Vw tdi with_pumpe_duse


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Vw tdi with_pumpe_duse

  1. 1. 1.9-Liter TDI Enginewith Pump Injection(Pumpe Düse)Design and FunctionSelf-Study ProgramCourse Number 841303
  2. 2. Volkswagen of America, Inc.Service TrainingPrinted in U.S.A.Printed 10/2003Course Number 841303©2003 Volkswagen of America, Inc.All rights reserved. All information containedin this manual is based on the latestinformation available at the time of printingand is subject to the copyright and otherintellectual property rights of Volkswagen ofAmerica, Inc., its affiliated companies and itslicensors. All rights are reserved to makechanges at any time without notice. No partof this document may be reproduced,stored in a retrieval system, or transmittedin any form or by any means, electronic,mechanical, photocopying, recording orotherwise, nor may these materials bemodified or reposted to other sites withoutthe prior expressed written permission ofthe publisher.All requests for permission to copy andredistribute information should be referredto Volkswagen of America, Inc.Always check Technical Bulletins and theVolkswagen Worldwide Repair InformationSystem for information that may supersedeany information included in this booklet.Trademarks: All brand names and productnames used in this manual are trade names,service marks, trademarks, or registeredtrademarks; and are the property of theirrespective owners.
  3. 3. iTable of ContentsThe Self-Study Program provides you with informationregarding designs and functions.The Self-Study Program is not a Repair Manual.For maintenance and repair work, always refer to thecurrent technical literature.Important/Note!New!Introduction ...............................................................................11.9-Liter TDI Engine with Pump Injection SystemEngine – Mechanics ..................................................................2Development of the 1.9-Liter TDI Engine with PumpInjection System, Technical Data – 1.9-Liter TDI Enginewith Pump Injection System, Trapezoidal Piston andConnecting Rod, Toothed Belt DriveFuel Supply ................................................................................8Fuel Supply System Overview, Fuel Pump,Distributor Pipe, Fuel Cooling SystemPump Injection System ..........................................................15Pump/Injectors, Design, Injection CycleEngine Management...............................................................281.9-Liter TDI Engine EDC 16 System Overview,Sensors, ActuatorsGlow Plug System ..................................................................53Glow Plug SystemFunctional Diagram.................................................................54EDC 16 Functional Diagram for 1.9-Liter TDI EngineService......................................................................................56Self-Diagnosis, Pump/Injector Adjustment, Special ToolsKnowledge Assessment .........................................................61
  4. 4. Introduction11.9-Liter TDI Engine withPump Injection SystemThe demands on the modern diesel enginefor increased performance and fueleconomy, and reduced exhaust emissionsand noise levels are growing constantly.Good fuel and air mixture preparation is akey factor in meeting these requirements.This calls for efficient injection systems thatproduce high injection pressures to ensurethat the fuel is well atomized. It is alsonecessary to precisely control the start offuel injection and the injection quantity.The pump injection system meetsthese requirements.In 1905, Rudolf Diesel came up with theidea of a pump/injector, combining theinjection pump and injector in one unitin order to dispense with high-pressurelines and achieve high injection pressures.At the time, however, he did not havethe technical means to put his ideainto practice.Diesel engines with mechanically controlledpump injection systems have been in usein ships and trucks since the 1950s.In association with Bosch, Volkswagen hassucceeded in developing a diesel enginewith a solenoid valve controlled pumpinjection system suitable for use inpassenger cars.The 1.9-liter TDI engine with the new pumpinjection system meets the stringentdemands for improved performance andcleaner emissions.With continuing advances like this one,Rudolf Diesel’s vision of “smoke- andodor-free exhaust gases” may one daybecome a reality.SSP304/032SSP209/027
  5. 5. Engine – Mechanics2Development of the1.9-Liter TDI Engine withPump Injection SystemThe new 100 bhp (74 kW) 1.9-liter TDIengine with pump injection system wasdeveloped from the existing 109 bhp (81kW) 1.9-liter TDI engine with a distributorinjection pump and no intermediate shaft.The pump injection system comprises theonly significant difference between thetwo engines.This Self-Study Program concernsthe design and function of the new pumpinjection system, and the modificationsto the fuel system, engine managementsystem, and engine mechanicalcomponents to accommodate the system.A diesel engine with the pump injectionsystem has the following advantages overan engine with a distributor injection pump:• Low combustion noise.• Low fuel consumption.• Clean emissions.• High efficiency.These advantages are attributable to:• The high injection pressures of up to27,846 psi (192,000 kPa / 1,920 bar).• Precise control of the injection cycle.• The pre-injection phase.SSP209/005
  6. 6. Speed (rpm)3Engine – MechanicsTechnical Data –1.9-Liter TDI Engine withPump Injection System• Engine codeBEW• TypeFour-cylinder in-line engine with twovalves per cylinder• Displacement115.7 cu in (1,896 cm3)• Bore3.13 in (79.5 mm)• Stroke3.76 in (95.5 mm)• Compression ratio19.0 : 1• Maximum power output100 bhp (74 kW) @ 4000 rpm• Maximum torque177 lbs-ft (240 Nm) @ 1800 to 2400 rpm• Engine managementEDC 16• Firing sequence1-3-4-2• Emission ControlBin 10 EPA Federal Emissions Concept,OBD II, catalytic converter, water-cooledEGR systemSSP209/006TorqueOutput1000 2000 3000 4000 5000lbs-ft Nm221 300184 250148 200111 15074 10037 500hp kW121 90101 7580 6060 4540 3020 150
  7. 7. 4Engine – MechanicsTrapezoidal Pistonand Connecting RodTo accommodate the higher combustionpressures in the 1.9-liter TDI engine withpump injection system than areencountered in the base engine, the pistonhub and the connecting rod eye aretrapezoidal in shape.SSP209/007
  8. 8. 5Engine – MechanicsThis distributes the combustion forces overa larger area and relieves the load on thepiston pin and connecting rod.In comparison with the conventionalparallelogram-shaped link between thepiston and connecting rod, the trapezoidalconnecting rod eye and piston hub have alarger contact surface area at the piston pinowing to their shape.SSP209/008Combustion ForceContact SurfaceForce Distribution in a Parallelogram-ShapedPiston and Connecting RodForce Distribution in a Trapezoidal Pistonand Connecting RodCombustion ForceContact SurfaceSSP209/009
  9. 9. Toothed Belt DriveHigh pump forces are required to generatehigh injection pressures of up to 27,846 psi(192,000 kPa / 1,920 bar).These forces subject the components ofthe toothed belt drive to high loads.To relieve the load on the toothed belt,several modifications have been made.• A vibration absorber integrated in thecamshaft gear reduces vibration inthe toothed belt drive.• The toothed belt is about 0.20 inch(5 mm) wider than the toothed belt usedin the base engine. Higher forces can betransmitted by the larger surface area.• A hydraulic tensioner keeps thetoothed belt evenly tensioned indifferent load states.• Some of the teeth on the crankshafttiming belt gear have a larger gapclearance to reduce toothed belt wear.SSP209/089SSP209/88GapClearance To relieve the load on the toothed beltduring the injection cycle, the crankshafttiming belt gear has two pairs of teeth witha larger gap clearance than the other teeth.6Engine – Mechanics
