The 6.0 l W12 engine in the Audi A8 - Part 2 Self-study ... - Volkspage

ContentsEngine, MechanicsPageBelt drive/ancillaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Water-cooled alternator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Hydraulic/electric fan control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Hydraulic fan circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Power steering circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Hydraulic fan control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Temperature sensor for radiator fan drive circuit -G382 . . . . . . . . . . . . . . . . . 9Electric fan control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Continued coolant circulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Engine sub-systemsInduction system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Exhaust system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Exhaust flap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Crankcase breather system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18System layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Secondary-air system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20System layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Vacuum system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23System layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Exhaust-gas recirculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Fuel tank breather system - activated charcoal filter (ACF) . . . . . . . . . . . . . . . . . . 25Engine managementEngine management concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26System layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Sensors/actuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30Special features of Motronic ME7.1.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Engine speed sender -G28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Sensor design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36Camshaft position senders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37Sensor design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38Oil temperature sender -G8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42Detection of combustion missing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42CAN data exchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44Additional signals/interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46ServiceNotes on maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Workshop equipment/special tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502The self-study programme contains information on designfeatures and functions.The self-study programme is not intended as a WorkshopManual. Values given are only intended to help explain thesubject matter and relate to the software version applicable atthe time of SSP compilation.Use should always be made of the latest technical publicationswhen performing maintenance and repair work.NewAttentionNote

Engine, MechanicsBelt drive/ancillariesWater pumpIdler wheelsAir-conditionerAlternatorCrankshaftTensioning rollerTandem oilpumpSSP268_0473

Engine, MechanicsWater-cooled alternatorTo satisfy the power supply requirements ofthe Audi A8 W12, use is made of a watercooled190 A alternator with a power outputof 2660 W.Alternators generate a high level of currenteven at low speeds. High componenttemperatures occur in this operating rangedue to the low speeds in relation to poweroutput.With air-cooled alternators, the coolingoutput is a function of speed, which results inextreme heating of the components in theevent of high power output in combinationwith low speed. High ambient temperaturesaggravate this situation.With water-cooled alternators, cooling isprovided by a water jacket surrounding thestator winding and the surface of themounting plate for rectifier diodes andregulator.The "open" design with respect to the pulleyprovides an exchange of cooling air for theclaw-pole rotor. The air vortex of the clawpolerotor is sufficient to achieve this.There is thus no need for a fan impeller.Permanent magnets between the rotorsegments enhance the magnetic fluxbetween claw-pole rotor and stator windingand serve to increase efficiency.For this purpose, the poles of the permanentmagnets have the same polarisation as therotor segments.The permanent magnets are relatively weakso as to minimise self-excitation and topermit regulation of the alternator voltage.The water jacket of the alternator isincorporated into the engine cooling circuit(refer to SSP 267, Page 34 onwards).This serves to guarantee constantly efficientcooling in all operating ranges, which is ofparticular significance in the previouslycritical operating range, namely high poweroutput at low speeds.4SSP268_097

SSP268_048Permanent magnets between the rotor segments enhancethe magnetic flux (from the claws to the stator windingand vice versa), thus preventing stray flux between theindividual poles.Water jacketFurther advantages of water-cooledalternators:– Quiet operation due to the absence of a fanimpeller (no aerodynamic flow noise)– Smooth running thanks to rigid, encloseddesign of alternator housing– Decrease in drive power required due toabsence of fan impeller yields up to 5 %greater efficiency (as a function of speed)– Recovery of heat lost to engine coolingcircuit during warm-up phase– High performance level thanks to constantcooling over entire speed range– Insusceptibility to high ambienttemperaturesSSP268_0505

Engine, MechanicsHydraulic/electric fancontrolHeat from the engine cooling system isdissipated by way of a hydraulic fan system incombination with a 300 W electric fan.Advantages of hydraulic fan system:– High overall system performance– High efficiency even at lowengine speeds– No drain on vehicle electrical system– Compact system allowing great flexibilityof fitting location– Infinite output control to suit requirementsOperationThe hydraulic fan is controlled as a functionof speed.The speed of the hydraulic fan basicallydepends on the quantity of fluid flowingthrough the hydraulic motor.In turn, the quantity of fluid is governed bythe pump volume (pump speed) and thetemperature of the hydraulic fluid.The radiator fan valve -N313 (actuated byengine control unit 1 -J623) regulates the flowof fluid to the hydraulic motor and providesinfinitely variable control of the fan speed.The hydraulic fan system was adopted fromthe V8 TDI engine and adapted to match thespecific features of the W12 engine (refer toSSP 226, Page 24 onwards).A new addition is the temperature sensor forthe radiator fan drive circuit -G382 (refer toPage 9).Hydraulic fan circuit:DistributorSuction hose/hydraulic motorcircuitTandem pumpReturn flow fromhydraulic motorSupply/hydraulic motor6Hydraulic motor

Steering boxFluid reservoirDirection of travelReturn flow fromhydraulic motorTemperature sensor -G382Return flow fromfluid coolerSupply/steering boxSupply/hydraulic motorReturn/hydraulic motorDistributorFluidcoolerSuction hose/steering box circuitHydraulicmotorReturn flowfrom steeringboxTandem pumpRadiator fanvalve -N313Suction hose/hydraulic motorcircuitSSP268_077Power steering circuit:Return flowfrom oil coolerFluid reservoirFluid coolerDistributorReturn flow fromsteering boxSuction hose/steering box circuitSteering boxTandem pumpSupply/steering box7

