Service TrainingAUDI A6 ‘05 AssembliesSelf-Study Programme 325Engine/gearbox combinations0A309L3,0 l-V6-TDI01J01X/02X3,2 l-V6-FSI09L4,2 l-V501J01X/02X2,4 lContents3,0 l-V6-TDI-Motor mit Common-Rail-Einspritzung3.0 l V6Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Technical data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Mechanics – Crankcase/Crank drive/Oil pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Cylinder head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Chain drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Air intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 VTG turbocharger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Exhaust gas recirculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Exhaust system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Oxygen sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Pre-heating system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Fuel supply – 3rd generation common rail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Piezo injector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Particle filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Engine management/System overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Function diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283.2 l V6 FSI engineIntroduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Technical data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Mechanics – Crankcase and crankshaft assembly . . . . . . . . . . . . . . . . . . . . . . . . 32 Engine ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Oil supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Engine control – Chain drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Cylinder head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Camshaft adjusters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Intake system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Exhaust system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Fuel supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 FSI operating methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Engine management/System overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Function diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Special tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50The Self-Study Programme provides information on the fundamentals of design and function of new vehicle models, new vehicle components or new technologies. The Self-Study Programme is not a Workshop Manual! Specified values serve only to make the information easier to understand and relate to the software version that was valid at the time the Self-Study Programme (SSP) was created. For maintenance and repair work, please make sure to use the current technical documentation.ReferenceNoteGearbox – manual transmissionIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Technical data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Brief description of 0A3 gearbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Brief description of the 01X/02X gearbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 01X/02X bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 0A3 bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 01X/02X lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 0A3 lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Inner gearshift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 0A3 synchronisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 01X and 02X synchronisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Gear selector (outer gearshift) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68Gearbox – automatic transmissionIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Gear selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Selector lever locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Emergency release. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Selector lever positioning/Display unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 Ignition key anti-removal lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Steering wheel Tiptronic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 6-gear automatic transmission 09L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 6-gear automatic gearbox 09L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Technical data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Converter clutch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Oil management and lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Function diagram for 09L gearbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Transmission ratio/Hydraulics (lubrication) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 Dynamic switching programme – DSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Electro-hydraulic control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Multitronic 01J . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Combination with the 3.2 l V6 FSI engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 New features – measures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Vane-type pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Tiptronic /Dynamic Regulating Programme DRP . . . . . . . . . . . . . . . . . . . . . . . . . 89 Hill starts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Function diagram for 01J multitronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 903.0 l V6 TDI engine with common-rail injectionIntroductionWith the 3.0 l V6 TDI engine with common rail, Audi has introduced the fourth engine in the new generation of V engines. Its dimensions and its total weight of approx. 220 kg make it one of the lightest and most compact V6 diesel engines around.325_0016The engine code and the engine number are located at the front right of the cylinder block, next to the vibration damper.BMK 338325_013Torque performance curve500200Torque in Nm Power in kWNmkW30012020080100400 1000 2000 3000 4000 5000Engine speed in rpmTechnical dataCode Type Displacement in cm3 Power in kW (hp) Torque in Nm Bore in mm Stroke in mm Compression Weight in kg Firing order Emission controlBMK V engine with an angle of 90° 2967 165 (224) at 4,000 rpm 450 at 1,400 to 3,250 rpm 83.0 91.4 17.0 : 1 Approx. 221 1-4-3-6-2-5 With catalytic converter, oxygen sensor, cooled exhaust gas recirculation (particle filter optional) EDC 16 CP, (common rail) EU IVEngine management Exhaust standard73.0 l V6 TDI engine with common-rail injectionMechanicsCrankcase The engine block is made of GGV-40 (vermicular graphite cast iron) with a cylinder gap of 90 mm (previously 88 mm). The cylinder bores undergo UV-photon honing for friction optimisation and in order to minimise initial oil consumption. (Note on page 7)325_005Crank drive The crankshaft, which is forged from temper-hardened steel, is mounted in four places in a main bearing frame. Industrially cracked trapezoid con-rods are screwed to the crankshaft using a sputtered bearing at the top and a 3-material bearing at the bottom.325_030Piston A cast piston without valve pockets and with a centrally arranged piston trough is cooled with injection oil via a ring channel (as for 3.3 l V8 CR).325_0328Oil pump The tried-and-trusted Duocentric oil pump is used for the new generation of V6 engines. It is driven by the chain drive via a hexagon shaft.UV photon honing This involves using a laser beam to smooth the cylinder bores following honing. The laser beam, which is applied at high force, melts down the remaining metal nibs in the one-billionth range. A smooth cylinder bore is achieved immediately