  10. 10. FunctionDuring the injection cycle, the highpumping forces exert a heavy load on thetoothed belt.The camshaft timing belt gear is sloweddown by the pumping forces. At the sametime, the combustion process speeds upthe crankshaft timing belt gear. The toothedbelt is stretched and the pitch is temporarilyincreased as a result.Because of the engine firing order, thisstretching process occurs at regularintervals and the same teeth on the timingbelt gear are in mesh with the toothed beltevery time.Non-uniform tooth gap clearanceOn the 1.9-liter TDI engine with pumpinjection system, the crankshaft timing beltgear teeth have a larger gap clearance atthese points to compensate for the changein belt tooth pitch and thus reduce toothedbelt wear.SSP209/0917Deceleration ForceAcceleration ForcePitchEngine – Mechanics
  11. 11. 8Fuel SupplyFuel Supply System OverviewA mechanical fuel pump sucks the fuel outof the fuel tank through the fuel filter andpumps it along the supply line in thecylinder head to the pump/injectors.Fuel Cooler – Cools the returning fuelto prevent excessively hot fuel frombeing routed back to the fuel tank.The fuel that is not required for injection isreturned to the fuel tank via the return linein the cylinder head, a fuel temperaturesensor, and a fuel cooler.Non-Return Valve – Prevents fuelfrom the fuel pump flowing back intothe fuel tank while the engine is notrunning. It has an opening pressureof 2.9 psi (20 kPa / 0.2 bar).Fuel Filter – Protects the injectionsystem against contamination andwear caused by particles and water.Fuel Temperature Sensor G81 –Determines the temperature of thefuel in the fuel return line and sends acorresponding signal to the Diesel DirectFuel Injection Engine Control Module J248.Fuel Tank
  12. 12. 9Fuel SupplySSP209/018Fuel Return Line PressureLimiting Valve – Keeps thepressure in the fuel return lineat 14.5 psi (100 kPa / 1 bar).This maintains a forceequilibrium at the pump/injector solenoid valve needle.Strainer – Collects vapor bubbles in thefuel supply line. These vapor bubbles arethen separated through the restrictorinto the return line.Fuel Supply Line Pressure Limiting Valve –Regulates the fuel pressure in the fuel supply line.The valve opens when the fuel pressure exceeds109 psi (750 kPa / 7.5 bar). Fuel is routed back tothe suction side of the fuel pump.Fuel Pump Rotor – Pumps the fuel fromthe fuel tank through the fuel filter andthe fuel supply line in the cylinder headto the pump/injectors.Restrictor – Located between thefuel supply line and the fuel returnline. Vapor bubbles in the fuel supplyline are separated through therestrictor into the fuel return line.Pressure Limiting Valve Bypass –If there is air in the fuel system,for example when the fuel tankis empty, the pressure limitingvalve remains closed. The air isexpelled from the system by thefuel flowing into the tank.Cylinder Head
  13. 13. There is a fitting on the fuelpump for connecting pressuregauge VAS 5187 to check thefuel pressure in the supply line.Please refer to the Repair Manualfor instructions.Fuel Supply10Fuel PumpThe fuel pump is located directly behindthe vacuum pump at the cylinder head.It moves the fuel from the fuel tank to thepump/injectors.Both pumps are driven jointly by thecamshaft. They are collectively known asa tandem pump.Fuel Return LineSSP209/049Pressure GaugeConnection FittingFuel PumpVacuum PumpFuel Supply Line
  14. 14. 11Fuel SupplyThe fuel pump is a blocking vane-cell pump.The blocking vanes are pressed against thepump rotor by spring pressure. This designenables the fuel pump to deliver fuel evenat low engine speeds.The fuel ducting system within the pumpis designed so that the rotor alwaysremains wetted with fuel, even if the tankhas been run dry. This makes automaticpriming possible.SSP209/050Blocking VanesRestrictorConnection forFuel Supply LineFuel Supply LinePressure Limiting ValveTo Fuel Supply Linein Cylinder HeadStrainerConnection forFuel Return LineFuel ReturnLine PressureLimiting ValveRotorFrom FuelReturn Line inCylinder Head
  15. 15. 12FunctionThe fuel pump operates by taking fuel in asthe pump chamber volume increases andpushing the fuel out under pressure as thechamber volume is reduced.The fuel is drawn into two chambers andpumped out from two chambers. Theintake and delivery chambers are separatedfrom one another by the spring-loadedblocking vanes and the pump rotor lobes.Fuel drawn into chamber 1 is pushed out atchamber 2. Fuel drawn into chamber 3 ispushed out at chamber 4.The rotation of the rotor increases thevolume of chamber 1 while the volume ofchamber 4 is simultaneously reduced.Fuel is pushed out of chamber 4 to thefuel supply line in the cylinder head.Fuel SupplyThe rotation of the rotor increases thevolume in chamber 3 as it reduces thevolume in chamber 2. Fuel drawn in atchamber 1 is forced out of chamber 2 tothe fuel supply line in the cylinder head.SSP209/052RotorChamber 4 Chamber 3Chamber 2Chamber 1SSP209/051Chamber 1RotorChamber 4Chamber 3Chamber 2
  16. 16. 13Fuel SupplyDistributor PipeA distributor pipe is integrated in the fuelsupply line in the cylinder head. It distributesthe fuel evenly to the pump/injectors at auniform temperature.In the supply line, the fuel moves throughthe center of the distributor pipe towardcylinder 1 at the far end.The fuel also moves through the crossholes in the distributor pipe and enters theannular gap between the distributor pipeand the cylinder head wall.This fuel mixes with the hot unused fuelthat has been forced back into the supplyline by the pump/injectors.This results in a uniform temperatureof the fuel in the supply line running toall cylinders.All pump/injectors are supplied withthe same fuel mass, and the engineruns smoothly.SSP209/039Cylinder HeadAnnular GapCross HolesCylinder 4Cylinder 3Cylinder 2Cylinder 1Distributor PipeSSP209/040SSP209/29Cross HolesMixing Fuel inAnnular GapFuel to Pump/InjectorFuel fromPump/Injector
  17. 17. 14Fuel SupplyFuel Cooling CircuitThe heated fuel returning from the pump/injectors flows through the fuel cooler andits heat transfers to the coolant in the fuelcooling circuit that also flows through thefuel cooler.The auxiliary water cooler reduces thetemperature of the coolant in the fuelcooling circuit by dissipating the heat inthe coolant to the ambient air.Pump for Fuel Cooler V166 is an electricrecirculation pump. It circulates the coolantin the fuel cooling circuit through theauxiliary water cooler and the fuel cooler. Itis switched on by the Diesel Direct FuelInjection Engine Control Module J248 viathe Relay for Pump, Fuel Cooling J445 ata fuel temperature of 158°F (70°C).The fuel cooling circuit is largely separatefrom the engine cooling circuit. This isnecessary because the temperature of thecoolant in the engine cooling circuit is toohigh to cool down the fuel when the engineis at operating temperature.The fuel cooling circuit is connected to theengine cooling circuit near the expansiontank. This enables replenishment of thecoolant for fuel cooling at the coolantexpansion tank. It also allowscompensation for changes in volume dueto temperature fluctuation.The fuel cooling circuit is connected so thatthe hotter engine cooling circuit does nothave a detrimental effect on its ability tocool the fuel.SSP209/048Fuel PumpPump forFuel CoolerV166Fuel CoolerAuxiliaryWaterCoolerEngineCoolingCircuitFuel TankCoolantExpansionTankFuelTemperatureSensor G81Fuel Cooling SystemThe high pressure generated by the pump/injectors heats up the unused fuel so muchthat it must be cooled before it gets back tothe fuel tank.A fuel cooler is located on the fuel filter.It cools the returning fuel and thus preventsexcessively hot fuel from entering the fueltank and possibly damaging the Sender forFuel Gauge G.
