex chain each runs tothe left and right cylinder head to drive theinlet and exhaust camshafts in each case.


Chain tensioner/cylinder bank 2 Guide blade

Chain tensioner/cylinder bank 1

Primary Chaintensioner

Simplex chainsprocket

Intermediate shaft

Guide blade

Guide blade

SSP267_022

Camshaft Drive

33

Three spring-loaded hydraulic chaintensioners and the chain guides ensure thecorrect chain tension and smooth chainoperation (no ratchet mechanism).

Oil spray jets in the chain tensioner runnersprovide the necessary chain lubrication andcooling.

Chain sprocket forcamshafts/cylinder

bank 2

Intermediate shaft

Locating pin Sprocket forsimplex chain

Chain sprocket forcamshafts/cylinder

bank 1

SSP267_020

Camshaft Drive

34

Sealing of Sealing of Sealing of Sealing of Sealing of TTTTTiming Meciming Meciming Meciming Meciming Mechanismhanismhanismhanismhanism

SIS sealing (as of start of production)

A new feature is the use of the SealInjection System (SIS) for sealing the uppertiming chain covers.

The upper timing chain cover to lower coversealing surface has a groove, into which thesealing fluid is injected under pressure afterthe timing chain cover is installed.

The sealant is injected into the groove witha lubricating nipple.

Breather holes are provided at both ends ofthe groove to allow the escape of the airdisplaced by the sealant. Sealant isinjected into the groove until it emergeswithout any bubbles at both breather holes.

For details, refer to the current WorkshopManual.

Sealing surfacewith groove

Breather hole

Lower timing chain cover sealingsurface

Breather hole

Lubricating nipple

Upper timing chain cover of cylinder bank 1(Bottom view)

SSP267_062

Camshaft Drive

35

Silicone liquid seal (new)

A modified method of sealing the timingchain covers is gradually being introduced.

Sealing is performed in the usual way byapplying the sealant to the componentsbefore assembly.

The production of the sealing surfaces withgroove and chamfer is a new feature.

Both the groove and the chamfer improveadhesion and extend the service life of theseal.

For details, refer to the current WorkshopManual.

Chamfer

Groove

Chamfer

SSP267_197

SSP267_198

Camshaft Drive

36

VVVVValve alve alve alve alve TTTTTiming/Ciming/Ciming/Ciming/Ciming/CamshafamshafamshafamshafamshaftttttTTTTTiming Ciming Ciming Ciming Ciming Controntrontrontrontrololololol

The infinitely variable timing control for theinlet and exhaust camshafts on the W12engine permits “internal exhaust gasrecirculation.” This is why exhaust gasrecirculation is described here.

Exhaust GaExhaust GaExhaust GaExhaust GaExhaust Gas Recirs Recirs Recirs Recirs Recirculation (EGR)culation (EGR)culation (EGR)culation (EGR)culation (EGR)

Ever more stringent demands are beingmade of internal combustion enginesregarding power, torque, fuel economy andexhaust emission standards.

High combustion temperatures andpressures create unwanted NOx formationfrom the nitrogen contained in the intakeair.

Recirculating the exhaust gases to thecombustion chamber lowers thecombustion temperature and pressure, andleads to reduced NOx formation.

A distinction is made between external andinternal EGR.

With external EGR, the exhaust gas isrouted through a piping system with EGRvalve back into the intake port, where it isdrawn in again.

Key:1 Control unit2 EGR valve3 EGR temperature specification4 EGR pulse valve5 λ-probe/primary CAT6 Primary CAT

External exhaust-gasrecirculation

SSP267_108

Camshaft Drive

37

Internal EGRInternal EGRInternal EGRInternal EGRInternal EGR

With the W12 engine, an internal EGRsystem is used to reduce the NOx level.

Internal EGR involves controlling theoptimum setting of the residual gascomponent in the cylinders with an inletand exhaust valve timing adjustment.

The volume of exhaust gas re-circulateddepends on the amount of valve overlap.

Valve overlap is the angular range in whichthe inlet valve is already open before theexhaust valve closes.

The advantages of internal EGR include arapid reaction time (short distances), highrecirculation rate which can be achieved,good formation of the exhaust, fresh gasmixture, and fewer components.

Internal exhaust-gasrecirculation SSP267_117

Camshaft Drive

38

The graphs below illustrate the valveopening/closing times (maps) for differentload statuses with a warm engine. There isno valve overlap at idle and in the near idlerange.

There is no significant occurrence of NOx inthis range, thus eliminating the need forEGR. The precisely controlled charge cycleproduces a particularly smooth runningengine.

An appropriate valve overlap is set in thepart throttle range as a function of load andengine speed. This is the operating statusin which the highest level of NOx is found.The EGR reduces the NOx level and also hasa positive effect on fuel consumption.

In the full throttle range, the camshafts areset for maximum cylinder charge in linewith engine speed.

Inlet openingExhaust closingValve overlap

0

5

10

15

20

-5

-10

-15

-20

-25

n [ 1 /min ]

1000 2000 3000 4000 5000 6000

50 % load/operating temperature

°CS

bef

ore

TDC

°CS

aft

er T

DC

*

n [ 1 /min ]

1000 2000 3000 4000 5000 6000 -30

-20

-10

-0

10

20

30

°CS

aft

er T

DC

°CS

bef

ore

TDC

90 % load/operating temperature

* max. possible adjustment range/exhaust camshaft

* max. possible adjustment range/inlet camshaft

*

SSP267_083

SSP267_084

Camshaft Drive

39

VVVVValve alve alve alve alve TTTTTiming/iming/iming/iming/iming/Adjustment RangeAdjustment RangeAdjustment RangeAdjustment RangeAdjustment Range

Infinitely variable adjustment of the inletand exhaust camshafts is provided on theW12 engine to achieve optimum matchingof valve timing to the wide range of engineoperating points.

– The range of inlet camshaft adjustmentis 52° crankshaft.

– The range of exhaust camshaftadjustment is 22° crankshaft.

Optimum adjustment of valve timing isensured for the operating statuses…

…rapid catalytic converter warm up

…warm up phase

…operating temperature

…by way of separate maps.

The maps are referenced to engine speed,engine load and engine temperature (referto Page 38).

VVVVValve alve alve alve alve TTTTTiming*iming*iming*iming*iming*

Odd Numbered Cylinder Bank(Cylinders 1 - 3 - 5 - 7 - 9 - 11)

Io Advance 27° Before TDCRetard 25° After TDC

Ic Advance 183° After TDCRetard 235° After TDC

Eo Advance 235° Before TDCRetard 213° Before TDC

Ec Advance 20° Before TDCRetard 2° After TDC

*with 1mm valve lift and 0mm valveclearance

VVVVValve alve alve alve alve TTTTTiming*iming*iming*iming*iming*

Even Numbered Cylinder Bank(Cylinders 2 -4 -6 -8 -10 -12)

Io Advance 27° Before TDCRetard 25° After TDC

Ic Advance 188° After TDCRetard 240° After TDC

Eo Advance 230° Before TDCRetard 208° Before TDC

Ec Advance 20° Before TDCRetard 2° After TDC

Io = Inlet Openslc = Inlet ClosesEo = Exhaust OpensEc = Exhaust Closes

Because of the offset crankshaftgroup, the valve timing (Ic and Eo)differs for the even and oddnumbered cylinder banks.