in this way rather than through the working of the piston.325_027Retaining frame A sturdy retaining frame made of GGG 60 forms the main bearing assembly and serves to reinforce the crankcase.Bolts/ main bearing assembly 325_010Top section of oil pan The division between the crankcase and the oil pan is at the middle of the crankshaft. The two-section oil pan is made up of an aluminium pressure-cast top section and a bottom section made of steel plate.325_01193.0 l V6 TDI engine with common-rail injectionCylinder head Four valves per cylinder ensure optimum charging of the combustion chamber. In the new V6 TDI, the valves are actuated by roller-type cam followers with hydraulic valve clearance compensation. The acoustics of the unit benefits from the use of the roller-type cam followers. These, together with the tensioned and practically play-free camshaft drive pinions, reduce the mechanical noise of the valve gear.Cylinder head coverCylinder head cover sealRetaining frameCamshaftCamshaftThe two sturdy camshafts are manufactured from a precision steel tube, cam rings and the two steel plugs using the IHU procedure*. The exhaust camshafts are driven by the inlet camshafts via spur gears. The spur gears are straight-toothed (previously the spur gears had bevelled teeth).Valve gearCylinder head* IHU – internal high-pressure recasting325_03410Tooth profile clearance compensation The spur gear of the exhaust camshaft (driven spur gear) comes in two parts. The wide spur gear is held on the camshaft through spring actuation and has three ramps at the front. The narrow spur gear has the corresponding grooves and is capable of both radial and axial movement.Spur gearsBelleville spring washer325_038 325_039Note: Please see assembly instructions in Workshop Manual.A defined axial force is produced via a Belleville spring washer, where the axial movement is converted at the same time into a rotary movement with the help of the ramps. This offsets the teeth of the two driven spur gears, which in turn affects tooth clearance compensation.Installation positionClearance compensation325_065325_066113.0 l V6 TDI engine with common-rail injectionChain drive The new drive generation of V engines is implemented via chain drives and thus replaces the toothed belt. This has made it possible to use a shorter engine type for a wider range of possible applications in various models. The chain drive is designed as a simplex bush chain (single chain) and is fitted at the gearbox side. It is made up of a central chain (drive A) running from the crankshaft to the intermediate sprockets and a chain to the inlet-side camshaft of both the left and right cylinder heads (drive B + C). And on a second level, from the crankshaft to the oil pump drive and the balancer shaft (drive D). A separate hydraulic, spring-supported chain tensioner with the required chain guides is fitted for each chain drive. Advantage: Maintenance-free and designed for the service life of the engine.Balancer shaft The new feature here is that the balancer shaft is accommodated in the inner V of the engine block, where the shaft goes through the engine and the balancing weights are secured at the ends. Driven by chain drive D, the balancer shaft turns at crankshaft speed against the direction of rotation of the engine.Balancer shaft driveBalance weights 325_076Camshaft drive – drive B Bank 1 Central chain drive – drive ACamshaft drive – drive C Bank 2Balancer shaft drive325_033Oil pump drive Second chain drive – drive DCrankshaft drive12Air intakeIntake manifold with butterfly valves Butterfly valves that can be regulated smoothly are integrated into the intake tract. These can be used to adapt the air movement according to the current engine speed and load with regard to emissions, consumption and torque/power. The butterfly valve adjuster with potentiometer reports the current position of the butterfly valve back to the engine control unit.Exhaust gas recirculation unit Exhaust gas recirculation flow Intake pipeThrottle position adjusterIntake air325_031 Butterfly valves Electric butterfly valve adjusterExhaust gas recirculation: This involves high-pressure exhaust gas recirculation. The entry of exhaust gasses into the intake tract counters the intake air flow. This results in a constant mixture of fresh air and exhaust gas.Throttle position adjuster: The throttle is closed in order to stop the engine. This reduces the compression effect and achieves softer engine coasting. In addition, the exhaust gas recirculation rate can be increased through targeted, map-controlled closure.Note: The throttle and butterfly valves are opened in coasting mode in order to check the air flow sensor and balance the oxygen sensor.133.0 l V6 TDI engine with common-rail injectionIntake manifold with electric adjuster for controlling the butterfly valvesButterfly valve closedButterfly valve openTangential pipeSwirl duct325_047325_048To optimise the torque and combustion, a closed swirl duct increases the swirl at low loads. When the engine is started, the butterfly valves are open and are only closed again at idle speed (duty cycle: approx. 80 %). Continuous opening is performed from idle speed to approx. 2,750 rpm (duty cycle: approx. 20 %).To optimise performance and combustion, an open swirl duct allows a high level of cylinder charging at high loads. The butterfly valves are always completely open at a speed of approx. 2,750 rpm or higher. The butterfly valve is also open both at idle speed and during coasting.Note: When the adjuster is replaced, it must be adapted to suit the butterfly valves. The valve body must also be replaced when the adjuster is replaced from another engine.14VTG turbocharger, electrically adjustable To guarantee a fast response from the turbocharger at low speeds, air guide vane adjustment has been implemented using an electric adjuster. This allows the exact positioning of the air guide vane to achieve optimum boost pressure. Note: In addition, a temperature sensor is integrated in front of the turbine in the turbine housing. This measures the boost air temperature and prevents the turbocharger from overheating by activating engine management. This is also used to initiate the regeneration of the particle filter if the measured temperature is 450 °C or higher. The connection for exhaust gas recirculation is located in the downpipe, which joins the two cylinder banks on the exhaust side. This involves high-pressure exhaust gas recirculation. This means that the exhaust gas recirculation pressure is always higher than the intake pipe pressure. Turbocharger adjustment is performed in a controlled way at: – a low load and low speed in order to build up the boost pressure quickly. Regulated at: – a high load and high speed in order to maintain the boost pressure at the optimum range.Temperature sensorElectric adjusterAir guide vane adjustment325_026Exhaust gas recirculation To achieve a high exhaust gas recirculation flow, a vacuum-controlled exhaust gas recirculation valve is installed. This controls the quantity of exhaust gas recirculated in the intake tract. To effectively reduce the particle and nitric oxide (NOx) emissions, the exhaust gasses are cooled by a switchable, water-filled exhaust gas recirculation cooler when the engine is warm.325_035153.0 l V6 TDI engine with common-rail injectionCold engine: By-pass flap open Exhaust gas recirculation is performed immediately so as to heat up the catalytic converter as quickly as possible.325_037Warm engine: By-pass flap closed Exhaust gas recirculation must be performed using the water-cooled exhaust gas recirculation cooler.325_036Exhaust system The exhaust manifolds are designed as an air gap-insulated sheet metal manifold. They are installed in the inner V of the engine on the exhaust turbocharger.Exhaust gas recirculationOxygen sensorCatalytic converterTemperature sensorTemperature sensorDifferential pressure sensorManifold, air gap-insulated325_025 Particle filter16Oxygen sensing An oxygen sensor is used for the first time in an Audi diesel engine. This is the broadband oxygen sensor, which you may already know from the petrol engine. An important feature of this oxygen sensor is that it can record the oxygen signal over the entire engine speed range. The oxygen sensor regulates the exhaust gas recirculation quantity and corrects smoke emissions. Oxygen sensing (approx. 