  18. 18. 15Pump Injection SystemPump/InjectorsA pump/injector is, as the name implies, apressure-generating pump combined with asolenoid valve control unit (Valves for Pump/Injectors, Cylinders 1 through 4, N240,N241, N242, and N243) and an injector.Each cylinder of the engine has its ownpump/injector.This means that there is no longer anyneed for a high-pressure line or a distributorinjection pump.SSP209/012Just like a conventional system with adistributor injection pump and separateinjectors, the new pump injectionsystem must:• Generate the high injectionpressures required.• Inject fuel into the cylinders in the correctquantity and at the correct point in time.Solenoid Valve Control UnitInjectorPressure-GeneratingPump
  19. 19. 16Pump Injection SystemThe pump/injectors are installed directly inthe cylinder head.SSP209/086SSP209/087They are attached to the cylinder head byindividual clamping blocks.It is important to ensure thatthe pump/injectors are positionedcorrectly when they are installed.Refer to the Repair Manualfor instructions.If the pump/injectors are not installedperpendicular to the cylinder head, thefasteners could loosen. The pump/injectorsor the cylinder head could be damaged asa result.ClampingBlock
  20. 20. 17Pump Injection SystemDesignSSP209/023Roller-TypeRocker ArmO-RingO-RingO-RingHeat-InsulatingSealCylinder HeadInjector NeedleInjector NeedleDamping ElementInjector SpringFuel Supply LineRetractionPistonFuel Return LineHigh-PressureChamberPump/InjectorSolenoid ValveSolenoidValve NeedleInjection CamPiston SpringPump PistonBall Pin
  21. 21. 18Pump Injection SystemDrive MechanismThe camshaft has four additional cams fordriving the pump/injectors.They activate the pump/injector pumppistons with roller-type rocker arms.Valve CamSSP209/015Injection Cam(Hidden byRocker Arm Roller)Roller-TypeRocker Arm
  22. 22. 19Pump Injection SystemThe gradual slope of the cam trailing edgeallows the pump piston to move uprelatively slowly and evenly. Fuel flows intothe pump/injector high-pressure chamberfree of air bubbles.The injection cam has a steep leading edgeand a gradual slope to the trailing edge.As a result of the steep leading edge, thepump piston is pushed down at highvelocity. A high injection pressure isattained quickly.SSP209/016PumpPistonInjection CamRoller-TypeRocker ArmSSP209/017PumpPistonInjection CamRoller-TypeRocker Arm
  23. 23. 20Pump Injection SystemMixture Formation andCombustion RequirementsGood mixture formation is a vital factor toensure efficient combustion.Accordingly, fuel must be injected in thecorrect quantity at the right time and at highpressure. Even minimal deviations can leadto higher levels of pollutant emissions, noisycombustion, or high fuel consumption.A short firing delay is important for thecombustion sequence of a diesel engine.The firing delay is the period between thestart of fuel injection and the start ofpressure rise in the combustion chamber.If a large fuel quantity is injected during thisperiod, the pressure will rise suddenly andcause loud combustion noise.Pre-injection phaseTo soften the combustion process, a smallamount of fuel is injected at a low pressurebefore the start of the main injection phase.This is the pre-injection phase. Combustionof this small quantity of fuel causes thepressure and temperature in thecombustion chamber to rise.This meets the requirements for quickignition of the main injection quantity, thusreducing the firing delay.The pre-injection phase and the “injectioninterval” between the pre-injection phaseand the main injection phase produce agradual rise in pressure within thecombustion chamber, not a suddenpressure buildup.The effects of this are low combustionnoise levels and lower nitrogenoxide emissions.Main injection phaseThe key requirement for the main injectionphase is the formation of a good mixture.The aim is to burn the fuel completelyif possible.The high injection pressure finely atomizesthe fuel so that the fuel and air can mix wellwith one another.Complete combustion reduces pollutantemissions and ensures high engineefficiency.End of injectionAt the end of the injection process, itis important that the injection pressuredrops quickly and the injector needlecloses quickly.This prevents fuel at a low injectionpressure and with a large droplet diameterfrom entering the combustion chamber.Fuel does not combust completely undersuch conditions, giving rise to higherpollutant emissions.Injection curveThe injection curve of the pump injectionsystem largely matches the enginedemands, with low pressures during thepre-injection phase, followed by an“injection interval,” then a rise in pressureduring the main injection phase. Theinjection cycle ends abruptly.SSP209/101SSP209/100InjectionPressureTimeEngine Demand Pump/Injector
  24. 24. 21Pump Injection SystemInjection CycleHigh-Pressure Chamber FillsDuring the filling phase, the pump pistonmoves upward under the force of thepiston spring and thus increases thevolume of the high-pressure chamber.The pump/injector solenoid valve isnot activated.The solenoid valve needle is in itsresting position.The path is open from the fuel supply lineto the high-pressure chamber.The fuel pressure in the supply linecauses the fuel to flow into thehigh-pressure chamber.SolenoidValve NeedleFuel Supply LineSSP209/024Piston SpringHigh-PressureChamberInjector NeedleFuel Return LinePump/InjectorSolenoid ValvePump PistonInjection CamRoller-TypeRocker Arm
  25. 25. 22Pump Injection SystemPre-Injection Phase StartsThe injection cam pushes the pumppiston down via the roller-type rocker arm.This displaces some of the fuel from thehigh-pressure chamber back into the fuelsupply line.The Diesel Direct Fuel Injection EngineControl Module J248 initiates the injectioncycle by activating the pump/injectorsolenoid valve.The solenoid valve needle is pressed intothe valve seat and closes the path fromthe high-pressure chamber to the fuelsupply line.This initiates a pressure build-up in thehigh-pressure chamber.At 2,611 psi (18,000 kPa / 180 bar), thepressure is greater than the force of theinjector spring.The injector needle is lifted from its seatand the pre-injection cycle starts.SSP209/025Roller-TypeRocker ArmRetraction PistonInjection CamInjector SpringInjector NeedleSolenoidValve NeedlePump/InjectorSolenoid ValveFuel Return LineFuel Supply LineHigh-PressureChamberPiston SpringPump Piston
  26. 26. 23Pump Injection SystemInjector needle dampingDuring the pre-injection phase, the strokeof the injector needle is dampened by ahydraulic cushion. As a result, it is possibleto meter the injection quantity exactly.As soon as the damping piston plunges intothe bore in the injector housing, the fuelabove the injector needle can only bedisplaced into the injector spring chamberthrough a leakage gap.This creates a hydraulic cushion whichlimits the injector needle stroke during thepre-injection phase.FunctionIn the first third of the total stroke, theinjector needle is opened undamped.The pre-injection quantity is injected intothe combustion chamber.SSP209/036DampingPistonHydraulicCushionLeakage GapInjectorHousingInjectorSpringInjectorSpringChamberSSP209/035UndampedStrokeInjectorHousingInjectorSpringInjectorSpringChamber