12

11

10

9

8

7

6

5

4

3

2

1

080 160 OT240 320 400 480 560 640

Val

ve li

ft [m

m]

Crankshaft adjustment [°CS]SSP267_173

Camshaft Drive

40

CCCCControntrontrontrontrol and Monitol and Monitol and Monitol and Monitol and Monitoring of Coring of Coring of Coring of Coring of Camshafamshafamshafamshafamshaft Pt Pt Pt Pt Positionositionositionositionosition

A position sensor is located at eachcamshaft for control and monitoring of thecamshaft adjusters.

For exact determination of the camshaftadjustment, the basic settings (retardposition) of the four camshafts are learnedby the control modules (adaptation).

During adaptation, the solenoid valves arede-energized. The camshafts are moved toretard position (basic setting) both by thesetting of the solenoid valves and thedirection of pull exerted by the chain.

The position of the camshaft positionsensor signals relative to the engine speedsensor reference mark (actual values), isstored as basic position and compared tothe specified values. This provides thebasic values for camshaft timing control.

A distinction is made between basic andfine adaptation.

Basic adaptation is always implementedafter the ECM is de-energized (no Terminal30) or erasing of DTCs.

After starting the engine, the camshaftsbriefly remain in the basic position until theexact position of the camshafts withrespect to the crankshaft has beenestablished.

If the camshafts are already in basicposition (valves de-energized) and thecoolant temperature is greater than 185°F(85°C), and assuming basic adaptation hasbeen implemented, fine adaptation isalways performed breifly several times (forapproximately one second) after startingthe engine.

Adaptation of the inlet camshafts takesplace at idle or in the near idle range.

Adaptation of the exhaust camshafts takesplace in the engine speed range between1200 and 2000 RPM and at low engine load.

The two ECMs implement independentadaptation of the camshaft positions. Thecamshaft timing control function isdisabled if adaptation is not performedsuccessfully.

Camshaft PositionSensor 4/cylinderbank 2 G382


Camshaft PositionSensor/cylinderbank 1 G40


SSP267_125

Camshaft Drive

41

CCCCCamshafamshafamshafamshafamshaft t t t t AdjustersAdjustersAdjustersAdjustersAdjusters

The mode of operation of the camshaftadjusters is based on a hydraulic vane-typerotary motor.

The illustration below shows the position ofthe camshafts with the engine idling atoperating temperature.

The inlet camshaft is in retard position,whereas the exhaust camshaft is inadvance position. When the engine is

started, the exhaust camshafts are initially“drawn” towards retard position due to thelow oil pressure and direction of chain pull.

When the solenoid valves are de-energized,the inlet and exhaust camshafts alsoassume the retard position.


AdvanceRetard

E

Advance

RetardRetard

Retard

E

Advance

Advance

II

EEEEE - Exhaust adjustment range 11° (22° crankshaft)

IIIII - Inlet adjustment range 26° (52° crankshaft)

SSP267_128

Camshaft Drive

42

Pressurechamber

A

B

A

B

Pressurechamber

FFFFFunction of Cunction of Cunction of Cunction of Cunction of Camshafamshafamshafamshafamshaft t t t t AdjustersAdjustersAdjustersAdjustersAdjusters

The camshaft adjuster consists of the five-vane rotor (connected to the camshaft), thestator (connected to the chain sprocket) andthe electro-hydraulic control unit.

The arrangement of the oil drillings in therotor creates a pressure chamber on eitherside of each vane (pressure chambersA and B).

When oil pressure is applied to pressurechamber A, the rotor turns clockwise (inrelation to the stator). In terms of thecamshaft, this represents the “retard”position.

When oil pressure is applied to pressurechamber B, the rotor turns counter-clockwise (in relation to the stator). Interms of the camshaft, this represents the“advance” position.

The term “stator” may seemmisleading. The stator is driven by thetiming chain which causes it to rotateand thus it is not actually “static” initself. It does however always maintainthe same angular position with respectto the crankshaft. The rotor turnsrelative to the crankshaft and thus tothe stator.

Appropriate pressure control in the twopressure chambers (A and B) makes itpossible to set any arbitrary positionbetween the two stops, thus providinginfinitely variable camshaft timing control.

SSP267_054

SSP267_053

Camshaft Drive

43

Timing case

Hydraulic control unit

ElectrElectrElectrElectrElectro-Hydro-Hydro-Hydro-Hydro-Hydraulic Caulic Caulic Caulic Caulic Controntrontrontrontrololololol

Pressurized oil is conveyed withoutrestrictions, to the control unit/solenoidvalves through two separate holes. Non-return valves in the solenoid valve inletsboost the system function at low oilpressure. Depending on how they areactuated, the solenoid valves route thepressurized oil to pressure chambers A andB of the rotary motors.

The control unit also acts as the housing forthe camshaft rotary bushes, forming thelink between solenoid valve and rotarymotor.

ECMs 1 and 2 (J623/J624) actuate CylinderBank 1 Valve 1 for Camshaft Adjustment(N205)/Valve 2 for EGR (N213), CamshaftAdjustment Valve 1 (N318) and CylinderBank 2 Solenoid Valve 2 for CamshaftAdjustment (N208)/Camshaft AdjustmentValve 1 (N318).

The solenoid valves are proportional valves.They are PWM actuated and convert thecontrol current into a switch positiondepending on the pulse width. The valvesare identical. The wiring harnessconnectors are different shapes and colorsto make them easier to service.

The position to which the solenoid valvesswitch when de energized is the same forboth the inlet and exhaust rotary motors.

The setting of the solenoid valves is defined(by spring force), so that the oil pressure isapplied to Pressure Chamber A. The inletand exhaust camshafts are therefore in theretard position.

If there is no or only marginal oil pressure,the camshafts are also set to the retardposition because of the chain pull.

SSP267_133

Camshaft Drive

44

Non-return valvePort (A)

Non-return valve Port (B)

Oil supply Oil drain

Adjustment in Retard DirAdjustment in Retard DirAdjustment in Retard DirAdjustment in Retard DirAdjustment in Retard Directionectionectionectionection

Adjustment in Adjustment in Adjustment in Adjustment in Adjustment in Advance DirAdvance DirAdvance DirAdvance DirAdvance DirectionectionectionectionectionSSP267_127

SSP267_126

Camshaft Drive

45

Non-return valve

Adjustment in CAdjustment in CAdjustment in CAdjustment in CAdjustment in Controntrontrontrontrolled Polled Polled Polled Polled Positionositionositionositionosition

The camshaft adjusters are equipped withan auxiliary coil spring attached to theadjuster housing. This spring helps to turnthe internal rotor of the adjuster in the"advance" direction.