1.3 or less) can help to adjust the exhaust gas recirculation rate to the smoke limit, thereby producing higher exhaust gas recirculation rates. The engine works with excess air. Oxygen sensing is also used for mass air flow sensor plausibility (HFM). The mass air flow is calculated from the oxygen value using a calculation model and compared to the value from the mass air flow sensor. Adjustments can thus be made over the whole system (exhaust gas recirculation, injection, fuel delivery).Note: If the oxygen signal fails, a fault is entered and the malfunction indicator light (MIL) comes on.Sensor element325_103Pre-heating system Here, the pre-heating system known as the diesel quick-start system is used with new ceramic glow plugs. They reach a temperature of 1,000 °C in two seconds and thus guarantee a petrol-engine quick-start without the "minute’s silence" for diesel. The voltage is reduced step-by-step in the following activating intervals and is significantly less than the available vehicle voltage. To relieve the vehicle voltage, the glow plugs are activated with pulse width modulation (PWM) and phase offset.Spark plug housing Graphite bushing Glow pin Insulating washer ConnectorSealing ring325_100 Graphite tablet Connection Tensioning pin sleeve, top Tensioning Metal ring sleeve, bottomContactVoltage profile Phase 1: Phase 2: Phase 3: approx. 9.8 V – fast heating 6.8 V 5V Temperature curve Power curve Voltage curve750 0 5 10 15 20Temperature °C10503095020850 -1-2-325 30 35 40100Time SNote: Please observe the precautionary measures described in the Workshop Manual when working with ceramic glow plugs. Caution, very easily damaged!17Current A, Voltage V3.0 l V6 TDI engine with common-rail injectionFuel supply – 3rd generation common rail A 3rd generation common-rail system from Bosch controls the fuel/air mixture. It has a high-pressure pump, driven by a toothed belt and one distributor plate (rail) for each cylinder bank.300 - 1,600 barMax. 1.8 bar permittedMax. 1.6 bar permittedMechanical fuel pumpValve for fuel metering N290 (fuel trim unit)High-pressure pump CP3.2+ 10-bar pressure-holding valve G410 Permeability in opposite direction at 0.3 - 0.5 bar for charging the injectors following repairs.Temperature sensor G81Bi-metallic pre-heating valve High pressure of 300 - 1,600 barReturn pressure from injector: 10 barFlow-side pressure: max. 1.6 bar Return-side pressure: max. 1.8 bar Fuel filter with water separator18The injection pressure has been increased to 1,600 bar, which is 250 bar more than in earlier 2nd generation common-rail systems.Pressure sensor G247Rail element in cylinder bank II 4 5 6RestrictorRail element in cylinder bank I 1 2 3Pressure control valve N7510 barPiezo injector 1 … 3 N30/31/32 Mechanical crash valveFuel cooler (air) on vehicle underbodyBaffle housingTank Fuel pump (pre-feed pump) G6325_003193.0 l V6 TDI engine with common-rail injectionHigh-pressure fuel circuit The Piezo injectors are the most important new feature of the new common-rail system. Fuel injection involves the Piezo effect.Pressure-regulating valve N276 Rail element in cylinder bank I N33 - 84Distributor between the railsRail element in cylinder bank IIRail pressure sensor G247High-pressure pump 325_002Note: The design and function of the high-pressure pump are described in the SSP 227.Piezo injectors N30-32Gear pump The gear pump, which is driven via the continuous eccentric shaft of the high-pressure pump by a toothed belt, feeds the fuel from the tank to the high-pressure pump using the inner tank pump.325_04920High-pressure pump A dual-regulator system is used to regulate the fuel pressure. The fuel pressure is regulated in the near-idle speed range, when the engine is cold and to reduce the engine torque using the fuel pressure regulator N276 on the rail. At full-power and when the engine is hot, the fuel is routed to the pressure-regulating system via the fuel pressure regulator (fuel trim unit) N290 to prevent the fuel from heating up unnecessarily. The engine control unit initiates injection release when the fuel pressure is 200 bar or higher in the rail. The engine control unit disables fuel injection as soon as the fuel pressure in the rail falls below 130 bar.High-pressure piston 325_078 Gearwheel fuel pump High-pressure connection Fuel trim unit N290 Fuel feed from tank Eccentric shaftInlet valvePiezo injectorNote: Whenever an injector is replaced, it must be adapted to suit the injection system and an injector quantity comparison (IQC) must be performed. Please follow the relevant troubleshooting steps to do this.O ring Moulded connectorElectric connection (flat connector) Bar filterBodyReturn connection O ring Actuator foot Actuator Actuator module Actuator sleeve Adjusting shim Actuator head Diaphragm Adjusting piece Low-pressure sealing ring Coupler body Coupler piston Valve piston Tube spring Valve piston spring Nozzle body Spring retainer Nozzle module Coupler moduleValve plate Valve pin Pilot valve Valve spring Restrictor plate Nozzle tension nutNozzle spring Sealing washer Adjusting shim Nozzle needle 325_015213.0 l V6 TDI engine with common-rail injectionInjector function The Piezo effect is used for controlling the injector. The use of the Piezo element means that: – more electrical activation periods per stroke – very short switching times for several injections – huge force against the current rail pressure – high lift accuracy for fast drop-off of the fuel pressure – activation voltage of 110 - 148 volts, depending on the rail pressure can be achieved. 264 Piezo layers are installed in the actuator.Actuator module Piezo layersPiezo effect If you deform a crystal made up of ions (turmalin, quartz, Seignette salt), an electric potential is produced. The Piezo-electric effect can be reversed by applying a certain voltage. This makes the crystal longer. Caution, high voltage! Please read safety notes in Workshop Manual.Coupler piston325_016A hydraulic converter (coupler module) converts the increase in length of the actuator module into hydraulic pressure and motion, which affect the pilot valve. The coupler module works like a hydraulic cylinder. It is continuously thrown into reverse movement with a fuel pressure of 10 bar by a pressure-regulating valve. The fuel serves as the pressure pad between coupler piston "A" and valve piston "B" in the coupler module. When an injector is closed (air in the system), the injector is bled by starting at starter speed. In addition, the injector is filled against the fuel flow direction with the help of the inner tank pump via the pressure-holding valve.Coupler piston "A" Coupler modulePressure padNote: If this pressure is not present in the reverse stroke, the injector function is disabled.325_017 Valve piston "B"22Coupler elementThe pilot valve consists of a valve plate, valve pin, valve spring and a restrictor plate. The fuel flows at current rail pressure through the feed restrictor (Z) in the restrictor plate to the nozzle needle