Engine, MechanicsHydraulic fan controlOn the basis of coolant temperature (-G62),ambient temperature (-G42) and vehicle speed,engine control unit 1 -J623 calculates aspecified fan speed as a function of thespecified coolant temperature.Further parameters for specified fan speed:– Air conditioner/compressor "ON"– Status of air-conditioner pressure switch-F129 (for further details, refer to Page 46)The fan speed is directly proportional to thevolume (speed) of the hydraulic pump, thetemperature of the hydraulic fluid and theswitching status of the radiator fan valve-N313.The radiator fan valve -N313 is actuated on apulse-width modulated basis with a dutycycle (TVH) of between 0 and 100 %.Valve -N313 is open when deenergised. In thisstatus, the hydraulic fan attains its maximumspeed of 2800 rpm.The fluid flow is then restricted by thepressure control valve in the pump.For technical reasons the hydraulic fan isnever completely shut down. Even when nocooling is required, it is actuated at aminimum speed of approx. 400 rpm.The current value for actuation of the radiatorfan valve -N313 is calculated from the pumpspeed (derived from engine speed), thespecified fan speed and the hydraulic fluidtemperature (from -G382).Pressure port/steering boxSuction port/steering boxPump section/power steeringPump section/hydraulic fan systemSuction port/hydraulic motorPump driveSSP268_028Pressure port/hydraulic motorRadiator fan valve -N313The hydraulic pump is of tandem design,supplying fluid pressure to the powersteering and hydraulic fan.8

Temperature sensor for radiator fan drivecircuit -G382The temperature sensor -G382 detects thetemperature of the hydraulic fluid, which is ofcrucial importance to the viscosity of thefluid.The viscosity influences the speed and thusthe performance of the hydraulic fan.For reasons of noise, the fan speed shouldnot exceed approx. 2100 rpm. This speed limitis referred to in the following as "comfortspeed".If the coolant temperature exceeds roughly115 °C, the hydraulic fan operates atmaximum speed regardless of the associatednoise level.In view of pump losses, the following rulesapply given a constant pump speed:– High hydraulic fluid temperatureLower fan speed– Low hydraulic fluid temperatureHigher fan speedPrevious control method(V8 TDI engine without -G382)The temperature of the hydraulic fluid is oneof the fan speed parameters. With regard tothe comfort speed, this was derived to datefrom the ambient temperature.With allowance for production tolerances,this method of determining the temperatureof the hydraulic fluid requires anappropriately large safety margin withrespect to the acoustically acceptablecomfort speed limit.Optimum use can therefore not be made ofthe comfort speed range, with the fan havingto run more frequently at maximum speed.New control method(with -G382)Sensing of the hydraulic fluid temperature(-G382) adds a further crucially importantparameter which considerably improveshydraulic fan control, thus permitting moreprecise regulation and consequently betterutilisation of the comfort speed range.More efficient use is made of the availablepotential up to the comfort speed limit.As a result, the fan does not have to beoperated as often at maximum speed with itsassociated high noise level.Temperature sensorfor radiator fandrive circuit -G382The internal gear of the hydraulic motorsimultaneously acts as fan drive gearand is driven by the regulated fluid flow.Trochoid internal gear ofhydraulic motorSSP268_0279

Engine, MechanicsElectric fan controlThe 300 W electric fan (radiator fan -V7)– Provides back-up for the hydraulic fansystem when the engine is running(irrespective of engine speed)– Ensures the necessary heat dissipationduring continued coolant circulationThe twin series resistor permits three speedsettings.Fan run-on (fan speed 1) is activated by enginecontrol unit 1 -J623 on the basis of thecontinued coolant circulation map andswitched by the radiator fan run-on relay -J397.Fan speed 2 is switched by the radiator fanthermoswitch -F18 or the air-conditioneroperating and display unit -E87.Fan speed 3 (max.) is switched either by the airconditionerpressure switch -F129 or, as of acoolant temperature of approx. 115 °C, by thecombi processor in the dash panel insert-J218. The input signal for this is supplied bythe coolant temperature sender -G2.Continued coolantcirculationContinued coolant circulation is regulated byengine control unit 1 -J623 in line with a map.Both the activation condition and thecontinued coolant circulation time aredetermined from the following parameters onthe basis of an arithmetic model:– Coolant temperature (from coolanttemperature sender -G62)– Engine oil temperature (from oiltemperature sender -G8)– Ambient temperature (from intake-airtemperature sender -G42)The activation condition and continued coolantcirculation period are constantly calculatedfrom the time of starting the engine.For continued coolant circulation, the pump-V51 and radiator fan -V7 are actuated inparallel.The maximum continued coolant circulationtime is limited to 10 minutes.The map-controlled engine cooling thermostat-F265 is fully actuated during continuedcoolant circulation.Examples of activation condition as a functionof ambient and coolant temperature:Vehicles for countries requiring anextremely high cooling output are fittedwith radiator fan 2 -V177.– Ambient temperature 10 °CCoolant temperature 110 °C– Ambient temperature -10 °CCoolant temperature 115 °C– Ambient temperature 40 °CCoolant temperature 102 °C10

3015XJ2713015XSSSJ397 J101 J135F129P311 234 5 6V7F18Mt°N3931SSP268_116F18F129J101J135J271J397N39SV7Radiator fan thermoswitchAir-conditioner pressure switchRadiator fan 2nd speed relayRadiator fan 3rd speed relayMotronic current supply relayRadiator fan run-on relayRadiator fan series resistorFusesRadiator fan1234From engine control unit 1 -J623From air-conditioner operating anddisplay unit -E87From combi processor in dash panelinsert -J218To engine control unit 1 -J6235To air-conditioner operating anddisplay unit -E876From air-conditioner operating anddisplay unit -E8711

Engine sub-systemsInduction systemThe induction system consists of a multipieceintake manifold.Infeed of activated charcoal filterand oil tank breather fumesThrottle valveAir-mass meter 2 -G246 withintake-air temperature sender 2 -G299Air cleaner box, bank 2, withsecondary-air pump motor -V101, bank 1To combination valvefor secondary-air systembank 112

Pressurelimiting valvesTo intakemanifoldSSP268_123Suction jet pumpBrake servo connectionAir-mass meter -G70 with intake-airtemperature sender -G42To combination valve forsecondary-air systembank 2SSP268_110Air cleaner box, bank 1, withsecondary-air pump motor 2 -V189, bank 213