  27. 27. 24Pump Injection SystemPre-Injection Phase EndsThe pre-injection phase ends immediatelyafter the injector needle opens.The rising pressure causes the retractionpiston to move downward, thus increasingthe volume of the high-pressure chamber.The pressure drops momentarily as aresult, and the injector needle closes.SSP209/026This ends the pre-injection phase.The downward movement of the retractionpiston pre-loads the injector spring to agreater extent.To re-open the injector needle during thesubsequent main injection phase, the fuelpressure must be greater than during thepre-injection phase.Roller-TypeRocker ArmRetraction PistonInjection CamInjector SpringInjector NeedleSolenoidValve NeedlePump/InjectorSolenoid ValveFuel Return LineFuel Supply LineHigh-PressureChamberPiston SpringPump Piston
  28. 28. 25Pump Injection SystemMain Injection Phase StartsThe pressure in the high-pressurechamber rises again shortly after theinjector needle closes.The pump/injector solenoid valveremains closed and the pump pistonmoves downward.At approximately 4,351 psi (30,000 kPa /300 bar), the fuel pressure is greaterthan the force exerted by the pre-loadedinjector spring.The injector needle is again lifted fromits seat and the main injection quantityis injected.The pressure rises to between 27,121 psi(187,000 kPa / 1,870 bar) and 27,846 psi(192,000 kPa / 1,920 bar) because morefuel is displaced in the high-pressurechamber than can escape through thenozzle holes.Maximum fuel pressure is achieved atmaximum engine output. This occurs at ahigh engine speed when a large quantity offuel is being injected.SSP209/027Roller-TypeRocker ArmRetraction PistonInjection CamInjector SpringInjector NeedleSolenoidValve NeedleFuel Supply LineHigh-PressureChamberPiston SpringPump PistonPump/InjectorSolenoid ValveFuel Return Line
  29. 29. 26Pump Injection SystemMain Injection Phase EndsThe injection cycle ends when the DieselDirect Fuel Injection Engine Control ModuleJ248 stops activating the pump/injectorsolenoid valve.The solenoid valve spring opens the solenoidvalve needle, and the fuel displaced by thepump piston can enter the fuel supply line.The pressure drops.The injector needle closes and the injectorspring presses the bypass piston into itsstarting position.This ends the main injection phase.Roller-TypeRocker ArmInjection CamInjector SpringInjector NeedleSolenoidValve NeedlePump/InjectorSolenoid ValveFuel Return LineFuel Supply LinePiston SpringPump PistonSSP209/028Retraction PistonSolenoidValve Needle
  30. 30. 27Pump/Injector Fuel ReturnThe fuel return line in the pump/injector hasthe following functions:• Cool the pump/injector by flushingfuel from the fuel supply line throughthe pump/injector ducts into the fuelreturn line.• Discharge leaking fuel at thepump piston.• Separate vapor bubbles from thepump/injector fuel supply line throughthe restrictors in the fuel return line.Pump Injection SystemSSP209/096Fuel Supply LineLeaking FuelPump PistonRestrictorsFuel Return Line
  31. 31. Engine Management281.9-Liter TDI Engine EDC 16System OverviewSensorsDiesel DirectFuel InjectionEngine ControlModule J24816-PinConnector(DiagnosisConnection)T16ABS Control Modulewith EDL/ASR/ESP J104DrivetrainCAN Data BusBarometricPressureSensor F96Additional Signals• Road Speed Signal• Air Conditioner Compressor Ready• CCS Switch• Three-Phase AC Generator Terminal DFFuel Temperature Sensor G81Brake Light Switch FBrake Pedal Switch F47Clutch Vacuum Vent Valve Switch F36Manifold Absolute Pressure Sensor G71Intake Air Temperature Sensor G72Engine Coolant Temperature Sensor G62Throttle Position Sensor G79Kick Down Switch F8Closed Throttle Position Switch F60Camshaft Position Sensor G40Engine Speed Sensor G28Mass Air Flow Sensor G70
  32. 32. Engine Management29SSP209/053ActuatorsAdditional Signals• Coolant Auxiliary Heater• Engine Speed• Cooling Fan Run-On• Air Conditioner Compressor Cut-Off• Fuel Consumption SignalRelay for Pump, Fuel Cooling J445Pump for Fuel Cooler V166Change-Over Valve for Intake Manifold Flap N239Wastegate Bypass Regulator Valve N75EGR Vacuum Regulator Solenoid Valve N18Glow Plug Indicator Light K29Valve for Pump/Injector, Cylinder 1 N240Valve for Pump/Injector, Cylinder 2 N241Valve for Pump/Injector, Cylinder 3 N242Valve for Pump/Injector, Cylinder 4 N243Glow Plugs Q6Glow Plug Relay J52TransmissionControl ModuleJ217
  33. 33. 30SensorsCamshaft Position Sensor G40The Camshaft Position Sensor G40 is aHall-effect sensor.It is attached to the toothed-belt guardbelow the camshaft gear.It scans seven teeth on the camshaft sensorwheel attached to the camshaft gear.Signal applicationThe Diesel Direct Fuel Injection EngineControl Module J248 uses the signal thatthe Camshaft Position Sensor G40generates to determine the relativepositions of the pistons in the cylinderswhen starting the engine.Effects of signal failureIn the event of Camshaft Position SensorG40 signal failure, the Diesel Direct FuelInjection Engine Control Module J248 usesthe signal that the Engine Speed SensorG28 generates.Electrical circuitG40 Camshaft Position SensorJ248 Diesel Direct Fuel Injection EngineControl ModuleJ317 Power Supply (Terminal 30, B+) RelayEngine ManagementCamshaftSensor WheelSSP209/054Camshaft PositionSensor G40SSP209/055J248G40J317S
  34. 34. Engine Management31Cylinder recognition whenstarting the engineWhen starting the engine, the Diesel DirectFuel Injection Engine Control Module J248must determine which cylinder is in thecompression stroke in order to activate thecorrect pump/injector valve. To achieve this,it evaluates the signal generated by theCamshaft Position Sensor G40, whichscans the teeth of the camshaft sensorwheel to determine the camshaft position.Camshaft sensor wheelSince the camshaft executes one360-degree revolution per working cycle,there is a tooth for each individual cylinderon the sensor wheel. These teeth arespaced 90 degrees apart.To differentiate between cylinders, thesensor wheel has an additional tooth withdifferent spacing for each of cylinders1, 2, and 3.SSP209/094Cylinder 2Cylinder 1Cylinder 3Cylinder 490°
  35. 35. Engine Management32FunctionEach time a tooth passes the CamshaftPosition Sensor G40, a Hall-effect voltageis induced and transmitted to the DieselDirect Fuel Injection Engine ControlModule J248.Because the teeth are spaced at differentdistances apart, the induced voltage occursat different time intervals.From this, the Diesel Direct Fuel InjectionEngine Control Module J248 determinesthe relative positions of the cylinders anduses this information to control thesolenoid valves for pump/injectors.Refer to “Quick-Start Function” (page 34).SSP209/095aSignal Pattern, Camshaft Position Sensor G4090° 90° 90°Cylinder 1 Cylinder 3 Cylinder 4 Cylinder 2 Cylinder 190°