and into the space above the nozzle needle. This produces pressure compensation above and below the nozzle needle. The nozzle needle is kept closed mainly by the spring force of the nozzle spring.Valve pinPilot valveDrain restrictor (A)Feed restrictor (Z)AWhen the valve pin is pressed, the return opens and the rail pressure flows off first through a larger drain restrictor (A) above the nozzle needle. The rail pressure lifts the nozzle needle from its seat, thereby causing injection. The fast switching pulses of the Piezo element result in several injections per stroke one after the other.ZRestrictor plate Nozzle needle Nozzle spring325_018Pre- and post-injections Two pre-injections are performed when the engine is cold and in the near-idle speed range. As the load increases, the pre-injections aregradually retarded until only the main injection is used at full power. The two post-injections are needed in order to regenerate the particle filter.Restrictor bore for returnCoupler elementInflow with rail pressureValve pinRestrictor plateNozzle springNozzle closedNozzle open325_028325_029Note: The pre-injections depend on the load, the speed and the engaged gear (acoustics).High pressureLow pressure233.0 l V6 TDI engine with common-rail injectionParticle filter A particle filter without a catalytic-effect additive is used in the 3.0 l V6 CR diesel engine. The so-called "Catalysed Soot Filter" (CSF) has a filter coating containing precious metal. Several sensors are needed in order to initiate the regeneration of the filter and system monitoring. Three temperature sensors are installed – one in front of the turbocharger, one behind the catalytic converter and one in front of the particle filter. A differential pressure sensor monitors the pressure difference before and after the filter. The accumulation of soot on the filter is detected here. During passive regeneration without engine management intervention, the soot stored in the particle filter is converted slowly and carefully into CO2. This happens at temperatures of between 350 °C and 500 °C, primarily when travelling on motorways, due to the low exhaust gas temperature during short journeys or city travel. For frequent city travel, an active regeneration must be performed via engine management every 1,000 - 1,200 km.Exhaust gas recirculationOxygen sensorCatalytic converterTemperature sensor G235 Differential pressure sensor G450Temperature sensor G448CO –Carbon monoxide Coated particle filter 325_020HC–HydrocarbonC–SootCO2 –Carbon dioxideNOx –Nitric oxideH2O –WaterO2–Oxygen24The filter element is like a conventional catalytic converter, the only difference being that the pipes are closed off alternately in inlet and outlet direction. This means that the soot-laden exhaust gasses must penetrate the gas-permeable silicon carbide walls. The gas therefore flows to the exhaust system outlet, while the soot stays on the ceramic wall. This is coated with a mixture of platinum and ceroxide.The platinum coating of the filter element produces nitrogen dioxide NO2, which causes soot oxidation above a temperature of 350 °C (passive regeneration). The ceroxide component of the coating accelerates the fast thermal regeneration with oxygen (O2) above 580 °C (active regeneration).Differential pressure sensorPurified exhaust gas without sootPre-purified exhaust gas with soot325_021Temperature sensorPurified exhaust gas without sootCOCH2OHCCO2O2NOx 325_022Particle separationPre-purified exhaust gas with sootRegeneration is performed, as required, using a pre-programmed simulation model in the engine control unit, which determines the filter loading from the user’s driving profile and the value indicated by the differential pressure sensor. For this purpose, the temperature on the turbocharger is regulated to approx 450 °C by performing a post-injection close to the main injection, by increasing the injection quantity, delaying the injection time, disabling exhaust gas recirculation and by choking on the throttle. When a temperature of approx. 350 °C is exceeded behind the catalytic converter, a second post-injection is performed away from the main injection. This post-injection is so late that the fuel only evaporates and no more combustion takes place.However, this fuel vapour is converted on the catalytic converter and increases the gas temperature to up to 750 °C. The soot particles can thus be burned. A temperature sensor on the filter adapts the quantity of the remote post-injection in such a way that a temperature of 620 °C is reached in the underbody position, before the filter. The soot particles can thus be burned in a matter of minutes. With an increasingly high mileage (150,000 - 200,000 km), the filter becomes blocked, depending on oil consumption, and must be replaced. The remains of burned oil (oil ashes), which do not burn and accumulate in the filter, are responsible for this.253.0 l V6 TDI engine with common-rail injectionEngine managementSystem overviewFault prompting replacement SensorsControl unit for diesel injection system detects additional mass air flow from boost pressure and speedAir flow sensor G70Engine will not startEngine speed sensor G28Engine will not startHall sender G40Control unit for diesel injection system detects a fixed valueCoolant temperature sensor G62Control unit takes a fixed value of 90 °C - 5 %Fuel temperature sensor G81Engine control unit switches to nominal value and controlled operationFuel pressure sensor G247Engine runs at increased idle speedAccelerator pedal sensor with sensor for accelerator pedal position G79 and G185Reduction in fuel quantity – less powerBrake light switch F and brake pedal switch F47No effect, an entry is recorded in the fault memoryOxygen sensor G39No effectTemperature sensor for particle filter G235, G450Replacement value – boost pressure control reduced by 5 %Temperature sensor for turbocharger G20Fault memory entryDifferential pressure sensorAdditional signals: Speed control system Coolant temperature sensor Speed signal Terminal 50 Crash signal from airbag control unit Start request to engine control unit (Kessy 1 + 2) 26ActuatorsControl unit for automatic transmission J217Fault prompting replacementPiezo element for injector, cylinder 1 - 3 N30 - N32 Misfire detection via engine speed sensor, cylinder in question is disabled after several cycles Piezo element for injector, cylinder 4 - 6 N33 - N83 - N84Combination processor in dashboard insert J85Glow plug control unit J179 Relay for glow plugs J52 Glow plugs 1 - 4 Q6 Fault entry in control unit Relay 2 for glow plugs J495 Glow plugs 5 - 8 Q6AUTOSET ON/OF F UPAUTOOperating and display unit for air-conditioning system J255Throttle control unit N239/J338Remains openFuel pressure control valve N276The fuel pressure is regulated by the fuel level regulator in the high-pressure pump. Control unit function changes from regulating to control.ESP control unit J104Solenoid valve for exhaust gas recirculation N18No exhaust gas recirculation possibleButterfly valve adjuster V157 + V275By-pass flap is closed, exhaust gas recirculation is always cooledSwitch-over valve for exhaust gas recirculation cooler N345Butterfly valves remain openLeft/right solenoid valve for electro-hydraulic engine mount N144/N145 Control unit for diesel direct-injection system J248 Additional signals: Air-conditioning compressor Coolant preheater Fan stage 1 + 2 Relay for auxiliary heater J359 + J360 Auxiliary heater Z35 Data link connector Oxygen sensor heater Z19 Electric fanHeat control comes on when the engine temperature is exceeded.Fault memory entry onlyNo auxiliary heatingNo oxygen signal, oxygen sensor is switched off and the system is not adjustedFuel