Engine sub-systemsExhaust systemPrimary catalyticconverterCylinders 1-3Primary catalyticconverterCylinders 10-12G39G108PrimarycatalyticconverterCylinders 4-6Double-D pipeG285G286G288G130G131Decoupling elements(do not kink by morethan 10° to avoiddamage)Primary catalyticconverterCylinders 7-9G287LengthcompensationflangeMain catalyticconvertersTo offset production tolerances, the flangeconnections between the two primarycatalytic converters of exhaust banks 1 and 3and the intermediate pipe are provided witha length compensation flange.For manufacturing reasons, the clamp-typeflange connection at the primary catalyticconverter (exhaust bank 1/3) is additionallywelded after assembly in series production.The primary catalytic converters are thuspaired with the intermediate pipe.Consequently, replacement of the primarycatalytic converters (exhaust bank 2/4) orintermediate pipe also involves replacing theassociated primary catalytic converter(exhaust bank 1/3).Upstreamof CATG39G108G285G286Lambda probesDownstreamof CATG130G131G287G28814

The exhaust gas flow from three cylinders iscollected in an exhaust manifold with air gapinsulation, thus resulting in a total of four socalledexhaust banks (see illustration onPage 16).Each exhaust bank is assigned an underbonnet3-way primary catalytic converter(metal-substrate catalytic converter).After passing through the primary catalyticconverters, the exhaust gas flow of eachexhaust bank is routed separately (in fourchannels) to the two decoupling elements.The four-channel design of the exhaustsystem until just upstream of the maincatalytic converters (long separate exhaustflow routing) provides a vastly improvedtorque profile in the lower engine speedrange.This long exhaust gas flow separation isachieved by means of an intermediate pipe(fleece-insulated) with two D-section"inliners".The further conversion of the exhaust gasestakes place in the 3-way main catalyticconverter (metal-substrate catalyticconverter) assigned to each cylinder bank.An X-shaped pipe section causes the twoexhaust gas flows to merge before enteringthe centre silencer. The subsequent jointrouting in the centre and rear silencersproduces the typical 12-cylinder exhaustnoise.The right tailpipe is fitted with anelectronically actuated exhaust flap.X-shaped pipe sectionRear silencerCentre silencerExhaust flapSSP268_113Dual-flow tailpipewith noise optimisation15

Engine sub-systemsAdvantages of metal-substrate over ceramicsubstratecatalytic converters:– The lower flow resistance results in a lowerexhaust back pressure (enhanced poweryield).– The catalytic converter responsetemperature is attained more quickly onaccount of the lower heat capacity of themetal substrate (reduced pollutantemissions).Mixture composition and emission controlare monitored by way of four independentcontrol loops using eight heated Lambdaprobes.Each primary catalytic converter is assigned awide-band Lambda probe as upstream probeand a step-change probe as downstreamprobe. Operation of the wide-band Lambdaprobe is described in SSP 247 on Page 21onwards.Cylinder bank 2 Cylinder bank 1Exhaust bank 3Cylinders 7-9Exhaust bank 1Cylinders 1-3Exhaust bank 4Cylinders 10-12Exhaust bank 2Cylinders 4-6SSP268_079To main catalytic converters16

Exhaust flapThe exhaust flap is switched by enginecontrol unit 1 -J623 as a function of engineload, engine speed and vehicle speed.The exhaust flap is closed at idle and in thelower part-throttle range, thus enhancingsilencer efficiency.When the above parameters exceed certaindefined values, the exhaust flap is opened toreduce exhaust back pressure.This enables the comfort level to bemaintained in low load ranges without thedetrimental effect of increasing exhaustback pressure in higher load ranges.Operation/control of exhaust flapIn deenergised and depressurised condition,the exhaust flap is kept open by way of springforce.This ensures the unimpeded discharge ofexhaust gases in the event of system faults andprevents a reduction of performance and/orcomponent damage.Actuation of the valve -N321 causes vacuum tobe applied to the vacuum unit, thus closing theexhaust flap by overcoming the spring force.Switching conditions for opening of exhaustflap:Vehicle speed > 5 km/hEngine load > 50 %Engine speed > 2500 rpmNon-return valveIntakemanifoldVacuum reservoirJ623Flap openSSP268_179EnergisedDeenergisedNon-return valveIntakemanifoldVacuum reservoirJ623Flap closedSSP268_180Atmospheric pressureVacuum17

Engine sub-systemsCrankcase breather systemSystem layoutPressure limiting valvesCylinder bank 2Cylinder bank 1Fresh airImpacterDipstickImpacter/returnOil tankCrankcase breatherSSP268_06418

To intakemanifoldSSP268_123ImpacterBreather pipeBreather pipe topressure limitingvalvesCylinder headbreatherOil return to oiltankSSP268_007The breather fumes, consisting of blow-bygases and oil vapours, from the cylinderheads and central crankcase are collected inthe oil tank, from where they are routed viapressure limiting valves into the intakemanifold.An oil separator extracts the oil particles fromthe fumes so as to ensure that the gasesentering the intake system contain as little oilas possible even at high air flow rates.The pressure limiting valves restrict thevacuum in the engine. If the vacuum in theengine exceeds a certain value, thediaphragm is pulled (overcoming the springforce) onto the connection to seal it.This prevents excessive vacuum damagingthe axial oil seals.19

Engine sub-systemsSecondary-air systemSystem layoutCombination valve forsecondary-air systembank 2Secondary-air pumpmotor 2 -V189Secondary-air inletvalve 2 -N320Secondary-air pumprelay 2 -J545EnergisedDeenergisedVacuum reservoir20

Combination valve forsecondary-air systembank 1Secondary-air inletvalve -N112Secondary-air pumpmotor -V101Secondary-air pumprelay -J299Engine control unit 2-J624Engine control unit 1-J623SSP268_11121

Engine sub-systemsOperation of the secondary-air system andthe individual components is described indetail in SSP 217 on Page 32 onwards.Discharge of secondaryair directly at exhaustvalveFrom combination valvefor secondary-air systemDuct routingin exhaust manifoldSecondary-air ductSSP268_076A special feature of the secondary-air systemis that the secondary air is routed by way ofducts in the exhaust manifolds back to thesecondary-air ducts in the cylinder head.The secondary-air ducts in the cylinder headroute the secondary air directly behind theexhaust valves.22