SSP267_146

Belt Drive/Auxiliaries

46

Water pump

Idler wheel

Air-conditioningcompressor

Tandem oilpump

Tensioning roller

Crankshaft

Alternator

Belt Drive/Belt Drive/Belt Drive/Belt Drive/Belt Drive/AAAAAuxiliariesuxiliariesuxiliariesuxiliariesuxiliaries

Idler wheel

Water-Cooled Alternator

47

Alternators generate a high level of currenteven at low speeds. With air-cooledalternators, the cooling output is a functionof speed, which results in extreme heatingof the components during high poweroutput combined with low speed. Highambient temperatures add to this situation.

To alleviate this condition, a water-cooled190 alternator with a power output of2660W is used on the Audi A8L W12.

The water-cooled alternator has a waterjacket that surrounds the stator windingand the surface of the rectifier diodes andregulator mounting plate.

The alternator water jacket is incorporatedinto the engine cooling circuit and providescooling in all operating ranges, especiallyhigh power output at low speeds. The“open” design pulley provides an exchangeof cooling air for the claw-pole rotor. Sincethe air vortex of the claw-pole rotor isenough, a fan impeller is not necessary.

Permanent magnets between the rotorsegments enhance the magnetic fluxbetween the claw-pole rotor and statorwinding and increase efficiency. The polesof the permanent magnets have the samepolarization as the rotor segments.

The permanent magnets are relatively weakto minimize self-excitation and to allowregulation of the alternator voltage.

SSP268_097

Water-Cooled Alternator

48

Water jacket

Permanent magnets between the rotor segments enhance themagnetic flux (from the claws to the stator windingand vice versa), thus preventing stray flux between the individualpoles.

MorMorMorMorMore e e e e Advantages of Advantages of Advantages of Advantages of Advantages of WWWWWateraterateraterater-C-C-C-C-CooledooledooledooledooledAlternatAlternatAlternatAlternatAlternatorsorsorsorsors

— Quiet operation results from eliminatingthe fan impeller. There is noaerodynamic flow noise.

— Smooth running due to rigid, encloseddesign of alternator housing.

— Eliminating the fan impeller results in adecrease in drive power required andyields up to 5% more efficiency (as afunction of speed).

— Recovery of heat lost to engine coolingcircuit during warm-up phase.

— High performance level due to constantcooling over entire speed range.

— Reduced susceptibility to high ambienttemperatures.

SSP268_050

SSP268_048

Induction System

49

The intake system of the W12 features twoMass Airflow Sensors and two ThrottleBody Control Modules. Each sensor andthrottle body is fed fresh air from its own airbox and filter.

Throttle Body Control Module J544 Throttle Body Control Module J338

The manifold itself is a split designcomprised of an upper and lower half. Theupper portion must be removed beforeservicing the ignition coils or fuel injectorsis possible. The upper half can be furtherdisassembled into three separate pieces.

Separate crankcase ventilation boxes aremounted under the upper half of the intakemanifold.

Induction System

50

Intake Manifold(upper section)

Pressure Control Valve for CrankcaseBreather System (left bank)

Intake Manifold(lower section)

Always refer to the repair informationwhen removing and installing the intakemanifold.

Gaskets and seals must always bereplaced. Special bolt tighteningprocedures must also be followed.

Engine Sub-Systems

51

Advantages of metal substrate over ceramicsubstrate catalytic converters:

— The lower flow resistance results in alower exhaust backpressure andenhanced power yield.

— The catalytic converter responsetemperature is reached faster becauseof the lower heat capacity of the metalsubstrate and reduces unwantedemissions.

Mixture composition and emission controlare monitored by four independent controlloops using eight heated oxygen sensors.

Each primary catalytic converter is assigneda wide band oxygen sensor as upstreamprobe and a step change probe asdownstream sensor. Operation of the wideband oxygen sensor is described inSSP 247.


Exhaust bank 1Cylinders 1-3


To main catalyticconverters



SSP268_079

Engine Sub-Systems

52

Exhaust FlapsExhaust FlapsExhaust FlapsExhaust FlapsExhaust Flaps

The W12 engine has two exhaust flaps. As afunction of engine load, engine speed andvehicle speed, the ECM 1 (J623) switchesthe exhaust flap on the right side and ECM2 (J624) switches the exhaust flap on theleft side.

The exhaust flaps are closed at idle, in thelower part throttle range and enhancesilencer efficiency.

When parameters exceed defined values,the exhaust flaps open and reduce exhaustbackpressure.

The comfort level is maintained in low loadranges without increasing exhaustbackpressure in higher load ranges.

OperOperOperOperOperation/Cation/Cation/Cation/Cation/Controntrontrontrontrol of Exhaust Flapol of Exhaust Flapol of Exhaust Flapol of Exhaust Flapol of Exhaust Flap

Spring force keeps exhaust flaps open inde-energized and depressurized conditions.

This ensures the free discharge of exhaustgases if the system fails and preventsreduced performance and/or damage to thecomponents.

Actuation of Exhaust Flap Valve (N321) orExhaust Flap Valve 2 (N322) applies vacuumto the vacuum unit and closes the exhaustflap by overcoming the spring force.Switching conditions for opening ofexhaust flaps is as follows:

Vehicle Speed > 3 mph (5 km/h)Engine Load > 50%Engine Speed > 2500 RPM

Non-return valve

Flap open

Energized

De-energized

Non-return valve

Vacuum reservoir

Intakemanifold

J623

Flap closed

VacuumAtmospheric pressure

J623

Vacuum reservoir

Intakemanifold

SSP268_179

SSP268_180

Notes

53

Engine Management Concept

54

The Engine Management System for theW12 engine, Motronic ME7.1.1, is a twocontrol module concept.

Two control units are identical and each isassigned to one cylinder bank. The twocylinder banks are considered separateengines.

However, certain sub-functions arecommon to ECM 1 (J623) for Cylinder Bank 1and Engine Control Module 2 (ECM 2) (J624)for Cylinder Bank 2

Control unit/cylinder bank assignmentidentification is provided by pin encoding inthe wiring harness. To provide a cleardistinction, the wiring harness to eachcontrol unit is wrapped with differentcolored tape.

Pin encoding means that:

— Pin 49 of ECM 1 (J623) is connected toTerminal 15.

— Pin 49 of ECM 2 (J624) is connected toTerminal 31.

Because of the Twin Control Unit Concept,both control units must:

— have the same software version.— be matched to the Cruise Control

System (CCS).— be matched to the Immobilizer.— be viewed as separate entities for self-

diagnosis.— have the same encoding.

SSP268_129

BOSCH BOSCHBOSCH BOSCH

Engine control module 2 J624 Engine control module 1 J623


55

OnlyOnlyOnlyOnlyOnly ECM 1 (J623) per ECM 1 (J623) per ECM 1 (J623) per ECM 1 (J623) per ECM 1 (J623) perffffforms theorms theorms theorms theorms thefffffollowing functions.ollowing functions.ollowing functions.ollowing functions.ollowing functions.