pump relay J17 Fuel pump (pre-feed pump) G6Engine starts with filled lines, driving behaviour problems with high fuel throughputs.325_019 273.0 l V6 TDI engine with common-rail injectionFunction diagramColour coding = Input signal = Output signal = Positive = Ground = Bi-directional = CAN BUSComponents A E45 E408 E415 F F47 F60 F194 Battery Switch for speed control system Engine start/stop button Switch for access and start authorisation Brake light switch Brake pedal switch Idle speed switch Clutch pedal switch (US model only) Temperature sensor 1 for catalytic converter Fuel pump Engine speed sensor Boost pressure sensor Oxygen sensor Hall sender Intake air temperature sensor Coolant temperature sensor Air flow sensor Sensor for accelerator pedal position Fuel temperature sensor Fuel level sensor -2Sensor -2- for accelerator pedal position Exhaust gas temperature sensor -1Fuel pressure sensor Exhaust gas temperature sensor in front of particle filter Pressure sensor 1 for exhaust gas Fuel pump relay Relay for electric fuel pump 2 Starter relay Control unit for glow time mechanism Control unit for diesel direct-injection system Voltage supply relay, terminal 30 Power supply relay, terminal 15 Throttle control unit Relay for low heating power Relay for high heating power Control unit for access and start authorisation Power supply relay, terminal 75 Starter relay Control unit for exhaust gas turbocharger M9 M10 N18 N30 N31 N32 N33 N83 N84 N144 N145 N276 N290 N335 N345 Lamp for left brake light Lamp for right brake light Exhaust gas recirculation valve Injection valve for cylinder 1 Injection valve for cylinder 2 Injection valve for cylinder 3 Injection valve for cylinder 4 Injection valve for cylinder 5 Injection valve for cylinder 6 Left solenoid valve for electro-hydraulic engine mount Right solenoid valve for electro-hydraulic engine mount Fuel pressure control valve Fuel metering valve Intake air switch-over valve Switch-over valve for exhaust gas recirculation coolerG20 G23 G28 G31 G39 G40 G42 G62 G70 G79 G81 G169 G185 G235 G247 G448 G450 J17 J49 J53 J179 J248 J317 J329 J338 J359 J360 J518 J694 J695 J724Q10-15 Glow plugs 1 - 6 S S204 V157 V275 Z35 Z19 Fuse Fuse -1-, terminal 30 Motor for intake pipe flap Motor for intake pipe flap 2 Heater element for auxiliary air heating Oxygen sensor heater1 2 3 4 5 6 7 8 9 10 11 12 13Fan stage 1 Fan stage 2 Engine speed To starter Terminal 50 Selector lever (P/N) Terminal 50, stage 1 Terminal 50, stage 2 CAN BUS L CAN BUS H CAN BUS Convenience CAN BUS Drive To lightsData link connector2830 15 X30 15 XJ3174J17SSS J695 J53 J694 J329SSSSS1112J338V275V157J724SJ179MMMMJ518+ 13 M G6 ()0 1G70 N18 N345 N276 N144 N145 N335 N290 J359 J360 M F/F47A01 2 3M9 Q10 Q11 Q12 Q13 Q14 Q15 Z35 M10E408 E415J248+ U G81 G235 G20 G448 G31 P G42 U P G62 P G247 G40 G28+ G39 N83 N84 F194 N30 N32 N33 N31 G79/G185 Z19G450123567891031325_040-+λ31293.2 l V6 FSI engineIntroductionA V6 engine with FSI technology has been developed for the first time for the new Audi A6. This engine is also used in the A8 and A4. The following development goals have been achieved here: – – – – – Compliance with the EU IV exhaust gas standard Reduced fuel consumption High performance High and ample torque Sporty and agile behaviour with a high level of comfort – Powerful, sportingly dynamic V6 sound Technical features are as follows: – Light-weight crankcase made of an aluminium/ silicon/copper alloy – Light plastic, two-position intake pipe – Balancer shaft for the elimination of first-order free inertia forces – Low-friction cylinder head with 4-valve roller-type cam followers – Engine control via rear chain drive – Front ancillary units are driven by Poly-V belts – Continuous camshaft adjustment on inlet and exhaust side – Siemens engine management with electronic throttle actuator control (E gas) – Emission control through continuous oxygen sensing, 2 catalytic converters close to the engine – P/N system for air mass metering325_05530The engine code and the engine number are located at the front right of the cylinder block.0 50 15 M1 AM EA 6E O6 KO UK A AU325_012Torque performance curve440220Torque in Nm Power in kWNmkW36014032010028060240 0 2000 4000 6000 800020Engine speed in rpm Technical dataCode Type Displacement in cm3 Power in kW (hp) Torque in Nm Engine speed Bore in mm Stroke in mm Compression Weight in kg Fuel Firing order Ignition gap Engine management Engine oil Exhaust standardAUK V engine with an angle of 90° 3123 188 (255) at 6,500 rpm 330 at 3,250 rpm 7,200 rpm 84.5 92.8 12.5 : 1 Approx. 169.5 ROZ 95/91 1-4-3-6-2-5 120° Siemens with E gas SAE 0W 30 EU IV313.2 l V6 FSI engineMechanicsCrankcase and crankshaft assemblyThe crankcase is made of an aluminium alloy. This over-eutectoid monoblock is manufactured using the chill-casting procedure. No bushings are cast in. Hard primary silicon particles, which are deposited in the liquefied material, are exposed in a special procedure. The bottom of the crankcase (bedplate) reinforces the crankcase and contains the four main crankshaft bearings.Reference Further information on this can be found in the Self-Study Programme 267.325_056The flood wall (oil plane) and the oil pump are integrated in the top of the oil pan. The bottom of the oil pan contains the oil level sensor.325_12932The crankshaft is a four-position steel crankshaft with a vibration damper. The con-rods are designed as trapezoid industrially-cracked con-rods. The faces are 1 mm wider compared with the 3.0 l V5 engine. The lift pin diameters were increased from 54 mm to 56 mm. This also increased the rigidity as well as the strength of the crankshaft.The con-rod measurements were reduced (from C70 to 33 Mn VS4) by changing the material used. The higher strength of the new material means that the higher gas forces can be transferred safely.325_063The forged piston has an FSI-specific combustion chamber well. The piston shaft is coated with a wear-resistant ferrous coating. Piston cooling is performed using oil spray jets.325_045333.2 l V6 FSI engineEngine ventilation Engine ventilation involves pure head ventilation. This means that the blow-by gasses are removed only through the cylinder head covers. A rough separation of the oil is performed in the cylinder head covers using a labyrinth. The blow-by gasses are routed out of the cylinder head covers and into the internal engine V compartment. This contains the dual-cyclone oil separator, which diverts the separated oil directly into the crankcase and also heats the purified blow-by gasses to 20 - 25 °C. The application of heat prevents the pipes and the pressure-regulating valve from freezing. Advantages: – Good package – Protection against freezing The blow-by gasses, which have a low oil content, are passed on to the intake pipe via the pressureregulating valve and supplied to the combustion system. The use of active crankcase ventilation also prevents freezing. Here, the blow-by volume flow is raised in the near-idle speed range. To do this, fresh air is removed from the intake pipe and routed directly into the crankcase. This has a positive effect on the oil quality since more water and fuel residues are removed from the engine oil due to the higher throughput of blow-by gasses. The connection is set up in front of the throttle and on the V compartment lid. To prevent the blow-by gasses from being sucked in (e.g. as a result of the pressure difference between the crankcase and the intake pipe at full speed and when the throttle is open), a return valve is integrated in the pipe.Ventilation pipe Pressure-regulating valve Intake pipeVentilation pipeCylinder head coverVentilation pipesCylinder head coverFine