Vacuum systemSystem layoutCombination valvefor secondary-airsystemCombination valvefor secondary-air systemSecondary-airpumpmotor 2 -V189Secondary-air pumpmotor -V101Secondary-airinlet valve 2-N320Secondary-airinlet valve-N112VacuumreservoirJ624J623VacuumreservoirNon-returnvalveActivatedcharcoalfiltersolenoidvalves -N80and -N333Crankcasebreather fumes(from oil tank)Secondary-air pumprelay -J299Secondary-airpump relay 2 -J545Activated charcoalfilterIntakemanifoldFuelpressureregulatorTovacuumreservoirExhaust flap 1valve -N321SSP268_160Exhaust flapN320N112Non-return valve23

Engine sub-systemsExhaust-gas recirculationAs exhaust-gas recirculation is implementedby way of the valve overlap (internal EGR), it isdealt with in the Section on Camshaft timingcontrol in SSP 267.The appropriate description can be foundin SSP 267 on Page 54 onwards.SSP267_11724

Fuel tank breather system -activated charcoal filter (ACF)FuelreturnFuelsupplyACF breatherSSP268_100Activated charcoal filtersolenoid valve -N80Activated charcoal filtersolenoid valve 2 -N333Activated charcoalfilter in rear left wheelhousingSSP268_15725

Engine managementEngine managementconceptEngine control unit 2 -J624 Engine control unit 1 -J623BOSCH BOSCHBOSCHBOSCHSSP268_129The engine management system for the W12engine - Motronic ME7.1.1 - takes the form ofa so-called twin control unit concept.The two control units are fully identical andeach is assigned to one cylinder bank. Thismeans that the two cylinder banks are to beviewed as separate engines.Certain sub-functions are however commonto both control units:– Engine control unit 1 -J623for cylinder bank 1– Engine control unit 2 -J624for cylinder bank 2The Motronic ME7.1.1 engine managementsystem is a more advanced version of theMotronic ME7.1, which was described in SSPs198 and 217.Relevant information can be found as follows:– Torque-oriented engine management (SSP198, Page 33 onwards)– Electrically operated throttle valve(electronic throttle function - SSP 198,Page 36 onwards; SSP 217, Page 42)– Sensors (SSP 198, Page 49 onwards)– Rapid starting functions (SSP 217,Page 40 onwards)– Engine run-out detection (SSP 217,Page 41)Control unit/cylinder bank assignmentidentification is provided by way of so-calledpin encoding in the wiring harness. Toprovide a clear distinction, the wiring harnessto each control unit is wound with differentlycoloured tape.Pin encoding means that the interface pin 49of engine control unit 1 -J623 is connected toterminal 15 and pin 49 of engine control unit2 -J624 is connected to terminal 31.On account of the twin control unit conceptattention must be paid to the following: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 selfdiagnosis… have the same encoding26

The following functions are implemented solelyby engine control unit 1 -J623:– Determination of specified speed values foridling speed control– Coolant temperature regulation, continuedcoolant circulation, actuation of continuedcoolant circulation pump -V51 and hydraulicfan– Provision of CAN data for drive system CAN– Actuation of fuel pump relay -J17 andMotronic current supply relay -J271– Control of exhaust flapProcessing of the following interfaces:– Brake light/pedal switches -F/-F47 (refer toSSP 198, Page 56)– Coolant temperature sender -G62(refer to Page 32)– Cruise control system switch -E45– AC high-pressure signal from air-conditionerpressure switch -F129– Terminal 50 signal– Engine speed signalFor further details, refer to "Additional signals/interfaces", Page 43 onwards.K50The following functions are implemented solelyby engine control unit 2 -J624:– Detection of combustion missing– Processing of oil temperature sender -G8signal (refer to Page 42)SSP268_148Engine control unit 2 -J624 Engine control unit 1 -J623Terminal 31Terminal 1527

Engine managementSystem layoutMotronic ME7.1.1Sensors/actuatorsLambda probe/Lambda probe 2-G39/-G108Accelerator position/accelerator pedal positionsender -G79/-G185Lambda probe/Lambda probe 2after catalyst -G130/-G131Air-mass meter -G70Intake-air temperaturesender -G42DrosselklappensteuereinheitJ338Engine control unit 1-J623Cruise controlsystemswitch -E45Temperature sensor forradiator fandrive circuit -G382Additional signalsCamshaft positionsenders-G40 (inlet)-G300 (exhaust)Knock sensors 1 + 2-G61/-G66Enginespeedsender -G28Brake light switch -FCruise control system brakepedal switch -F47Coolant temperaturesenders -G2/-G62Pin 49 toterminal 15DiagnosticconnectionThrottle valve controlpart 2 -J544Enginespeedsender -G28Lambda probes 3/4-G285/-G286Lambda probe 3/Lambda probe 4 aftercatalyst -G287/-G288Drivesystem CANAdditionalsignals28Oil temperaturesender -G8Air-massmeter 2 -G246Intake-air temperaturesender 2 -G299Camshaft positionsenders-G163 (inlet)-G301 (exhaust)Knock sensors 3 +4-G198/-G199Pin 49 toearthEngine control unit 2-J624

Throttle valvecontrol part -J338Ignition coils with outputstage -N70, 127, 291, 292,323, 324Injectors-N30, 31, 32, 33, 83, 84Motroniccurrent supplyrelay -J271Secondary-air inletvalve -N112Activated charcoal filtersolenoid valve -N80Map-controlled enginecooling thermostat -F265AdditionalsignalsExhaust flap 1valve -N321Electrohydraulic enginemounting solenoid valve,right -N145Camshaftadjustmentvalves-N205 (inlet)-N318 (exhaust)Additional coolantpump relay -J496with continuedcoolant circulationpump -V51Radiator fanvalve -N313Secondary-air pump relay-J299 with secondary-airpump motor -V101Fuel pumprelay -J17 withfuel pump -G6Radiator fanrun-on relay-J397Throttle valvecontrol part 2 -J544Ignition coils withoutput stages -N325, -N326,-N327, -N328, -N329, -N330Injectors -N85, 86, 299,300, 301, 302Secondary-air inletvalve 2 -N320SSP268_119AdditionalsignalsElectrohydraulic enginemounting solenoid valve,left -N144Activated charcoal filtersolenoid valve 2 -N333Secondary-air pump relay 2-J545 with secondary-airpump motor 2 -V189Camshaftadjustment valves-N208 (inlet)-N319 (exhaust)29