— Determination of specified speed valuesfor idling speed control

— Coolant temperature regulation,continued coolant circulation, actuationof continued After-Run Coolant Pump(V51)

— Provision of CAN data for drive systemCAN

— Actuation of Fuel Pump Relay (J17) andMotronic ECM Power Supply Relay(J271)

— Control of exhaust flap

ECU 1 (J623) prECU 1 (J623) prECU 1 (J623) prECU 1 (J623) prECU 1 (J623) processes the focesses the focesses the focesses the focesses the followingollowingollowingollowingollowinginterinterinterinterinterfffffaces.aces.aces.aces.aces.

— Brake Light Switch F/Brake Pedal Switch(F47)

— Engine Coolant Temperature Sensor(G62)

— Cruise Control Switch (E45)— A/C High Pressure Signal from A/C

Pressure Switch (F129)— Terminal 50 Signal— Engine Speed SignalOnlyOnlyOnlyOnlyOnly ECM 2 J624 per ECM 2 J624 per ECM 2 J624 per ECM 2 J624 per ECM 2 J624 perffffforms theorms theorms theorms theorms thefffffollowing functions.ollowing functions.ollowing functions.ollowing functions.ollowing functions.

— Misfire Detection— Processing of Engine Oil Temperature

Sensor (G8) signal SSP268_148

K50

Engine control module 2 J624 Engine control module 1 J623

Terminal 31Terminal 15


56

System LayoutSystem LayoutSystem LayoutSystem LayoutSystem Layout

Heated oxygen sensor 2 -G39/-G108

Throttle position sensor-G79/-G185

Oxygen sensors -G130/-G131

Mass airflow sensor -G70Intake airtemperaturesensor -G42

Throttle Valve Control Module 1 -J338

Engine ControlModule 1 -J623

Cruise ControlSwitch -E45

Drive circuit coolingfan temperaturesensor -G382

Additional signals

Camshaftposition sensors-G40 (inlet)-G300 (exhaust)

Knock Sensors 1 and2 -G61/G66

Brake Light Switch -FBrake Pedal Switch -F47

Engine speedsensor -G28

Engine coolanttemperature sensors-G2/-G62

Pin 49 toTerminal 15

DiagnosticConnection

DriveSystem CAN

Throttle Valve ControlModule 2 -J544

Engine speed sensor -G28

Heated oxygen sensors -G285/-G286

Oxygen sensors -G287/-G288

Additionalsignals

Mass airflow sensor 2 -G246Intake Air Temperature Sensor 2 -G299

Engine OilTemperature

CamshaftPosition Sensors-G163 (inlet)-G301 (exhaust)

Engine controlmodule 2 -J624

Knock sensors 3 and4 -G198/-G199 Pin 49 to ground


57

Secondary air injectionpump relay 2 -J545 withsecondary air injectionpump motor 2 -V189

Throttle Valve ControlModule 1 -J338

Secondary-air injectionsolenoid valve -N112

Ignition coils with poweroutput stage -N70, 127, 291,292, 323, 324

Evaporative emissioncanister purge regulatorvalve -N80

Fuel injectors -N30, 31, 32, 33,83, 84

Map-controlledEngine CoolingThermostat -F265

Motronic EngineControl ModulePower SupplyRelay -J271

Additionalsignals

Right Electro-hydraulic enginemount solenoidvalve -N145

Exhaust flapvalve -N321

Valve 1 forCamshaftadjustment-N205 (inlet)-N318 (exhaust)

Additionalcoolant pumprelay -J496 withafter-run coolantpump -V51

Secondaryair injectionpump relay -J299 withsecondary airinjectionpump motor-V101

Coolant fanvalve -N313

Fuel pumprelay -J17with fuelpump -G6

Relay forradiatorfan after-run -J397

Throttle valve controlmodule 2 -J544

Ignition coils withpower output stages -N325, N326, N327,N328, N329, N330

Fuel Injectors -N85, 86, 299, 300,301, 302

Secondary airinjection solenoidvalve 2 -N320

Additionalsignals

Left electro-hydraulic enginemount solenoidvalve -N144

Evaporative emissioncanister purge regulatorvalve 2 -N333

Valve 2 for camshaftadjustment-N208 (inlet)-N319 (exhaust)


58

Sensors/Sensors/Sensors/Sensors/Sensors/ActuatActuatActuatActuatActuatorsorsorsorsors

BlocBlocBlocBlocBlock Diagrk Diagrk Diagrk Diagrk Diagram Motram Motram Motram Motram Motronic ME7.1.1onic ME7.1.1onic ME7.1.1onic ME7.1.1onic ME7.1.1

A Battery

E45 Cruise Control Switch

F Brake Light Switch

F47 Brake Pedal Switch

F265 Map-Controlled Engine Cooling Thermostat

G2 Coolant Temperature Sensor

G6 Fuel Pump

G8 Oil Temperature Sensor

G28 Engine Speed Sensor

G39 Heated Oxygen Sensor

G40 Camshaft Position Sensor

G42 Intake Air Temperature Sensor

G61 Knock Sensor 1

G62 Engine Coolant Temperature Sensor

G66 Knock Sensor 2

G70 Mass Air Flow Sensor

G79 Throttle Position Sensor

G108 Heated Oxygen Sensor 2

G130 Oxygen Sensor

G131 Oxygen Sensor 2

G163 Camshaft Position Sensor 2

G185 Sensor 2 for Accelerator Pedal Position

G186 Throttle Drive (Power Accelerator Actuation)

G187 Angle Sensor 1 for Throttle Drive (PowerAccelerator Actuation)

G188 Angle Sensor 2 for Throttle Drive (PowerAccelerator Actuation)

G198 Knock Sensor 3

G199 Knock Sensor 4

G246 Mass Airflow Sensor 2





G296 Throttle Drive 2

G297 Angle Sensor 1 on Throttle Valve Drive 2

G298 Angle Sensor 2 for Throttle Valve Drive 2

G299 Intake Air Temperature Sensor 2



G382 Drive Circuit Cooling Fan Temperature Sensor

J17 Fuel Pump Relay

J271 Motronic ECU Power Supply Relay

J299 Secondary Air Injection Pump Relay

J338 Throttle Valve Control Module

J397 Relay for Radiator Fan After Run

J496 Auxiliary Engine coolant Pump Relay

J544 Throttle Valve Control Module 2

J545 Secondary Air Injection Pump Relay 2

J623 ECM 1

J624 ECM 2

M9 Left Brake Light Bulb

M10 Right Brake Light Bulb

N30 Cylinder 1 Fuel Injector




N70 Ignition Coil 1 with Power Output Stage

N80 Evaporative Emission Canister PurgeRegulator Valve





N112 Secondary Air Injection Solenoid Valve

N127 Ignition Coil 2 with Power Output Stage

N144 Left Electro Hydraulic Engine Mount SolenoidValve

N145 Right Electro Hydraulic Engine MountSolenoid Valve

N205 Camshaft Adjustment Valve 1


N291 Ignition Coil 3 with Output Power Stage

N292 Ignition Coil 4 with Output Power Stage





N313 Coolant Fan Valve


5959595959

Engine Management CEngine Management CEngine Management CEngine Management CEngine Management Conceptonceptonceptonceptoncept