separator325_074 Dual-cyclone Return valve Oil reservoir 34Pressure-regulating valve The pressure-regulating valve regulates the gas throughput and pressure compensation of the crankcase ventilation system. It is a spring-loaded diaphragm valve. The control connection is linked to the intake manifold. The intake manifold pressure works on the diaphragms. This actuates the valve. There is a strong vacuum in the intake manifold when the throttle is closed. This vacuum closes the pressure-regulating valve against the spring force. The shaft seals may be damaged if the pressureregulating valve is faulty (defective diaphragms). If the pressure-regulating valve does not close, an excessively high vacuum builds up via the intake manifold in the crankcase. The shaft seals are pulled inward and can then start to leak. If the valve does not open, too much pressure builds up in the crankcase. This can also damage the shaft seals. Oil supply – Forced-feed lubrication designed for oil specification SAE 0W 30 – Oil pressure control on pure oil-side – Duocentric oil pump with cold-start valve as overload protection for oil cooler and oil filter – The oil supply for the camshaft adjusting motors and the head-side chain modules has been separated from the cylinder head oil supply. As a result, the oil pressure in the cylinder head could be throttled back. – New oil filter module means that filters can be changed faster and in a more service-friendly way.DiaphragmsAtmospherePressure from cylinder crank case325_114 Intake manifold pressureOil filter moduleOil pump drive Balancer shaftDuocentric oil pumpPlate oil cooler Forced oil circuitReturn on pure-oil side Return pipe 325_073 353.2 l V6 FSI engineEngine controlChain drive C Bank 2 Chain drive B Bank 1Chain drive ABalancer shaftChain drive D325_057The chain drive is located at the power-output side of the engine. It is arranged over two levels. Four chains are installed in total. 3/8-inch sleeve chains are used for chain drive A, B and C. A single roller chain is used for chain drive D. The chains are designed for the service life of the engine. – Chain drive A: Crankshaft intermediate sprockets – Chain drive B/C: Camshaft drive – Chain drive D: Oil pump via plug-in shaft and balancer shaft The chains are lubricated using oil spray, which is controlled by the camshaft adjusters. The chain drives A, B and C are tensioned using mechanical chain tensioners with a hydraulic damping function. Chain drive D is tensioned using a simple mechanical tensioner. Low-friction guide elements guarantee the smooth running of the entire engine control system.Balancer shaft The masses rotating and oscillating in the engine produce vibrations, which cause noise and rough operation. Free inertia forces of the first order reduce the level of comfort and can be balanced by the balancer shaft. The shaft is made of GGG 70. It is fitted in the internal engine V compartment and supported on two bearings. Oil is supplied via two rising bores on the main bearing assembly. It is driven at engine speed by the chain drive. The direction of rotation of the balancer shaft is reversed in th36Cylinder head – Aluminium cylinder head – FSI inlet pipes with variable loading movement; the horizontal pipe division produces a tumble effect – Valve actuation via roller-type cam followers with smooth hydraulic clearance compensation – Valve guide made of sintered material (chromium-plated valves are thus required) – Spring retainer made of (hardened) aluminium with additional wear-resistant washer – Simple valve spring – 2 camshafts installed for each cylinder head – Smooth inlet camshaft adjusters (adjustment range up to a crank angle of 42°) – Smooth exhaust camshaft adjusters (adjustment range up to a crank angle of 42°) – 4 hall senders for camshaft position detection – Camshaft bearing lid designed as a retaining frame (attached via fixing pins) – Cylinder head gasket as a multi-layer metal seal with silicon pads on the chain housing – Detached plastic cylinder head cover with integrated oil separator (as a labyrinth)CoverBondal lidRetaining frameFitted camshafts 325_058Cylinder head373.2 l V6 FSI engineCamshaft adjusters The camshaft adjusters work according to the well-known hydraulic rocker engine principle. They are manufactured by Denso. Both the inlet camshaft adjuster and the exhaust camshaft adjuster have an adjusting range of up to a crank angle of 42°. The rotor and stator are weight-optimised and are made of aluminium. Spring-loaded sealing elements are used for the radial sealing of each of the four pressure chambers. The adjusters must be locked in a defined position until the required engine oil pressure is built up after starting the engine. Locking takes place in the "Late" position. Inlet camshaft adjuster Locking is free from play here.Exhaust camshaft adjuster A return spring supports the movement of the adjuster into the Early position. When the engine is stopped, the adjuster is locked in the Late position and the return spring is tensioned. A limited amount of play has been allowed here at the locking pin so that the adjuster can be unlocked safely.325_12838Intake system The intake system, from the intake opening at the front of the vehicle to the pure air outlet at the filter element, is the same for all engines except for the 2.4 l V6 engine. A cylindrical air filter cartridge is used to increase the useful life of the air filter. An outlet valve in the filter housing has been used to optimise the discharge of water from the filter housing. If the engine requires a large amount of air, the engine control unit (active opening) activates the solenoid valve N335 and a vacuum modulator opens the wheel housing inlet. The passive opening of the wheel housing inlet is activated if an excessively high vacuum is created in the air filter housing (e.g. obstruction of the intake opening at the front of the vehicle). The increased vacuum forces the flap of the wheel housing inlet open. The raw-air intake system is fitted with an additional intake pipe from the wheel housing with flow-optimised cross-sections. A snow strainer and hot-air intake system are also available for cold countries. The hot-air intake system is controlled by a wax extension element. The throttle body is a single-flow system and includes water-heating as an option.Note: Engine management is performed without an air flow sensor, i.e. the mass air flow is calculated from the engine speed and intake manifold pressure.Flexible intake pipeFlexible intake pipeAir inlet at front of vehicle325_059393.2 l V6 FSI engineThe switch-over intake pipe is disconnected acoustically in order to reduce noise. It has two settings – short and long intake method – for power and torque. The switching is controlled by a solenoid valve. The pipe is returned to its original setting by spring force. The vacuum accumulator is integrated and has a design function. The duo-sensor (pressure/temperature) as well as the mounting point for the pressure-regulating valve of the ventilation system are located in the intake pipe.Two selector shafts are used for the longitudinal switching of the switch-over intake pipe. These are connected together via a gear set. The plastic flaps have an airfoil section, which improves the flow. They have an elastomer extrusion-coating to protect against leakage losses.Note: The engine control unit continuously monitors the position of the intake pipe flaps using hall sensors.Duo-sensorPressure-regulating valvePosition feedback of intake pipe flap325_131 Vacuum modulator for switch-over intake pipe Vacuum modulator for loading switch-over flaps Electric switch-over valve40The intake pipe in the cylinder head is