  36. 36. 33Engine ManagementEngine Speed Sensor G28The Engine Speed Sensor G28 is aninductive sensor. It is attached to thecylinder block.SSP209/056J248SSP209/085Engine speed sensor wheelThe Engine Speed Sensor G28 scans a60-2-2 sensor wheel attached to thecrankshaft. This means that the sensorwheel has 56 teeth with two gaps the widthof two teeth each on its circumference.These gaps are 180 degrees apart andserve as reference points for determiningthe crankshaft position.Signal applicationThe signal generated by the Engine SpeedSensor G28 provides both the engine speedand the exact position of the crankshaft.The injection point and the injection quantityare calculated using this information.Effects of signal failureIf the signal of the Engine Speed SensorG28 fails, the engine is switched off.Electrical circuitG28 Engine Speed SensorJ248 Diesel Direct Fuel Injection EngineControl ModuleSSP209/057G28
  37. 37. 34Engine ManagementQuick-Start FunctionTo allow the engine to be started quickly,the Diesel Direct Fuel Injection EngineControl Module J248 evaluates the signalsgenerated by the Camshaft Position SensorG40 and the Engine Speed Sensor G28.The Diesel Direct Fuel Injection EngineControl Module J248 uses the signal thatthe Camshaft Position Sensor G40generates to determine the relativepositions of the pistons in the cylinderswhen starting the engine.Because there are two gaps on thecrankshaft sensor wheel, the Diesel DirectFuel Injection Engine Control Module J248receives a usable reference signal from theEngine Speed Sensor G28 after only half aturn of the crankshaft.Cylinder 1 Cylinder 3 Cylinder 4 Cylinder 2By interpreting the signals from these twosensors, the Diesel Direct Fuel InjectionEngine Control Module J248 determinesthe position of the crankshaft in relation tothe camshaft and thus the positions of thepistons in the cylinders at an early stage.With this information, it can activate thecorrect solenoid valve at the proper time toinitiate the injection cycle in the nextcylinder to reach the compression stage.The quick-start function enables an earlyengine start because synchronization withthe first cylinder is not required.SSP209/095Signal Generatedby Engine SpeedSensor G28SignalGenerated byCamshaft PositionSensor G40One Crankshaft RotationOne Camshaft RevolutionSignal Pattern, Camshaft Position Sensor G40and Engine Speed Sensor G28
  38. 38. 35Engine ManagementFuel Temperature Sensor G81The Fuel Temperature Sensor G81 islocated in the fuel return line between thefuel pump and the fuel cooler. It determinesthe current temperature of the fuel atthat point.The Fuel Temperature Sensor G81 has anegative temperature coefficient. Thesensor resistance decreases withincreasing fuel temperature.Signal applicationThe signal generated by the FuelTemperature Sensor G81 is used bythe Diesel Direct Fuel Injection EngineControl Module J248 to determinethe fuel temperature.This signal is needed to calculate thestart of injection point and the injectionquantity so that allowance can be madefor the density of the fuel at differenttemperatures.This signal is also used to determinethe timing for switching on the fuelcooling pump.Effects of signal failureIn the event of Fuel Temperature SensorG81 signal failure, the Diesel Direct FuelInjection Engine Control Module J248calculates a substitute value from the signalgenerated by Engine Coolant TemperatureSensor G62.Electrical circuitG81 Fuel Temperature SensorJ248 Diesel Direct Fuel Injection EngineControl ModuleSSP209/043SSP209/058G81J248
  39. 39. 36Mass Air Flow Sensor G70The Mass Air Flow Sensor G70 with reverseflow recognition is located in the intake pipe.It determines the intake air mass.The opening and closing actions of thevalve produce reverse flows in the inducedair mass in the intake pipe.The Mass Air Flow Sensor G70recognizes and makes allowance for thereturning air mass in the signal it sendsto the Diesel Direct Fuel Injection EngineControl Module J248.The air mass is accurately measured.Signal applicationThe Diesel Direct Fuel Injection EngineControl Module J248 uses the measuredvalues from the Mass Air Flow Sensor G70to calculate the injection quantity and theexhaust gas recirculation rate.Effects of signal failureIf the signal from the Mass Air Flow SensorG70 fails, the Diesel Direct Fuel InjectionEngine Control Module J248 uses a fixedsubstitute value.Engine ManagementSSP209/044
  40. 40. 37Engine ManagementSSP209/60Engine Coolant Temperature Sensor G62The Engine Coolant Temperature SensorG62 is located at the coolant connection onthe cylinder head. It sends informationabout the current coolant temperature tothe Diesel Direct Fuel Injection EngineControl Module J248.Signal applicationThe Diesel Direct Fuel Injection EngineControl Module J248 uses the coolanttemperature as a correction value forcalculating the injection quantity.Effects of signal failureIf the signal from Engine CoolantTemperature Sensor G62 fails, the DieselDirect Fuel Injection Engine Control ModuleJ248 uses the signal generated by the FuelTemperature Sensor G81 to calculate theinjection quantity.
  41. 41. 38Accelerator Pedal SensorsThe accelerator pedal sensors are integratedinto a single housing and connected to thepedal by mechanical linkage.• Throttle Position Sensor G79• Kick Down Switch F8• Closed Throttle Position Switch F60Signal applicationThe Diesel Direct Fuel Injection EngineControl Module J248 can recognize theposition of the accelerator pedal fromthis signal.In vehicles with an automatic transmission,the Kick Down Switch F8 indicates to theDiesel Direct Fuel Injection Engine ControlModule J248 when the driver wantsto accelerate.Effects of signal failureWithout the signal from Throttle PositionSensor G79, the Diesel Direct Fuel InjectionEngine Control Module J248 is unable torecognize the accelerator pedal position.The engine will only run at an increasedidling speed.Engine ManagementSSP209/059
  42. 42. 39Engine ManagementSSP209/045Intake Manifold SensorsThe intake manifold sensors are integratedinto a single module and installed in theintake pipe.• Manifold Absolute Pressure Sensor G71• Intake Air Temperature Sensor G72Manifold Absolute Pressure Sensor G71Signal applicationThe Manifold Absolute Pressure SensorG71 supplies a signal that is required tocheck the charge pressure (boostpressure).The Diesel Direct Fuel Injection EngineControl Module J248 compares the actualmeasured value with the setpoint from thecharge pressure map.If the actual value deviates from thesetpoint, the Diesel Direct Fuel InjectionEngine Control Module J248 adjusts thecharge pressure via the Wastegate BypassRegulator Valve N75.Effects of signal failureThe charge pressure can no longerbe regulated.Engine performance drops.Intake Air Temperature Sensor G72Signal applicationThe Diesel Direct Fuel Injection EngineControl Module J248 requires the signalgenerated by the Intake Air TemperatureSensor G72 as a correction value forcomputing the charge pressure.It can then make allowance for the effectof temperature on the density of thecharge air.Effects of signal failureIf the Intake Air Temperature Sensor G72signal fails, the Diesel Direct Fuel InjectionEngine Control Module J248 uses afixed substitute value to calculate thecharge pressure.This can result in a drop inengine performance.