31

S S S SS S

F265

S S S

1515

X

1530

N318 N205 N112 N321

M

M

F47

M10

G40 G300G66 G61

J17

N145 N80

J299

V101

31

G6

N31 N32N33 N83N84

G70/G42

+-

mL

G131

J623

G28G62

C

N30

D

N313

G2

F

D

B

G108

-

B

49

QP

15

N127

N291

N292

N323

N324

λλPZ

NZ

M9

+ +

+

-

A

XC

+

G39

λ

G130

E

A

PZ

NZ

D C

N70

G186 G187

M

G188

+ -

J338

01 22a

0,2a

6060606060

Engine Management CEngine Management CEngine Management CEngine Management CEngine Management Conceptonceptonceptonceptoncept

31

3015

X

S

G382

S

G8

S S

E

G246/G299

C

mL

G163 G301

N144 N319 N320

M

N208

J545

V189

31

N86N299

N302N301N300

G296 G297

M

G298

N333

G198 G199

t°

M

J496

V51

31

J271

QP

N325

J544

J397

A

λλPZ

NZ

G288G79 G185

+ - + -

1 2 3N326

N327 N328

+ +

N85

+ -

D E

X

J624

N329

N330

BB

-+-

G285 G286

PZ

NZ

λ

G287

4

8 9

65 7

E

D C

49

C


61


N320 Secondary Air Injection Solenoid Valve 2

N321 Exhaust Flap 1 Valve

N323 Ignition Coil 5 with Final Power Output Stage





N328 Ignition Coil 10 with Final Power OutputStage



N333 Evaporative Emission Canister PurgeRegulator Valve

V51 After-Run Coolant Pump

V101 Secondary Air Injection Pump Motor

V189 Secondary Air Injection Pump Motor 2

Additional SignalsAdditional SignalsAdditional SignalsAdditional SignalsAdditional Signals

1 Terminal 50

2 To Relay for Radiator Fan After-Run (J397)

3 AC High Pressure Signal from A/CPressure

Switch (F129) (High Pressure Switch)

4 AC Requirement Signal (from A/C ControlHead [E87])

5 Compressor “ON/OFF” Signal

6 Crash Signal

7 Engine Speed Signal

8 CAN Low/Drive

9 CAN High/Drive

Power Supply fromFuel Pump Relay (J17)

A

C

B

X

E

D

Motronic ECM Power

Supply Relay (J271)

Connections withinBlock Diagram

CCCCColorolorolorolorolor C C C C Codeodeodeodeode

= Input Signal

= Output Signal

= Positive Supply

= Ground

= CAN Bus


62

Special FSpecial FSpecial FSpecial FSpecial Featureatureatureatureatures ofes ofes ofes ofes ofMotrMotrMotrMotrMotronic ME7.1.1onic ME7.1.1onic ME7.1.1onic ME7.1.1onic ME7.1.1

The Motronic ME7.1.1 is an advancedversion of the Motronic ME7.1 and hasthese features:

— Larger computer capacity because ofnew computer-bound sub-functions

— Extension of control unit activities afterturning off the ignition with the aid ofmain relay concept

— Infinitely variable adjustment of inletand exhaust camshafts

— Designed to suit new broad bandoxygen sensor upstream of catalyticconverter

— Designed for coolant temperatureregulation

— Enhanced evaluation of signals fromEngine Coolant Temperature Sensor(G62)

— Management of additional and newCAN messages

G62 EvaluationG62 EvaluationG62 EvaluationG62 EvaluationG62 Evaluation

Precision sensing of the coolanttemperature over a broad temperaturerange is very important.

Precise determination of the coolanttemperature in the lower operatingtemperature range is required for coldstarting and subsequent warm up.

Coolant temperature regulation demandsexact recognition of the coolanttemperature in the upper operatingtemperature range.

The characteristic curve of the EngineCoolant Temperature Sensor (G62) (NTCSender) is steep over the temperature rangeto be recorded -- approximately 86°F (30°C)to 248°F (120°C).

At the same time, the coefficient ofresistance ranges from approximately25,000 Ohms to approximately 115 Ohms.The change in resistance per Kohm variesconsiderably at low and high temperatures.

To achieve the required level of accuracy forboth temperature ranges, the ME7.1.1 has aseparate evaluation circuit for each.

Changing to the evaluation circuit for theupper temperature range takes place at acoolant temperature of approximately 122°F(50°C).

RN

TC [Ω

]•

ϑ [°C] •

SSP268_190

104

3

2

3

2

4

6

8

103

3

2

4

6

8

102

8

-30 -20 0 20 6040 80 100 120


63

Main RelayMain RelayMain RelayMain RelayMain Relay C C C C Conceptonceptonceptonceptoncept

In earlier versions of the W12, the FuelPump Relay (J17) provided the powersupply for the sensors and actuators.

Now this task is performed by the MotronicECM Power Supply Relay (J271) (MainRelay).

As with the Fuel Pump Relay (J17), ECM 1actuates the Motronic ECM Power SupplyRelay (J271). Due to the Motronic ECMPower Supply Relay (J271), the ECMs canstill execute certain functions after theengine ignition has been turned off.

The following sensors/actuators aresupplied with power by the MotronicCurrent Supply Relay (J271):

— ECM 1— ECM 2— Cylinder Bank 1 Ignition Coils— Cylinder Bank 2 Ignition Coils— Camshaft Adjustment Valves— Engine Mounting Solenoid Valves— Coolant Fan Valve (N313)— Auxiliary Engine Coolant Pump Relay

(J496) (Continued After-Run CoolantPump [V51])

— Relay for Radiator Fan After-Run (J397)(Coolant Fan [V7])

— Map-Controlled Engine CoolingThermostat (F265)

After turning off the ignition, the ignitioncoils are still actuated until the enginestops to ensure ignition of the fuel alreadyinjected. This means that no unburnedfuel/air mixture reaches the exhaust system,which reduces the level of exhaustemissions.

The camshaft adjustment valves alsoremain actuated until the engine stopswhen the ignition is turned off, to ensurethat the camshafts are kept in the properposition until the engine has stopped.

The Engine Mounting Solenoid Valvesprovide smooth engine shutoff.

The Solenoid Valve for the hydraulic fanprevents brief fan speed increase.

Since ECM 1 is responsible for control ofthe continued coolant circulation process, itactuates: Auxiliary Engine Coolant PumpRelay (J496), Relay for Radiator Fan After-Run (J397) and Map-Controlled EngineCooling Thermostat (F265).