divided horizontally into two halves by an inserted refined-steel plate. It is possible to close off the lower intake pipe using the pre-positioned intake pipe flaps. This increases the flow intensity and causes a rolling movement (tumble) of the air columns in the combustion chamber. The best possible swirling of the fuel-air mixture is achieved in this way. The intake pipe flaps are fitted eccentrically in order to reduce any flow losses. As a result, they are completely integrated into the pipe wall in open position. The 2-stage adjustment of the intake pipe flaps is achieved via vacuum, while spring force is responsible for readjustment. In normal position, the flaps are closed as a result of spring force (small cross-section). The position is reported back via hall sensors.325_127325_061Exhaust system The exhaust manifold is a cast-iron part. Connections to the cylinder head are divided into individual flanges in order to prevent thermal stress. The exhaust gasses are combined from cylinder 3 to cylinder 2 to cylinder 1, i.e. not a cloverleaf model. The oxygen sensor is fitted at the best possible flow point for all three cylinders, thereby allowing cylinder-selective oxygen sensing. Engine management can thus have a greater influence on the fuel/air mix formation of each cylinder.325_062413.2 l V6 FSI engineFuel supplySystem overviewHigh-pressure sensor G247Injection nozzles 4 - 6Low-pressure sensor G410 Quantity control valve N290Pressure relief valveInjection nozzles 1 - 3Fuel filter High pressureNo pressure To engine control unit Battery Ground Power electronics 325_041The fuel supply system is divided into two systems, namely the low-pressure and the high-pressure system. The low-pressure system is a requirement-regulated fuel system. Here, the power of the electric fuel pump (EFP) is regulated by performance electronics via PWM signal (pulse width-modulated). Signal transfer from the engine control unit to the performance electronics also takes place via the PWM signal. There is no fuel return line. The low-pressure sensor N410 ensures that the variable pressure is maintained. Advantages – Energy saving due to the lower power consumption of the electric fuel pump – Lower heat absorption in the fuel – only the fuel quantity that is currently required is compressed – The service life of the electric fuel pump is extended – Reduced noise, particularly at idle speed – On-board diagnosis of the low-pressure system and the shock absorber of the high-pressure system is possible (via the low-pressure sensor)The pre-feed pressure must be increased by 2 bar for the following operating states: – When stopping the engine (electric fuel pump after-run) – Before starting the engine (fuel pump fore-run) when the ignition is on or when the driver’s door contact is up – While starting the engine and up to around 5 seconds after engine start – When warm-starting and when the engine is warm – the time depends on the temperature (t 5 seconds) in order to prevent the formation of vapour bubblesNote: When the pump control unit or the engine control unit is replaced, the pump control unit must always be adapted accordingly using the specified troubleshooting steps.42High-pressure system The high-pressure system is made up of the following components: – High-pressure fuel distributor panel, integrated in the intake manifold flange, with pressure sensor and pressure-control valve – High-pressure fuel injection pump – High-pressure fuel lines – High-pressure injection valves325_060Single-piston high-pressure pump This is manufactured by Hitachi. It is driven at the end of the inlet camshaft of bank 2 via a triple cam. It produces a fuel pressure of between 30 and 120 bar. The pressure is set by the quantity control valve N290, depending on the nominal value. The fuel pressure sensor G247 monitors the pressure here. The pump does not have a leakage line, but feeds the controlled fuel back into the flow-side internally. The low-pressure fuel sensor G410 is integrated in the pump. This system is a requirement-regulated high-pressure pump. This means that only the quantity of fuel stored in the engine control unit map is fed into the high-pressure rail. The advantage of this system compared with a continuous-feed high-pressure pump is the reduced drive power. Only the fuel that is actually needed is fed into the system.Quantity control valve N290325_124Low-pressure sensor G410433.2 l V6 FSI engineIntake stroke The shape of the cam and the force of the piston springs move the pump piston downwards. The increased space in the inside of the pump causes the fuel to flow in. The quantity control valve ensures that the low-pressure valve remains open. The quantity control valve is de-energised.High-pressure valveFuel feed from tankQuantity control valve N290High-pressure connection to railLow-pressure inlet valve325_120Useful stroke The cam moves the pump piston upwards. Pressure still cannot be built up because the quantity control valve is de-energised. This prevents the low-pressure inlet valve from closing.325_119Pressure stroke The engine control unit now supplies current to the quantity control valve. The magneto armature is drawn up. The pressure inside the pump presses the low-pressure inlet valve into its seat. If the pressure inside the pump exceeds the rail pressure, the return valve is pushed open and fuel is delivered to the rail.325_11844Like the high-pressure pump, the high-pressure injection valves are also manufactured by Hitachi. Their job is to inject fuel directly into the combustion chamber at the right time and in the right quantity. The engine control unit activates the injection valves by applying approx. 65 volts of power. The quantity of fuel is determined by the opening time and the fuel pressure. The combustion chamber is sealed with a Teflon seal, which must always be replaced following disassembly.Fine strainerMagnetic coilArmature clearance of 4/100 mmNote: Replace the Teflon seal using the special tool T10133.Magneto armatureNozzle needleTeflon seal 325_042FSI operating methods The FSI combustion procedure is essentially restricted to homogeneous operation. The "layer loading operation" method is not implemented for the following reason. In the lower engine speed range and with a low engine load, a high-volume 6-cylinder engine has a lower thermal load than a 4-cylinder engine with low piston displacement. Due to the low exhaust gas temperature, the NOx storage catalytic converter does not reach its operating temperature of up to 600 °C. The "homogeneous operation" method is divided into two operating states. 1. Homogeneous operation with closed intake manifold flap The intake manifold flap is closed in the engine speed range up to approx. 3,750 rpm or with an engine load of up to 40 %, depending on the map. The lower intake pipe is closed off. The mass air flow, which is sucked in, is accelerated via the top intake pipe and flows in rolls (tumbles) into the combustion chamber. Injection takes place in the intake tract. 2. Homogeneous operation with open intake manifold flap The intake manifold flap opens at an engine speed of approx. 