  43. 43. 40Engine ManagementBarometric Pressure Sensor F96The Barometric Pressure Sensor F96 islocated inside the Diesel Direct FuelInjection Engine Control Module J248.Signal applicationThe Barometric Pressure Sensor F96sends the current ambient air pressure tothe Diesel Direct Fuel Injection EngineControl Module J248.This value is dependent on the vehicle’sgeographical altitude.With this signal the Diesel Direct FuelInjection Engine Control Module J248can carry out an altitude correction forcharge pressure control and exhaustgas recirculation.Effects of signal failureBlack smoke occurs at altitude.Clutch Vacuum Vent Valve Switch F36The Clutch Vacuum Vent Valve Switch F36is located at the foot controls on vehicleswith manual transmissions.Signal applicationThe Diesel Direct Fuel Injection EngineControl Module J248 determines fromthis signal whether the clutch is engagedor disengaged.When the clutch is engaged, injectionquantity is reduced briefly to preventengine shudder when shifting gears.Effects of signal failureIf the signal from the Clutch Vacuum VentValve Switch F36 fails, engine shudder canoccur when shifting gears.SSP209/061SSP209/062Barometric Pressure Sensor F96
  44. 44. 41Engine ManagementBrake Pedal SensorsThe brake pedal sensors are integratedinto a single module that is mounted on thebrake pedal bracket.• Brake Light Switch F• Brake Pedal Switch F47Signal applicationBoth switches supply the Diesel DirectFuel Injection Engine Control Module J248with the “brake activated” signal.The engine speed is regulated when thebrake is activated for safety reasons,since the Throttle Position Sensor G79could be defective.Effects of signal failureIf one of the two switches fails, DieselDirect Fuel Injection Engine Control ModuleJ248 reduces the fuel quantity.Engine performance drops.SSP209/063
  45. 45. 42Engine ManagementCruise control switchThe signal generated by the cruise controlswitch tells the Diesel Direct Fuel InjectionEngine Control Module J248 that the cruisecontrol system has been activated.Three-phase AC generator terminal DFThe signal supplied by generator terminalDF indicates the load state of the three-phase AC generator to the Diesel DirectFuel Injection Engine Control Module J248.Depending on available capacity, the DieselDirect Fuel Injection Engine Control ModuleJ248 can switch on one, two, or three GlowPlugs (Coolant) Q7 of the coolant auxiliaryheater via the Relay for Preheating Coolant,Low Heat Output J359 and the Relay forPreheating Coolant, High Heat Output J360.CAN data busThe Diesel Direct Fuel Injection EngineControl Module J248, the ABS ControlModule with EDL/ASR/ESP J104, and theTransmission Control Module J217interchange information along aCAN data bus.Additional Input SignalsRoad speed signalThe Diesel Direct Fuel Injection EngineControl Module J248 receives the roadspeed signal from the vehicle speed sensor.This signal is used to calculate variousfunctions, including cooling fan run-onand engine shudder damping whenshifting gears.It is also used to check the cruise controlsystem for proper functioning.Air conditioner compressor readyThe air conditioner switch sends DieselDirect Fuel Injection Engine Control ModuleJ248 a signal indicating that the airconditioner compressor will shortly beswitched on.This enables the Diesel Direct Fuel InjectionEngine Control Module J248 to increasethe engine idle speed before the airconditioner compressor is switched on toprevent a sharp drop in engine speed whenthe compressor starts up.SSP209/083
  46. 46. 43Engine ManagementActuatorsPump/Injector Solenoid ValvesThe 1.9-liter TDI engine with the new pumpinjection system uses four pump/injectorsolenoid valves:• Valve for Pump/Injector, Cylinder 1 N240• Valve for Pump/Injector, Cylinder 2 N241• Valve for Pump/Injector, Cylinder 3 N242• Valve for Pump/Injector, Cylinder 4 N243The pump/injector solenoid valves areattached to their pump/injectors with acap nut.The Diesel Direct Fuel Injection EngineControl Module J248 regulates the start ofinjection points and injection quantities ofthe pump/injectors by activating theirsolenoid valves at the appropriate times.Start of injection pointAs soon as the Diesel Direct Fuel InjectionEngine Control Module J248 activates apump/injector solenoid valve, the magneticcoil presses the solenoid valve needledown into the valve seat and closes off thepath from the fuel supply line to the high-pressure chamber of the pump/injector.The injection cycle then begins.Injection quantityThe injection quantity is determined by thelength of time that the solenoid valve isactivated.Fuel is injected into the combustionchamber as long as the pump/injectorsolenoid valve is closed.SSP209/064
  47. 47. 44Effects of failureIf a pump/injector solenoid valve fails, theengine will not run smoothly andperformance will be reduced.The pump/injector solenoid valve has a dualsafety function.If the valve stays open, pressure cannotbuild up in the pump/injector.If the valve stays closed, the high-pressurechamber of the pump/injector can no longerbe filled.In either case, no fuel is injected intothe cylinders.Electrical circuitJ248 Diesel Direct Fuel Injection EngineControl ModuleN240 Valve for Pump/Injector, Cylinder 1N241 Valve for Pump/Injector, Cylinder 2N242 Valve for Pump/Injector, Cylinder 3N243 Valve for Pump/Injector, Cylinder 4Engine ManagementN240 N241 N242 N243J248SSP209/065
  48. 48. 45Engine ManagementPump/injector solenoid valve monitoringThe Diesel Direct Fuel Injection EngineControl Module J248 monitors the electricalcurrent that actuates the solenoid valves atthe pump/injectors.This provides feedback to the DieselDirect Fuel Injection Engine Control ModuleJ248 of the actual point in time wheninjection begins.The Diesel Direct Fuel Injection EngineControl Module J248 uses this feedback toregulate the beginning of injection periods(BIP) during subsequent combustioncycles and to detect malfunctions of thepump/injector solenoid valves.Start of injection is initiated when thepump/injector solenoid valve is actuated.Actuating current applied to a pump/injectorsolenoid valve creates a magnetic field.As the applied current intensity increases,the valve closes; the magnetic coil pressesthe solenoid valve needle into its valveseat. This closes off the path from thefuel supply line to the pump/injectorhigh-pressure chamber and the injectionperiod begins.As the solenoid valve needle contacts itsvalve seat, the distinctive signature of analternately dropping and rising current flowis detected by the Diesel Direct FuelInjection Engine Control Module J248. Thispoint is called the beginning of injectionperiod (BIP). It indicates the completeclosure of the pump/injector solenoid valveand the starting point of fuel delivery.“Start of injection” is the pointin time when the actuatingcurrent to the pump/injectorsolenoid valve is initiated.”Beginning of injectionperiod (BIP)” is the point in timewhen the solenoid valve needlecontacts the valve seat.With the solenoid valve closed, a holdingcurrent is maintained at a constant level bythe Diesel Direct Fuel Injection EngineControl Module J248 to keep it closed. Oncethe required time period for fuel delivery haselapsed, the actuating current is switchedoff and the solenoid valve opens.SSP209/097Current Pattern - Pump/Injector Solenoid ValveBeginning ofInjection Period(BIP) (ValveCloses)TimeSolenoidValveActuatingCurrentIntensityEnd ofValveActuationStart ofValveActuation(Start ofInjection)PickupCurrentControlLimitHoldingCurrent