64

Engine Speed Sensor G28Engine Speed Sensor G28Engine Speed Sensor G28Engine Speed Sensor G28Engine Speed Sensor G28

The Engine Speed Sensor G28, supplies themost important engine management inputsignal.

If the Engine Speed Sensor (G28) fails, theengine will not run.

The Engine Speed Sensor (G28) is directlyconnected to both ECMs. The sensor is aDifferential Hall Sensor with integratedpermanent magnet that scans ferro-magnetic sensor wheels.

If the sensor signal is missing, it isrecognized by the ECM self-diagnosisfunction.

— G40 Camshaft Position Sensor/CylinderBank 1




+ + + + +

J623 J624

31

G40 G300 G28 G163 G301

SSP268_159

SSP268_164


65

Engine speed sensor -G28

Evaluation electronics

Hall element 1

Permanent magnet

Hall element 2

Rotor (sender wheel)

Magnetic lines of force

SSP268_167

SSP268_168


66

Sensor DesignSensor DesignSensor DesignSensor DesignSensor Design

Signals are generated by two Hall elementsarranged behind the sensor wheel.

A permanent magnet is located above thetwo Hall elements and integrated into thesensor. The magnetic field acts on the Hallelements. The integrated evaluationelectronics, also called Hall IntegratedCircuit (IC) evaluate the Hall voltages of thetwo Hall elements and generate the sensoroutput signal.

Hall elements react to changes in themagnetic field. IC refers to an integratedsemi-conductor circuit.

The sensor wheel is a rotor and influencesboth the field strength of the permanentmagnet and the Hall voltages of the twoHall elements. If the ferrous metal rotor islocated directly under the Hall elements, theferrous metal intensifies the magnetic fieldin the area of the Hall elements. The Hallvoltage of the two Hall elements increaseswith increasing magnetic field strength.

Since the two Hall elements are arrangedbehind one another, the Hall voltage levelsat the Hall elements change during thetransition from rotor to gap (or vice versa).

The difference between and the magnitudeof the Hall voltages are used for evaluationand generation of the output signal.

UHE1

UHE2

Hal

l vol

tag

e U

HE

NS

UHE1UHE2

Hal

l vol

tag

e U

HEN

S

HE1 HE2

Outputsignal

UHE1UHE2

Hal

l vol

tag

e U

HE

NS

IC means “Integrated Circuit” and refersto an integrated semi-conductor circuit.

SSP268_194

SSP268_195

SSP268_196


67

CCCCCamshafamshafamshafamshafamshaft Pt Pt Pt Pt Position Sensorsosition Sensorsosition Sensorsosition Sensorsosition Sensors

In addition to defining the camshaftposition with respect to the position of thecrankshaft, a camshaft position sensor isrequired for each inlet and exhaustcamshaft adjustment.

Sensor signals are required for thefollowing functions.

————— Engine Speed Sensor (G28) andEngine Speed Sensor (G28) andEngine Speed Sensor (G28) andEngine Speed Sensor (G28) andEngine Speed Sensor (G28) andCamshafCamshafCamshafCamshafCamshaft Pt Pt Pt Pt Position Sensorosition Sensorosition Sensorosition Sensorosition Sensor (G40) (G40) (G40) (G40) (G40)

— Synchronization of Bank 1 (withCylinder 1/Cylinder 6) for knock controland sequential injection; G300 isresponsible for synchronization if G40fails.

————— Engine Speed Sensor (G28) andEngine Speed Sensor (G28) andEngine Speed Sensor (G28) andEngine Speed Sensor (G28) andEngine Speed Sensor (G28) andCamshafCamshafCamshafCamshafCamshaft Pt Pt Pt Pt Position Sensorosition Sensorosition Sensorosition Sensorosition Sensor (G163) (G163) (G163) (G163) (G163)

— Synchronization of Bank 2 (withCylinder 12/Cylinder 7) for knock controland sequential injection; G301 isresponsible for synchronization if G163fails.

Bank 2 synchronization is offset by 60° withrespect to Bank 1. The pin encodingensures that allowance is made for this inthe software.

————— Engine Speed Sensor (G28) andEngine Speed Sensor (G28) andEngine Speed Sensor (G28) andEngine Speed Sensor (G28) andEngine Speed Sensor (G28) andCamshafCamshafCamshafCamshafCamshaft Pt Pt Pt Pt Position Sensors (G40/300)osition Sensors (G40/300)osition Sensors (G40/300)osition Sensors (G40/300)osition Sensors (G40/300)

— Control and monitoring of camshaftadjustment for Cylinder Bank 1

————— G28 and G163/301G28 and G163/301G28 and G163/301G28 and G163/301G28 and G163/301— Control and monitoring of camshaft

adjustment for Cylinder Bank 2— There is no camshaft timing control

function if one of the camshaft positionsensors is defective.

— If both the camshaft position sensorson one bank fail, engine starting isenabled by the engine run-out detectionfunction.

Adaptation of Sensor Signals (G40/G300/G163 and G301) provides more accuratedetermination of the camshaft basicpositions.


Camshaft positionsensor 4 -G301

Camshaftposition sensor 2-G163

Camshaft positionsensor 1 -G40

Camshaft posi-tion sensor 3 -G300SSP268_147


68

Sensor DesignSensor DesignSensor DesignSensor DesignSensor DesignThe camshaft position sensor is also calleda “Differential Hall Sensor” that uses a two-track rapid start sensor wheel made offerrous metal.

The sensor wheel has two broad and twonarrow rotors/gaps.

This design has different rotor widths andenables the signal profiles of the CamshaftPosition Sensors (G40/G163) and the EngineSpeed Sensor (G28) to be used for fasterdetermination of camshaft adjustment withrespect to the crankshaft.

Track 1

Track 2

Camshaft positionsensor

Permanentmagnet

Hall element 1

Hall element 2

SSP268_149


69

Another feature of the sensor wheel designis that two “tracks” are in adjacent, mutuallyinverted arrangement.

The two-track system ensures more precisegeneration of the sensor signal.

The signals are generated by two HallHallHallHallHallelements HE1elements HE1elements HE1elements HE1elements HE1 and HE2HE2HE2HE2HE2 that are situatednext to the sensor wheel. One track isassigned to each of the Hall elements.

A permanent magnet is situated above thetwo Hall elements and integrated into thesensor, the field of which acts on the Hallelements. The IC electronics evaluate theHall voltages of the two Hall elements andgenerate the sensor output signal.

Hall elements react to changes in themagnetic field. The two-track sensor wheelinfluences the strength of the permanentmagnet.

When the ferrous metal rotor of track 1 islocated directly under HE1, there is a gapunder HE2. The ferrous metal intensifiesthe magnetic field in the area of HE1 andthe Hall voltage of HE1 increases withrespect to HE2.

The difference between HE1 and HE2 andthe magnitude of the two Hall voltages isused for evaluation and generation of theoutput signal.

Hall element 1

Hall element 2

Track 2

Track 1

Permanent magnet

SN

SSP268_151

SSP268_150


70

The signal profiles of the camshaft positionsensors are identical for Cylinder Banks 1and 2 intake and exhaust camshafts (samedistance from software reference mark).