Engine managementBlock diagram3015XMotronic ME7.1.1Additional signalsJ17AE45FF47F265BatteryCruise control system switchBrake light switchCruise control system brake pedalswitchMap-controlled engine coolingthermostatG2 Coolant temperature senderG6 Fuel pumpG8 Oil temperature senderG28 Engine speed senderG39 Lambda probeG40 Inlet camshaft position sender/cylinder bank 1G42 Intake-air temperature senderG61 Knock sensor 1G62 Coolant temperature senderG66 Knock sensor 2G70 Air-mass meterG79 Accelerator position senderG108 Lambda probe 2G130 Lambda probe after catalystG131 Lambda probe 2 after catalystG163 Inlet camshaft position sender/cylinder bank 2G185 Accelerator pedal positionsender 2G186 Throttle valve drive(electric throttle operation)G187 Throttle valve drive angle sender 1(electric throttle operation)G188 Throttle valve drive angle sender 2(electric throttle operation)G198 Knock sensor 3G199 Knock sensor 4G246 Air-mass meter 2G285 Lambda probe 3G286 Lambda probe 4G287 Lambda probe 3 after catalystG288 Lambda probe 4 after catalystG296 Throttle valve drive 2G297 Angle sender 1 for throttle valvedrive 2G298 Angle sender 2 for throttle valvedrive 2G299 Intake-air temperature sender 2G300G301G382Exhaust camshaft position sender/cylinder bank 1Exhaust camshaft position sender/cylinder bank 2Temperature sensor for radiator fandrive circuitJ17 Fuel pump relayJ271 Motronic current supply relayJ299 Secondary-air pump relayJ338 Throttle valve control partJ397 Radiator fan run-on relayJ496 Additional coolant pump relayJ544 Throttle valve control part 2J545 Secondary-air pump relay 2J623 Engine control unit 1J624 Engine control unit 2M9M10Brake light bulb, leftBrake light bulb, rightN30 Injector, cylinder 1N31 Injector, cylinder 2N32 Injector, cylinder 3N33 Injector, cylinder 4N70N80Ignition coil 1 with output stageActivated charcoal filtersolenoid valveN83 Injector, cylinder 5N84 Injector, cylinder 6N85 Injector, cylinder 7N86 Injector, cylinder 8N112 Secondary-air inlet valveN127 Ignition coil 2 with output stageN144 Electrohydraulic engine mountingsolenoid valve, leftN145 Electrohydraulic engine mountingsolenoid valve, rightN205 Camshaft adjustment valve 1N208 Camshaft adjustment valve 2N291 Ignition coil 3 with output stageN292 Ignition coil 4 with output stageN299 Injector, cylinder 9N300 Injector, cylinder 10N301 Injector, cylinder 11N302 Injector, cylinder 12N313 Radiator fan valveN318 Exhaust camshaft controlvalve 1N319 Exhaust camshaft controlvalve 2N320 Seconday-air inlet valve 2N321 Exhaust flap 1 valveN323 Ignition coil 5 with final output stageN324 Ignition coil 6 with final output stageN325 Ignition coil 7 with final output stageN326 Ignition coil 8 with final output stageN327 Ignition coil 9 with final output stageN328 Ignition coil 10 with final output stageN329 Ignition coil 11 with final output stageN330 Ignition coil 12 with final output stageN333 Activated charcoal filter solenoidvalve 2SFusesV51 Continued coolant circulation pumpV101 Secondary-air pump motorV189 Secondary-air pump motor 2Colour code= Input signal= Output signal= Positive supply= Earth= CAN BUS123456789ABCDEX{{Terminal 50To radiator fan run-on relay -J397AC high-pressure signal fromair-conditioner pressure switch -F129(high-pressure switch)AC requirement signal(from air-conditioner control unit -E87)Compressor "ON/OFF" signalCrash signalEngine speed signalCAN Low/driveCAN High/drivePower supply fromFuel pump relay -J17Power supply fromMotronic current supplyrelay -J271Connections withinblock diagramA31SS+-MG6EN30S S SC BN31 N32 N33 N83 N84N70PQS15XA49N127N145DN291N318 N205 N112 N80 N321N292150 1 2 2a0,2aN323N313DN324CC-+m LG70/G42MSJ299V10131G30

3015XJ27115S S S SSSG130-λλG131AD C CJ338F265 G382DEJ544G186 G187 G188G296 G297 G298G198 G199 G8t°F47FJ397J496J545EN144 N319 N208 N320 N3338 9N301N302N86 N299 N300M9N85M V51M V189M10 DX3131J623J624+ - + -- +-BCBBE+ + ++ +λλP NP N m Z Z 1 2 3L P NN326N327N328N329N330P N Z Z 4 5 6 7ZZ ZZG66 G61 G62 G2 G40 G300 G28G79 G185N325G39G246/G299G163 G301G108G287 G288G285G286M+-M+-49PQ31

Engine managementSpecial features ofMotronic ME7.1.1The Motronic ME7.1.1 is a more advancedversion of the Motronic ME7.1.Important new features:– Greater computer capacity on account ofnew computer-bound sub-functions– Extension of control unit activities afterswitching off ignition with the aid of mainrelay concept– Infinitely variable adjustment of inlet andexhaust camshafts (refer to SSP 267,Page 59 onwards)– Designed for coolant temperature regulation– Enhanced evaluation of signals from coolanttemperature sender -G62– Management of additional and new CANmessages (refer to Page 44)– Designed to suit new wide-band Lambdaprobes upstream of catalytic converter(refer to Page 14)-G62 evaluationPrecise determination of the coolanttemperature in the lower operatingtemperature range is required for cold startingand subsequent warm-up.Switching to the evaluation circuit for the uppertemperature range takes place as of a coolanttemperature of approx. 50 °C.32Coolant temperature regulation demandsexact recognition of the coolant temperaturein the upper operating temperature range.Precision sensing of the coolant temperatureover a broad temperature range musttherefore be of a very high standard.For physical reasons, the characteristic curveof -G62 (NTC sender) is highly degressive overthe temperature range to be recorded (approx.-30 °C to + 120 °C). At the same time thecoefficient of resistance ranges from approx.25 000 ohms to approx. 115 ohms.The change in resistance per °K thus 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 one.R NTC [W]3210 48643210 38643210 28-30 -20 0 20 40 60 80 100 120SSP268_190u [°C]