3,750 rpm or with an engine load of more than 40 %. This ensures high air throughput at a high engine speed and engine load. This is supported by a high volume-dimensioned two-stage intake pipe, which has switched to suit the performance range (short intake pipe). Injection also takes place in the intake tract here.453.2 l V6 FSI engineEngine managementSystem overviewFault prompting replacement SensorsFault memory entry / replacement model / MIL onManifold pressure sensor G71 Intake air temperature sensor G42Fault memory entry / compensating engine speed from camshaft speed / MIL on Fault memory entry / no camshaft adjustment / loss of power / MIL onEngine speed sensor G28Hall sender G40 Hall sender G163 + G300 Hall sender G301Fault memory entry / MIL on / EPC onThrottle control unit J338 Angle sensor G188/G187Fault memory entry / MIL on / EPC onSensor for accelerator pedal position G79 Sensor 2 for accelerator pedal position G185 Hand switch F36 + F194 only Brake light switch F Brake pedal switch for GRA F47 Fuel pressure sensor G247 Low-pressure fuel sensor G410Fault memory entry in transmission control unitFault memory entry / no high pressure possible / loss of power / MIL on Fault memory entry / no low-pressure regulationFault memory entry / intake manifold flaps screwed down / loss of power / MIL onPotentiometer for intake manifold flap 1 G336 Potentiometer for intake manifold flap 2 G512Fault memory entry / replacement model / loss of powerKnock sensor G61, G66Fault memory entry / replacement model / loss of powerCoolant temperature sensor G62Fault memory entry / intake manifold flaps set / loss of power / MIL onValve for intake manifold flap N316Fault memory entry / loss of powerSensor for switch-over intake pipe position G513Fault memory entry / no oxygen sensing / MIL onOxygen sensor ahead of catalytic converter G108 + G39 Oxygen sensor behind catalytic converter G130 + G131Additional signals: J393 (door contact signal), J518 (start request), J695 (output from start relay, terminal 50 stage 2), J53 (output from start relay, terminal 50 stage 1), J518 (terminal 50 on starter), J364 (auxiliary heating), E45 (speed control system) 46ActuatorsFault prompting replacementFuel pump control unit J538 Fuel pump V276Fault memory entryControl unit for Simos J361 Injection valves for cylinders 1 - 6 N30 - 33 and N83, N84 Fault memory entry / misfiring / cylinder deactivation / MIL onIgnition coil 1 with final output stage N70 Ignition coil 2 with final output stage N127 Ignition coils N70, N127, N291, N292, N323, N324Fault memory entry / misfiring / cylinder deactivation / MIL onThrottle control unit J338 Throttle drive G186 Control unit for ABS J104 Power supply relay for engine components J757Fault memory entry / MIL on / EPC onFault memory entry / no high pressure possible / loss of power / MIL onSolenoid valve for carbon canister system N80Fault memory entry / no tank ventilation possible / MIL onSender for steering-angle sensor G85Valve for fuel metering N290Fault memory entry / no high pressure possible / loss of power / MIL onData link connector Control unit for airbag J234 Valve for register manifold switching N156 Fault memory entry / loss of powerValve 1 + 2 for camshaft adjustment N205/N208 Valve 1 + 2 for exhaust camshaft adjustment N118/N119Fault memory entry / loss of power / MIL onValve for intake manifold flaps N316 Control unit for automatic transmission J217 Solenoid valves for electro-hydraulic engine mount N144/N145 Control unit with display in dashboard insert J285 Control unit for oxygen sensors J754 Oxygen sensor heating Z19, Z28, Z29, Z30 Pre-catalytic converter 1 G39 and pre-catalytic converter 2 B108 Post-catalytic converter G130/G131 Relay for additional coolant pump J469 and pump for coolant after-run V51Fault memory entry / butterfly valves set / loss of power / MIL onFault memory entryFault memory entry / no oxygen sensing / MIL onA/C operating and display unit E87Intake air switch-over valve N335Fault memory entryAdditional signals: Fan stage 1 / PWM cooler fan 1 J293 47325_1883.2 l V6 FSI engineFunction diagramColour coding = Input signal = Output signal Components A E45 E408 E415 F194 G G28 G39 G40 G42 G61 G62 G66 G71 G79 G108 G130 G131 G163 G169 G185 G186 G187 G188 G247 G300 G301 G336 G410 G501 G513 G512 J53 J271 J317 J329 J338 J361 J496 J518 J538 J694 J695 J757 Battery Switch for speed control system Engine start/stop button Switch for access and start authorisation Clutch pedal switch (manual transmission only) Sender for fuel level indicator Engine speed sensor Oxygen sensor Hall sender Intake air temperature sensor Knock sensor 1 Coolant temperature sensor Knock sensor 2 Manifold pressure sensor Sensor for accelerator pedal position Oxygen sensor 2 Oxygen sensor behind catalytic converter Oxygen sensor 2 behind catalytic converter Hall sender 2 Fuel level sensor -2Sensor -2- for accelerator pedal position Throttle drive for electric gas actuation Angle sensor -1- for throttle drive Angle sensor -2- for throttle drive Fuel pressure sensor Hall sender 3 Hall sender 4 Potentiometer for intake manifold flap 1 Fuel pressure sensor for low pressure Sender -1- for input shaft speed Sender for switch-over pipe position Potentiometer for intake manifold flap 2 Starter relay Power supply relay for Motronic Voltage supply relay, terminal 30 Power supply relay, terminal 15 Throttle control unit Control unit for Simos Relay for auxiliary coolant pump Control unit for access and start authorisation Fuel pump control unit Power supply relay, terminal 75 Starter relay Power supply relay for engine components N70 N80 N83 N84 N127 N144 N145 N156 N205 N208 N290 N291 N292 N316 N318 N319 N323 N324 N335 S S204 V51 V276 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 x + y Ignition coil 1 with final output stage Solenoid valve 1 for carbon canister Injection valve for cylinder 5 Injection valve for cylinder 6 Ignition coil 2 with final output stage Left solenoid valve for electro-hydraulic engine mount Right solenoid valve for electro-hydraulic engine mount Valve for register manifold switching Valve -1- for camshaft adjustment Valve -2- for camshaft adjustment Fuel metering valve Ignition coil 3 with final output stage Ignition coil 4 with final output stage Valve for intake manifold flap Valve -1- for exhaust camshaft adjustment Valve -2- for exhaust camshaft adjustment Ignition coil -5- with final output stage Ignition coil -6- with final output stage Intake air switch-over valve Fuse Fuse 1, terminal 30 Pump for coolant after-run Fuel pump 1 Fuel level for dashboard insert Fuel level for dashboard insert (for quattro only) Terminal 87, from control unit for auxiliary heating Door contact signal Terminal 50, stage 1 Terminal 50, stage 2 Terminal 50 Selector lever position (P/N) Engine speed Fan stage 1 Redundant brake light signal Brake light signal CAN Drive data bus, High CAN Drive data bus, Low CAN Convenience data bus CAN Drive data bus To lights connections within the function diagram = Positive = Ground = Bi-directional = CAN BUSN30 ... Injection valves for cylinders 1 - 4 ... N334830 15 X30 15 XJ3174SSJ757 J695 J53 J694 J329 X S S SSSSS1112YJ518+ 13G39G130 + + + + P V51 G40 G163 G300 G301 G62 G247 P G410 P G42 G71N2P2λG108 G131 N80 N144 N145 N239 N290 N316 N335 N205 N208 N318 N319 J496MA ()0 1 01 2 3E408 E41531J2483 X J538 M F194 N70 Y456789101112V276 MGG169N127 N30 N31 N32 N33 N83 N84 G187 G188 J338 G186 G79 G185N291 N292 N323 N324 1 2 13 14 G28 G61 G66 G513 G336 G512P Q 3131325_075 493.2 l V6 FSI engineServiceSpecial toolsHere you see the new special tools for the 3.0 l V6 TDI and the 3.2 l V6 FSI engine.Engine and gearbox holder VAS 6095 Universal mounting point Engine-specific mounting point325_207 325_206 T40048 Assembly device for crankshaft sealing ring T40049 Adapter Crankshaft turns on flywheel side325_208 T40053 Counterer for high-pressure pump wheel T40055 Socket wrench for high-pressure line 325_209325_210 T40058 Adapter Crankshaft turns belt pulley 325_211 T40060 2 alignment pins for chain sprocket50325_212 T40061 Adapter for camshaft T40062 Adapter for chain sprocket325_213325_214 T40064 Pullers for high-pressure pump wheel T40069 Fixing pin325_139325_140 T40070 Camshaft fixing device32