Basic synchronization of the first ignitionTDC (ITDC) of Cylinder Bank 1 (Cylinder 1) is78° after the software reference mark.

Because of the special features of theengine mechanical and managementsystems, basic synchronization of the firstignition TDC (ITDC) of Cylinder Bank 2(Cylinder 12) is 138° after the softwarereference mark.

Allowance is made for this in the controlunit and the pin encoding specifies it.

78°

138°

40°

40°

140°

40°

92°

660°720° 0° 60° 120° 180°

6°

240°

114°

Cam

shaf

t Pos

ition

Sen

sors

-G30

0/-G

301

Cam

shaf

t Pos

ition

Sen

sors

-G40

/-G

163

Cam

shaf

t Pos

ition

Sen

sors

-G28

SSP268_085


71

140°

140°

40°

300° 360° 420° 480° 540° 600°

The engine speed sensor is a Hallsensor. The software reference mark isthe second trailing edge after the gap(60-2 system).

The camshafts are in “retard” position if theCamshaft Adjustment Valves are de-energized when the engine is running. Ifthere is no or not enough oil pressure, thecamshafts are set to retard positionbecause of the chain pull.


72

Engine Oil Engine Oil Engine Oil Engine Oil Engine Oil TTTTTemperemperemperemperemperaturaturaturaturatureeeeeSensor (G8)Sensor (G8)Sensor (G8)Sensor (G8)Sensor (G8)

The signal of the Engine Oil TemperatureSensor (G8) is evaluated by ECM 2 (J624)and transmitted by the CAN Bus to ECM 1(J623).

It is used for calculating the specifiedcoolant temperature and the continuedcoolant circulation time.

To prevent overheating of the engine,mandatory change from 4th to 5th gear isimplemented when the engine oiltemperature is more than 266°F (135°C).

The decrease in engine speed counteracts afurther increase in engine oil temperature.

The mandatory change described abovealso takes place when the coolanttemperature is more than 248°F (120°C).

Oiltank

Engine oiltemperaturesensor -G8

Engine control module 2 -J624

Transmission control module -J217

CAN

Engine control module 1 -J623

SSP268_145

Notes

73


74

CAN DCAN DCAN DCAN DCAN Data Excata Excata Excata Excata Exchangehangehangehangehange

The Twin Control Module Concept hasresulted in the addition of new CANmessages, over which the two ECMsexchange data. ECM 1 transmitsinformation to ECM 2 by “Master/SlaveMessages.”

Master/Slave Messages provide ECM 1 withdata from ECM 2.

Although these messages arAlthough these messages arAlthough these messages arAlthough these messages arAlthough these messages are tre tre tre tre transmittedansmittedansmittedansmittedansmittedbybybybyby the gener the gener the gener the gener the general drive system CAN, theyal drive system CAN, theyal drive system CAN, theyal drive system CAN, theyal drive system CAN, they ar ar ar ar areeeeeonlyonlyonlyonlyonly used f used f used f used f used fororororor the e the e the e the e the excxcxcxcxchange of datahange of datahange of datahange of datahange of databetween the twbetween the twbetween the twbetween the twbetween the two ECMs.o ECMs.o ECMs.o ECMs.o ECMs.

ECM 2 can only transmit by way ofSlave/Master Messages. AlthoughECM 2 can transmit data to ECM 1 andthe Dash Panel Insert (Immobilizer), itis only designed to receive data.

Data transmitted by the ECMs

Data received and evaluated by theECMs

1 These data are additionally transmittedby way of Master Slave Messages

2 These data are only transmitted by way ofMaster/Slave Messages

3 These data are only transmitted by way ofSlave/Master Messages

ECM 1ECM 1ECM 1ECM 1ECM 1

(Master Control Module)

— Intake Air Temperature— Brake Light Switch1

— Brake Pedal Switch— Throttle Valve Angle— Electronic Throttle Warning Lamp/

Info— Driver Input— Torque— Fault Status1

— Accelerator Pedal Position1

— CCS Switch Positions— CCS Specified Speed— Altitude Information— Compressor Switch-Off— Compressor ON/OFF (Feedback from

Bi-Directional Interface)— Fuel Consumption— Coolant Temperature1

— Idling Speed Recognition— Engine Shutoff Position2

— Engine Speed— ACTUAL Engine Torques— Emergency Running Programs

(Self-Diagnosis Information)— G8 Oil Temperature Warning— VMax Limit Active2

— Immobilizer— Crash Signal2

ECM 2ECM 2ECM 2ECM 2ECM 2

(Slave Control Module)

— EPC fault Lamp Request3

— OBD Fault Lamp Request3

— Misfiring Detection3

— Fault Status3

— Engine Oil Temperature (From G8)3

— Immobilizer3


75

TTTTTrrrrransmission Cansmission Cansmission Cansmission Cansmission Controntrontrontrontrol Moduleol Moduleol Moduleol Moduleol Module

— Idle Regulation Adaptation Release— Compressor Switch-Off— Specified Idling Speed— Current Gear/Target Gear— Specified Engine Torque— Emergency Running Programs (Self-

Diagnosis Information)— Gearshift Active/Not Active— Selector Lever Position— Torque Converter Clutch Status

ESPESPESPESPESP/////ABS CABS CABS CABS CABS Controntrontrontrontrol Moduleol Moduleol Moduleol Moduleol Module

— Intervention Torque— Brake Pedal Status— ESP Intervention— Overrun Torque Limiting Function

Request— Overrun Torque Limiting Function

Intervention Torque

DDDDDaaaaash Psh Psh Psh Psh Panel Inseranel Inseranel Inseranel Inseranel Inserttttt

— Self-Diagnosis Information— Vehicle Speed— Coolant Temperature— Immobilizer (from both ECUs)

Steering Steering Steering Steering Steering Angle SensorAngle SensorAngle SensorAngle SensorAngle Sensor

— Steering Wheel Angle is used foridling speed pilot control and enginetorque calculation based on powersteering power requirements.

Dri

ve s

yste

m C

AN

Hig

h

Dri

ve s

yste

m C

AN

Lo

w


76

Additional Signals/InterAdditional Signals/InterAdditional Signals/InterAdditional Signals/InterAdditional Signals/Interfffffacesacesacesacesaces

In addition to CAN BUS data exchange, the following signals are sent by separateinterfaces.

Pin 42 Terminal 50 ECM* 1 OnlyPin 67 Crash Signal ECM 1 and ECM 2Pin 41 A/C Compressor Signal ON/OFF ECM 1 and ECM 2Pin 40 A/C Requirement Signal ECM 1 and ECM 2Pin 54 A/C High-Pressure Switch Signal ECM 1 OnlyPin 37 Engine Speed Signal ECM 1 OnlyPin 49 Pin Encoding of Control Units

+ to Pin 49 = ECU 1- Pin 49 = ECU 2

Pin 43 K-Wire/Diagnosis ECM 1 and ECM 2Pin XX only interfaces Cruise

ECM 1 Control System

* ECM = Engine Control Module

TTTTTerminal 50 Signalerminal 50 Signalerminal 50 Signalerminal 50 Signalerminal 50 Signal

The Engine Run-Out Detection Function canrecognize “reversing” in the course of theengine shutoff process. Because reversingof the engine is ruled out on starting, theTerminal 50 information (starter operated) isused for checking the plausibility of andevaluating the reversing detection function.