Main relay conceptTo date, the power supply for the sensors andactuators was provided largely via the fuelpump relay -J17.A new addition is the Motronic current supplyrelay -J271 (main relay).As with the fuel pump relay -J17, the Motroniccurrent supply relay -J271 is actuated byengine control unit 1. Thanks to the Motroniccurrent supply relay -J271, the engine controlunits can still implement certain functionsafter the engine has been switched off(ignition OFF).The following sensors/actuators are suppliedwith power by the Motronic current supplyrelay -J271:– Engine control unit 1– Engine control unit 2– Ignition coils of cylinder bank 1– Ignition coils of cylinder bank 2– Camshaft adjustment valves– Engine mounting solenoid valves– Radiator fan valve -N313– Additional coolant pump relay -J496(continued coolant circulation pump -V51)– Radiator fan run-on relay -J397(radiator fan -V7)– Map-controlled engine cooling thermostat-F265After switching off the ignition, the ignitioncoils continue to be actuated until the enginestops in order to ensure ignition of the fuelalready injected. This means that nounburned fuel/air mixture reaches theexhaust system, thus reducing the level ofexhaust emissions.The camshaft adjustment valves also remainactuated until the engine stops followingignition switch-off to ensure that thecamshafts are kept in the appropriateposition until the engine has stopped.The engine mounting solenoid valves areactuated to provide smooth, vibration-freeengine shutoff.The solenoid valve for the hydraulic fan isactuated to prevent brief fan speed increase.Refer to block diagramon Page 30.As engine control unit 1 is responsible forcontrol of the entire continued coolantcirculation process, it must be possible toactuate the control elements (relay -J496,relay -J397 and thermostat -F265).33

Engine managementEngine speed sender -G28The engine speed sender supplies the mostimportant engine management input signal.The engine will not run in the event of -G28failure.Previous knowledge of the way in whichHall sensors work is required forunderstanding of this Section.Further details can be found in pertinentmotor vehicle engineering reference works.The absence of a signal from -G28 isrecognised by the self-diagnosis function.In view of the twin control unit concept andthe high dynamic requirements (real time) forthe engine speed signal, the engine speedsender -G28 is connected directly to bothengine control units.The sensor used is a so-called "differentialHall sensor" with integrated permanentmagnet which is suitable for scanningferromagnetic sender wheels.SSP268_164J623J624-G28 Engine speed sender-G40 Inlet camshaft positionsender/cylinder bank 1+ + + + +-G163 Inlet camshaft positionsender/cylinder bank 2G40 G300 G28 G163 G30131SSP268_159-G300 Exhaust camshaft positionsender/cylinder bank 1-G301 Exhaust camshaft positionsender/cylinder bank 234

Engine speed sender -G28SSP268_167Evaluation electronicsNPermanent magnetSHall element 1 Hall element 2Rotor(sender wheel)Magnetic lines of forceSSP268_16835

Engine managementSensor designSignals are generated by two Hall elementsarranged behind one another with respect tothe sender wheel.Output signalLocated above the two Hall elements andintegrated into the sensor is a permanentmagnet, the field of which acts on the Hallelements. The integrated evaluationelectronics - also referred to as Hall IC -evaluate the Hall voltages of the two Hallelements and generate the sensor outputsignal.Hall elements react to changes in themagnetic field. The sender wheel takes theform of a rotor and influences both the fieldstrength of the permanent magnet and theHall voltages of the two Hall elements.HE1NSHE2Hall voltage U HEU HE1 U HE2SSP268_194If the rotor (ferrous metal) is located directlybeneath the Hall elements, the ferrous metalwill intensify the magnetic field in the area ofthe Hall elements. The Hall voltage of the twoHall elements increases with increasingmagnetic field strength.The fact that the two Hall elements arearranged behind one another leads todiffering Hall voltage levels at the Hallelements at the transition from rotor to gap(or vice versa).NSHall voltage U HEU HE1U HE2SSP268_195The resultant difference between and themagnitude of the Hall voltages are used forevaluation and generation of the outputsignal.NU HE1U HE2IC stands for "integrated circuit" and refersto an integrated semi-conductorcircuit.SHall voltage U HESSP268_19636

Camshaft position sendersIn addition to the main purpose of definingthe camshaft position with respect to theposition of the crankshaft, one camshaftposition sender each is required for inlet andexhaust camshaft adjustment.Sender signals are required for the followingfunctions:– -G28 and -G40Synchronisation of bank 1 (with cylinder 1/cylinder 6) for knock control andsequential injection-G300 is responsible for synchronisation inthe event of failure of -G40.– -G28 and -G163Synchronisation of bank 2 (with cylinder12/cylinder 7) for knock control andsequential injection– -G28 and -G40/300Control and monitoring of camshaftadjustment for cylinder bank 1– -G28 and -G163/301Control and monitoring of camshaftadjustment for cylinder bank 2There is no camshaft timing controlfunction if one of the camshaft positionsenders is defective.In the event of failure of both the camshaftposition senders of one bank, enginestarting is enabled by the engine run-outdetection function.Adaption of sender signals -G40/-G300/-G163and -G301 provides more accuratedetermination of the camshaft basicpositions (for more information, refer to SSP267 - Part 1, Section on "Camshaft timingcontrol", Page 54).-G301 is responsible for synchronisation inthe event of failure of -G163.Bank 2 synchronisation is offset by 60° withrespect to bank 1. The pin encoding ensuresthat allowance is made for this in thesoftware.Cylinder bank 2Cylinder bank 1Hall sender 4-G301Hall sender 2-G163SSP268_147Hall sender-G40Hall sender 3-G30037