  49. 49. 46Engine ManagementThe actual moment at which the pump/injector solenoid valve closes (BIP) is usedby the Diesel Direct Fuel Injection EngineControl Module J248 to calculate the pointof actuation for the next injection period.If the actual BIP deviates from the mappeddetails stored in the Diesel Direct FuelInjection Engine Control Module J248, it willcorrect the point of valve actuation (start ofinjection) for the next combustion cycle.To detect pump/injector solenoid valvefaults, the Diesel Direct Fuel InjectionEngine Control Module J248 evaluates theBIP position from the current flow pattern.If there are no faults, BIP will be within thecontrol limit. If this is not the case, thevalve is faulty.Effects of failureIf a fault is detected at the solenoid valve,start of injection is determined based onfixed values from the control map.Regulation is no longer possible andperformance is impaired.ExampleIf there is air inside the pump/injector, thesolenoid valve needle has a low resistancewhen it closes. The valve closes quicklyand the BIP is earlier than expected.In this case, the self-diagnosis indicates thefollowing fault message:“BIP below control limit”
  50. 50. 47Engine ManagementChange-Over Valve forIntake Manifold Flap N239The Change-Over Valve for IntakeManifold Flap N239 is located in theengine compartment, in the vicinity ofthe Mass Air Flow Sensor G70.It switches the vacuum for actuating theintake manifold flap in the intake pipe.This stops the engine shuddering whenthe ignition is turned off.Diesel engines have a highcompression ratio.The engine shudders when the ignition isturned off because of the high compressionpressure of the induced air.The intake manifold flap interrupts the airsupply when the engine is turned off. Littleair is compressed and the engine runssoftly to a halt.FunctionIf the engine is turned off, the Diesel DirectFuel Injection Engine Control Module J248sends a signal to the Change-Over Valve forIntake Manifold Flap N239, which thenswitches the vacuum for the vacuum motor.The vacuum motor closes the intakemanifold flap.2SSP09/068SSP209/0690 I
  51. 51. 48Engine ManagementEffects of failureIf the Change-Over Valve for IntakeManifold Flap N239 fails, the intakemanifold flap stays open.The tendency of the engine to shudderwhen switched off will increase.Electrical circuitJ217 Transmission Control ModuleJ248 Diesel Direct Fuel Injection EngineControl ModuleN239 Change-Over Valve for IntakeManifold FlapS FuseSJ317N239J248SSP209/070
  52. 52. 49Engine ManagementRelay for Pump, Fuel Cooling J445The Relay for Pump, Fuel Cooling J445 islocated on the engine control modulemounting bracket.It is activated by the Diesel Direct FuelInjection Engine Control Module J248 at afuel temperature of 158°F (70°C) andswitches the working current for the Pumpfor Fuel Cooler V166.Effects of failureIf the Relay for Pump, Fuel Cooling J445fails, the heated fuel flowing back fromthe pump/injectors to the fuel tank will notbe cooled.The fuel tank and the Sender forFuel Gage G can be damaged.Electrical circuitJ248 Diesel Direct Fuel InjectionEngine Control ModuleJ317 Power Supply (Terminal 30, B+) RelayJ445 Relay for Pump, Fuel CoolingS FuseV166 Pump for Fuel CoolerThe Output Check Diagnosisfunction in the self-diagnosis canbe used to check whether theRelay for Pump, Fuel CoolingJ445 has been activated by theDiesel Direct Fuel InjectionEngine Control Module J248.SSP209/071SSP209/072A/+SSJ445J248J317V166M
  53. 53. 50Engine ManagementWastegate Bypass Regulator Valve N75The engine has a variable turbine geometryfor optimally adapting the charge pressureto the actual driving conditions.To regulate the charge pressure, thevacuum in the vacuum unit for turbochargervane adjustment is set depending on thepulse duty factor.The Wastegate Bypass Regulator ValveN75 is activated by the Diesel Direct FuelInjection Engine Control Module J248.Effects of failureIf the Wastegate Bypass Regulator ValveN75 fails, the vacuum unit reverts toatmospheric pressure.As a result, charge pressure is lower andengine performance is impaired.SSP209/075
  54. 54. 51Engine ManagementSSP209/075EGR Vacuum RegulatorSolenoid Valve N18The EGR Vacuum Regulator SolenoidValve N18 enables the exhaust gasrecirculation system to mix a portion ofthe exhaust gases with the fresh airsupplied to the engine.This lowers the combustion temperatureand reduces the formation of oxides ofnitrogen.To control the quantity of exhaust gasesreturned for combustion, the Diesel DirectFuel Injection Engine Control Module J248activates the EGR Vacuum RegulatorSolenoid Valve N18 with duty cycles basedon internal control maps.Effects of failureEngine performance is lower and exhaustgas recirculation is not assured.Glow Plug Indicator Light K29The Glow Plug Indicator Light K29 islocated in the instrument cluster.It has the following tasks:• It signals to the driver that the pre-starting glow phase is in progress. In thiscase, it is lit continuously.• If a component with self-diagnosticcapability becomes faulty, the warninglamp flashes.Effects of failureThe Glow Plug Indicator Light K29 comeson and does not flash.A fault message is stored to thefault memory.SSP209/077
  55. 55. 52Additional Output SignalsEngine ManagementEngine speedThis signal provides information onengine speed for the tachometer in theinstrument cluster.Cooling fan run-onThe run-on period of the cooling fan iscontrolled according to a characteristiccurve stored in the Diesel Direct FuelInjection Engine Control Module J248.It is calculated from the current coolanttemperature and the load state of theengine during the previous driving cycle.The Diesel Direct Fuel Injection EngineControl Module J248 uses this signal toactivate the cooling fan relay.Air conditioner compressor cut-offTo reduce engine load, the Diesel DirectFuel Injection Engine Control Module J248switches the air conditioner compressor offunder the following conditions:• After every starting cycle (forapproximately six seconds).• During rapid acceleration from lowengine speeds.• At coolant temperatures in excess of248°F (120°C).• In the emergency running program.Fuel consumption signalThis signal provides information on fuelconsumption for the multifunctional displayin the instrument cluster.Coolant auxiliary heaterThanks to its high efficiency, the 1.9-literTDI engine with pump injection systemdevelops so little heat that sufficient heatoutput may not be available incertain circumstances.In countries with cold climates, an electricalauxiliary heater is used to heat the coolantat low temperatures.The coolant auxiliary heater is comprised ofthree Glow Plugs (Coolant) Q7. They areinstalled to the coolant connection on thecylinder head.The Diesel Direct Fuel Injection EngineControl Module J248 uses the coolantauxiliary heater signal to activate the relaysfor low and high heat output.Either one, two, or all three Glow Plugs(Coolant) Q7 are switched on depending onthe available capacity of the three-phaseAC generator.SSP209/084