AirAirAirAirAir-C-C-C-C-Conditioneronditioneronditioneronditioneronditioner C C C C Compromprompromprompressoressoressoressoressor ON/OFF ON/OFF ON/OFF ON/OFF ON/OFFSignalSignalSignalSignalSignal

The compressor on signal is also used as asource of information for calculating thespeed of the electric fan.

AirAirAirAirAir-C-C-C-C-Conditioneronditioneronditioneronditioneronditioner High-P High-P High-P High-P High-Prrrrressuressuressuressuressure Switce Switce Switce Switce SwitchhhhhSignalSignalSignalSignalSignal

The signal from the A/C Pressure Switch(F129) (High Pressure) provides informationfor actuating the radiator cooling fans.

When the High Pressure Switch is closed(approximately 16 bar), maximum electricfan speed is set.

CrCrCrCrCraaaaash Signalsh Signalsh Signalsh Signalsh Signal

Although ECM 1 switches the fuel pump,the crash signal is also transmitted to ECM2. In addition to powering the Fuel Pump,the Fuel Pump Relay is also responsible forsupplying voltage to other actuators of bothECMs (refer to block diagram).

The crash signal in ECM 2 suppressesunwanted entries in the fault memory suchas those caused by deactivation of the fuelpump.

To avoid unnecessary expense, nomodifications have been made to thewiring harness (wiring to Pin 67 interfacestill exists).

Always check the wiringdiagrams for the latest pinassignments.

Service

77

Notes on MaintenanceNotes on MaintenanceNotes on MaintenanceNotes on MaintenanceNotes on Maintenance

Because of the Twin Control ModuleConcept, there are several factors toremember when using diagnostic testersand the self-diagnosis function

Regarding self-diagnosis, the two controlmodules should be viewed as separateentities (this does not apply to misfiredetection).

The self-diagnosis functions areimplemented in the control module towhich the components are connected (withthe exception of combustion missingdetection).

Separate address words are required forentry into self-diagnosis function:

Address word 0101010101 ECM 1 (J623)Cylinder Bank 1(Exhaust Banks 1 and 2)

Address word 1111111111 ECM 2 (J624)Cylinder Bank 2(Exhaust Banks 3 and 4)

If a fault has been stored in ECM 2, the fault“Please read out fault memory of ECM 2” isstored in ECM 1. This fault message canonly be erased when there is no fault entrystored in ECM 2.

Both control modules must:

— have the same software version— be matched to the Cruise Control

System (CCS)— be matched to the Immobilizer— be viewed as separate entities for self-

diagnosis— have the same encoding

The readiness code must be set, read outand reset separately for each controlmodule (e.g. by starting “short trip” testsequence with scan tool). Raising the faultmemory automatically sets the readinesscode in the appropriate control module.

The misfire detection function is onlyactivated in ECM 2 (J624), which is thusresponsible for both cylinder banks.

MisfMisfMisfMisfMisfiririririre detection afe detection afe detection afe detection afe detection affffffecting Cylinderecting Cylinderecting Cylinderecting Cylinderecting CylinderBank 1 cBank 1 cBank 1 cBank 1 cBank 1 can onlyan onlyan onlyan onlyan only be r be r be r be r be read out in ECM 2.ead out in ECM 2.ead out in ECM 2.ead out in ECM 2.ead out in ECM 2.

Service

78

WWWWWorkshop Eqorkshop Eqorkshop Eqorkshop Eqorkshop Equipment/Specialuipment/Specialuipment/Specialuipment/Specialuipment/SpecialTTTTToolsoolsoolsoolsools

These are the new items of workshopequipment and special tools designed forthe W12 engine.

VVVVVAS 6100 AS 6100 AS 6100 AS 6100 AS 6100 WWWWWorkshop Crorkshop Crorkshop Crorkshop Crorkshop CraneaneaneaneaneWith a load bearing capacity of 2650 lb.(1200 kg), the workshop crane VAS 6100 canhandle the new larger volume engines.

VAS 6101 Extension (load bearing capacity660 lb. or 300 kg) is available as an option.

VVVVVAS 6095 Engine and GearboAS 6095 Engine and GearboAS 6095 Engine and GearboAS 6095 Engine and GearboAS 6095 Engine and GearboxxxxxAssembly MountAssembly MountAssembly MountAssembly MountAssembly MountIn addition to a load bearing capacity of1320 lb. (600 kg), the Engine and GearboxAssembly Mount offers several newfeatures.

Unit mounting with universally adjustableclamps and locating pins provides easyaccess to the back of the engine.

The height of the unit can be adjusted byapproximately 7.9 in. (200 mm).

The tilt mechanism enables the unit to bemoved into any angular position required.

The mechanism is self-locking so that thereis no need for separate fixing.

Integrated storage facilities and sliding driptray for collecting fluids is included.

Compatible with existing engine andgearbox supports.

Unit Unit Unit Unit Unit AssemblyAssemblyAssemblyAssemblyAssembly TTTTTrrrrrolleyolleyolleyolleyolleyThis special tool is a unit assembly trolleyfor all engine and gearbox preassemblywork.

The worktable is in two sections to facilitateseparation and joining of the engine andthe gearbox.

Locatingpins

SSP268_186

SSP268_184

SSP268_182

Service

79

VVVVVAS 6131 ScissorAS 6131 ScissorAS 6131 ScissorAS 6131 ScissorAS 6131 Scissor Lif Lif Lif Lif Lift t t t t TTTTTableableableableable

Used for removing engine and transmissionassemblies from vehicles.

SSP268_181

SSP268_185

SSP268_187

Clamps

VAG 1342/16 Oil pressuretest pipe section

VAG 1342/15 Oilpressure test adapter

Service

80

Knowledge Assessment

iii

An on-line Knowledge Assessment (exam) is available for this SSP.

The Knowledge Assessment may or may not be required for Certification.

You can find this Knowledge Assessment at:

www.accessaudi.com

From the accessaudi.com homepage:

Click on the “ACADEMY” Tab –

Click on the “Academy Site” Link –

Click on the ”CRC Certification” Link –

For assistance, please call:

Audi Academy

Learning Management Center Headquarters

1-877-AUDI-LMC (283-4562)

(8:00 a.m. to 8:00 p.m. EST)

Knowledge Assessment

Audi of America, Inc.3800 Hamlin Road

Auburn Hills, MI 48326

6.0l w12 engine in the audi a8l - audi klub polska most powerful 12-cylinder engine available in...

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