Engine managementSensor designAs already described for the engine speedsender -G28, the camshaft position sender isalso a so-called "differential Hall sensor".The camshaft position senders employ a twotrackrapid start sender wheel made offerrous metal.The sender wheel has two broad and twonarrow rotors/gaps.This design, featuring different rotor widths,enables the signal profile of -G40/-G163together with that of sender -G28 to be usedfor more rapid determination of camshaftadjustment with respect to the crankshaft.Track 1 Track 2Camshaft positionsenderHall element 2Hall element 1PermanentmagnetSSP268_14938

A further feature of the sender 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 Hallelements HE1 and HE2 arranged next to oneanother with respect to the sender wheel.One track is assigned to each of the Hallelements.Located above the two Hall elements andintegrated into the sensor is a permanentmagnet, the field of which acts on the Hallelements. The integrated evaluationelectronics - also referred to as Hall IC -evaluate the Hall voltages of the two Hallelements and generate the sensor outputsignal.Hall elements react to changes in themagnetic field. The sender wheel is of twotrackdesign and influences the strength ofthe permanent magnet.When the rotor (ferrous metal) of track 1 islocated directly beneath HE1, there is a gapunder HE2. The ferrous metal intensifies themagnetic field in the area of HE1 and the Hallvoltage of HE1 increases with respect to HE2.The difference between HE1 and HE2 and themagnitude of the two Hall voltages are usedfor evaluation and generation of the outputsignal.Hallelement 2Hallelement 1Track 2Track 1SSP268_150SNSSP268_193SSP268_151Permanent magnet39

Engine managementEngine speed sender-G28Softwarereference mark660°78°138°720°0° 60° 120° 180°240°ITDC 9 ITDC 1 ITDC 12 ITDC 5 ITDC 8 ITDC 36° CS114° CS/Inlet in reference position (retard)Inlet camshaft-G40/-G16352° maximum advance92° CS/Exhaust in reference position (retard)Exhaust camshaft-G300/-G30140° CS22° maximum advance140° CS40° CS40° CSThe signal profiles of the camshaft positionsenders are identical for both inlet andexhaust camshafts of cylinder banks 1 and 2(same distance from software referencemark).Basic synchronisation of the first ignition TDC(ITDC) of cylinder bank 1 (cylinder 1) takesplace 78° after the software reference mark.On account of the special features of theengine mechanical and managementsystems, basic synchronisation of the firstignition TDC (ITDC) of cylinder bank 2(cylinder 12) takes place 138° after thesoftware reference mark.Allowance is made for this in the control unitand it is specified by the pin encoding.40

Softwarereference mark300° 360° 420° 480° 540° 600°ITDC 10ITDC 6ITDC 7ITDC 2ITDC 11ITDC 4140° CS40° CS140° CSSSP268_085Use is made as engine speed sender of aHall sensor.The software reference mark is the 2ndtrailing edge after the gap (60-2 system).The camshafts are in "retard" position if thecamshaft adjustment valves are deenergisedwhen the engine is running. If there is no oronly insufficient oil pressure, the camshaftsare also set to retard position on account ofthe chain pull.41

Engine managementOil temperature sender -G8The signal of the oil temperature sender -G8is evaluated by engine control unit 2 -J624and transmitted by way of CAN data transferto engine control unit 1 -J623.OiltankOil temperaturesender -G8It is used for calculating the specified coolanttemperature and the continued coolantcirculation time.To prevent overheating of the engine,mandatory change-up from 4th to 5th gear isimplemented on exceeding an engine oiltemperature of approx. 135 °C.The decrease in engine speed counteracts afurther increase in engine oil temperature.The mandatory change-up described abovealso takes place on exceeding a coolanttemperature of approx. 120 °C.Engine control unit 2 -J624Automatic gearboxcontrol unit -J217CANEngine control unit 1 -J623SSP268_145Detection of combustionmissingPlease refer to the notes given in the "Service"Section on Page 48.42

Notes43

Engine managementCAN data exchangeThe twin control unit concept has resulted inthe addition of new CAN messages, via whichthe two engine control units exchange data.Engine control unit 1 transmits information toengine control unit 2 by way of so-called"master-slave messages".So-called "slave-master messages" provideengine control unit 1 with data from enginecontrol unit 2.Although these messages are transmitted bymeans of the general drive system CAN, theyare only used for the exchange of databetween the two engine control units.Engine control unit 2 can only transmitby way of slave-master messages.Although engine control unit 2can transmit data to engine controlunit 1 and the dash panel insert(immobilizer), it is otherwise onlydesigned to receive data.Engine control unit 1(master control unit)– Intake-air temperature– Brake light switch 1– Brake pedal switch– Throttle valve angle– Electronic throttle warning lamp/info– Driver input torque– Fault status 1– Accelerator pedal position 1– CCS switch positions– CCS specified speed– Altitude information– Compressor switch-off– Compressor ON/OFF (feedbackfrom bidirectional interface)– Fuel consumption– Coolant temperature 1– Idling speed recognition– Engine shutoff position 2– Engine speed– ACTUAL engine torques– Emergency running programs(self-diagnosis information)– -G8 oil temperature warning– V max limit active 2– Immobilizer– Crash signal 2Data transmitted by the enginecontrol unitsData received and evaluated bythe engine control units1 These data are additionallytransmitted by way of masterslavemessages2 These data areonly transmitted by way ofmaster-slave messagesEngine control unit 2(slave control unit)– EPC fault lamp request 3– OBD fault lamp request 3– Misfiring detection 3– Fault status 3– Oil temperature (from -G8) 3– Immobilizer 33 These data areonly transmitted by way ofslave-master messages44

Gearbox control unit– Torque gradient limitation(converter/gearbox protection)– Idle regulation adaption release– Compressor switch-off– Specified idling speed– Current gear/target gear– SPECIFIED engine torque– Emergency running programs (selfdiagnosisinformation)– Gearshift active/not active– Selector lever position– Torque converter clutch statusDrive system CAN HighDrive system CAN LowESP/ABS control unit– TCS request– SPECIFIED TCS intervention torque– Brake pedal status– ESP intervention– Overrun torque limiting functionrequest– Overrun torque limiting functionintervention torqueDash panel insert– Self-diagnosis information– Vehicle speed– Coolant temperature– Immobilizer (from both enginecontrol units)Steering angle sensor– Steering wheel angle(used for idling speed pilotcontrol and engine torquecalculation on the basis of powersteering power requirement)45