  56. 56. 53Glow Plug SystemGlow Plug SystemThe glow plug system makes it easierto start the engine at low outsidetemperatures. It is activated by theDiesel Direct Fuel Injection Engine ControlModule J248 at coolant temperaturesbelow 48°F (9°C).The Glow Plug Relay J52 is activated by theDiesel Direct Fuel Injection Engine ControlModule J248. The Glow Plug Relay J52then switches on the working current forthe Glow Plugs Q6.FunctionThe glow process is divided into twophases, the glow period and the extendedglow period.Glow PeriodThe glow plugs are activated when theignition is switched on and outsidetemperature is below 48°F (9°C). The GlowPlug Indicator Light K29 will light up.Once the glow plug period has elapsed, theGlow Plug Indicator Light K29 will go outand the engine can be started.Extended Glow PeriodThe extended glow period takes placewhenever the engine is started, regardlessof whether or not it is preceded by a glowperiod.This reduces combustion noise, improvesidling quality and reduces hydrocarbonemission.The extended glow phase lasts no morethan four minutes and is interrupted whenthe engine speed rises above 2500 rpm.Glow Plug System OverviewSSP209/099Engine CoolantTemperatureSensor G62Glow PlugIndicatorLight K29Glow PlugRelay J52Glow Plugs Q6Diesel Direct Fuel InjectionEngine Control Module J248Engine SpeedSensor G28
  57. 57. 54Functional DiagramEDC 16 Functional Diagramfor 1.9-Liter TDI EngineComponentsE45 Cruise Control SwitchF Brake Light SwitchF8 Kick Down SwitchF36 Clutch Vacuum Vent Valve SwitchF47 Brake Pedal SwitchF60 Closed Throttle Position SwitchG28 Engine Speed SensorG40 Camshaft Position SensorG62 Engine Coolant Temperature SensorG70 Mass Air Flow SensorG71 Manifold Absolute Pressure SensorG72 Intake Air Temperature SensorG79 Throttle Position SensorG81 Fuel Temperature SensorJ52 Glow Plug RelayJ248 Diesel Direct Fuel Injection EngineControl ModuleJ317 Power Supply (Terminal 30, B+) RelayJ359 Relay for Preheating Coolant, LowHeat OutputJ360 Relay for Preheating Coolant, HighHeat OutputJ445 Relay for Pump, Fuel CoolingN18 EGR Vacuum Regulator Solenoid ValveN75 Wastegate Bypass Regulator ValveN239 Change-Over Valve for Intake Manifold FlapN240 Valve for Pump/Injector, Cylinder 1N241 Valve for Pump/Injector, Cylinder 2N242 Valve for Pump/Injector, Cylinder 3N243 Valve for Pump/Injector, Cylinder 4Q6 Glow Plugs (Engine)Q7 Glow Plugs (Coolant)S FuseV166 Pump for Fuel CoolerAdditional SignalsA Brake LightsB Fuel Consumption SignalC Engine Speed SignalD Air Conditioner Compressor Cut-OffE Air Conditioner Compressor ReadinessF Road Speed SignalG Cruise Control Switch Voltage SupplyH Cooling Fan Run-OnK Diagnosis and Immobilizer WireL Glow Period ControlM Drivetrain CAN Data Bus (Low)N Drivetrain CAN Data Bus (High)O Three-Phase AC Generator Terminal DFColor CodingInput SignalOutput SignalPositiveGroundCAN Data BusBi-directional
  58. 58. 55Functional DiagramSSP209/080301531 3131B D GJ 317S S S SN239 N75 N18Q7 Q7J360A/+G70F60/F8 G79G28G81F F47E45G62F36J52A/+Q6G72CSG71SSSN240 N241 N242 N243SG40EFV166J445J359Ain outJ248HKLMNOM
  59. 59. 56ServiceSelf-DiagnosisThe following functions can be read outusing the Vehicle Diagnosis, Test andInformation System VAS 5051:01 Interrogate control unit version02 Interrogate fault memory03 Actuator diagnosis04 Basic adjustment05 Erase fault memory06 End of output07 Encode control unit08 Read measured value blockFunction 02 – Interrogate fault memoryThe color coded components arestored to the fault memory by theself-diagnosis function.SSP209/082SSP209/081N240, N241,N242, N244F96J248J104V166Q6J445N75N239N18K29J217G81G62G79F8F60G40G28G70 J52G71G72FF47
  60. 60. 57ServicePump/Injector AdjustmentAfter installing a pump/injector, theminimum clearance between the base ofthe high-pressure chamber and the pumppiston must be adjusted at the pump/injector adjusting screw.This adjustment prevents the pump pistonfrom knocking against the base of the high-pressure chamber due to heat expansion.For a complete description ofthis adjustment procedure,refer to the Repair Manual.SSP209/098High-PressureChamberMinimumClearancePump PistonBall PinAdjusting ScrewInjection CamRoller-TypeRocker Arm
  61. 61. 58ServiceSpecial ToolsMarking PlateT 10008Holds the hydraulic toothed belt tensionerin place when installing and removing thetoothed belt.Crankshaft Sealing RingAssembly FixtureT 10053Guide sleeve and compression sleeve forinstalling the crankshaft sealing ring.Camshaft Gear PullerT 10052Camshaft gear removal from the taperedend of the camshaft.Camshaft Gear Counter-HolderT 10051Camshaft gear installation.Crankshaft StopT 10050Holds the crankshaft in place atthe crankshaft gear when adjustingthe port timing.SSP209/090aSSP209/090bSSP209/090cSSP209/090dSSP209/090e
  62. 62. 59ServiceSocket InsertT 10054Pump/injector clamping block fastenerinstallation.Pressure GaugeVAS 5187Fuel pressure measurement at the supplyline to the fuel pump.ShackleT 10059This shackle is used to remove and installthe engine in the Passat. The engine ismoved into position using this shackle incombination with lifting gear 2024A.Pump/Injector PullerT 10055Pump/injector removal from thecylinder head.Pump/Injector O-Ring Assembly SleevesT 10056O-ring installation on the pump/injectors.SSP209/090fSSP209/090gSSP209/090hSSP209/090kSSP209/090i
  63. 63. 60Notes
  64. 64. 61Knowledge AssessmentAn on-line Knowledge Assessment (exam) is available for this Self-Study Program.The Knowledge Assessment may or may not be required for Certification.You can find this Knowledge Assessment at:www.vwwebsource.comFrom the vwwebsource.com Homepage, do the following:– Click on the Certification tab– Type the course number in the Search box– Click “Go!” and wait until the screen refreshes– Click “Start” to begin the AssessmentFor Assistance, please call:Certification Program Headquarters1 – 877 – CU4 – CERT(1 – 877 – 284 – 2378)(8:00 a.m. to 8:00 p.m. EST)Or, E-Mail:Comments@VWCertification.com
  65. 65. Volkswagen of America, Inc.3800 Hamlin RoadAuburn Hills, MI 48326Printed in U.S.A.October 2003