Engine managementAdditional signals/interfacesIn addition to CAN BUS data exchange, the following signals are relayed via separateinterfaces.Pin 42 Terminal 50 ECU* 1 onlyPin 67 Crash signal ECU 1 and ECU 2Pin 41 AC compressor signal ON/OFF ECU 1 and ECU 2Pin 40 AC requirement signal ECU 1 and ECU 2Pin 54 Air-conditioner high-pressure switch signal ECU 1 onlyPin 37 Engine speed signal ECU 1 onlyPin 49Pin encoding of control units+ to pin 49 = engine control unit 1- to pin 49 = engine control unit 2Pin 43 K-wire/diagnosis ECU 1 and ECU 2Pin XX Interfaces - cruise ECU 1 onlycontrol system, refer to Page 47* ECU = Engine control unitTerminal 50 signalThe engine run-out detection function (referto SSP 217, Page 41) can recognise"reversing" in the course of the engineshutoff process. As reversing of the enginecan be ruled out on starting, the terminal 50information (starter operated) is used forchecking the plausibility of and evaluatingthe reversing detection function.Air-conditioner compressor ON/OFF signalFor a detailed description, refer to SSP 198,Page 59.The compressor ON signal is also used as asource of information for calculating thespeed of the hydraulic fan.Air-conditioner high-pressure switch signalThe signal from the air-conditioner pressureswitch -F129 (high pressure) providesinformation for actuating the hydraulic fan(refer to Page 8 onwards). When the highpressureswitch is closed (approx. 16 bar),both maximum electric fan speed andmaximum hydraulic fan actuation are set.Crash signalFor a detailed description, refer to SSP 217,Page 47.Although ECU 1 switches the fuel pump, thecrash signal is also transmitted to ECU 2.In addition to powering the fuel pump, thefuel pump relay is also responsible forsupplying voltage to other actuators of bothECUs (refer to block diagram).The crash signal in ECU 2 suppressesunwanted entries in the fault memory such aswould be caused by deactivation of the fuelpump.As of software version 0004, the crash signalis transmitted by means of a master-slavemessage. The pin 67 interface is no longerevaluated. To avoid unnecessary expense, nomodifications have been made to the wiringharness (wiring to pin 67 interface still exists).46

Air-conditioner requirement signalFor a detailed description, refer to SSP 217,Page 48.Engine speed signalFor a detailed description, refer to SSP 198,Page 60.Numerous control units require engine speedinformation for calculation purposes. In themajority of cases, the engine speedtransmitted by way of the CAN messagesuffices.The engine speed is one of the mostimportant information parameters forgearbox control, with a high standard ofresolution and transmission speed beingrequired.The output signal (square-wave signal)generated by engine control unit 1 satisfiesthese requirements.FIXSet/decelerate1 0 2aACTIV ON OFFSSP268_189Cruise control system (CCS) interfacesFor a detailed description, refer to SSP 198,Page 61.Pin 38Pin 57Pin 75Pin 76ON/OFF with erasing of memory(master switch)Set/decelerateReactivate/accelerateOFF without erasing of memory57 38 76 75J62315SwitchpositionFunction0 ON3 4 6 1 2 51 ReactivationAccelerate/set2 OFF - without erasing ofmemory2aOFF - with erasing ofmemory0 1 2 2a0,2aSSP268_19147

Engine oil changeIn view of the dry sump lubrication, it isalways necessary to open both oil drain plugs(sump and oil tank) to drain off the engine oil.The use of an oil extractor is not possible withthe W12 engine.The W12 engine is only to be filled withLongLife engine oil as per VW Standard50301.Oil drainplugOil drain plugat oil filterOil drainplugThe oil filler neck leads into the crankcasebreather pipe from the cylinder heads to theoil tank.The procedure for checking the oil level isdescribed in SSP 267 - Part 1, Page 30onwards.Please also heed the relevant additionalinformation given in the Maintenancemanual.SSP268_165Crankcase breather pipeDipstickOil filler neckOil tankSSP268_17649

ServiceWorkshop equipment/special toolsListed in the following are the new items ofworkshop equipment and special toolsdesigned for the W12 engine.VAS 6100 Workshop craneWith a loadbearing capacity of 1200 kg, theworkshop crane VAS 6100 is designed tohandle the new large-volume engines (e.g. V8TDI, W12) as well as future developments.SSP268_186Extension VAS 6101 (load bearing capacity300 kg) is available as an option.VAS 6095 Engine and gearbox assemblymountIn addition to the generously designedloadbearing capacity of 600 kg, VAS 6095offers two major new features.Unit mounting with the aid of universallyadjustable clamps in combination with thelocating pins provides ease of access to theback of the engine (e.g. when working ontiming mechanism).Work is facilitated by being able tohydraulically adjust the height of the unit byapprox. 200 mm.The tilt mechanism enables the unit to beeasily moved into any angular positionrequired. The mechanism is self-locking sothat there is no need for separate fixing.SSP268_184The integrated storage facilities and slidingdrip tray for collecting fluids round off thepractical design of this item.VAS 6095 is compatible with existing engineand gearbox supports.Locating pinSSP268_18250

Unit assembly trolleyStill at the development stage is a unitassembly trolley for simple and reliableperformance of all engine and gearbox preassemblywork.The work table is in two sections to facilitateseparation and joining of engine andgearbox.The unit assembly trolley will be universallyapplicable and is expected to be available inthe 1st quarter of 2002.SSP268_185V.A.G 1342/15 Oil pressure test adapter withV.A.G 1342/16 Oil pressure test pipe sectionClampsSSP268_187SSP268_18151

All rights reserved. Subject totechnical modification.AUDI AGDepartment I/VK-35D-85045 IngolstadtFax 0841/89-36367140.2810.87.20Technical status as at 11/01Printed in Germany268