Service TrainingCommercial VehiclesSelf-study programme 371The 2.5l TDI engines in the CrafterDesign and functiones, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngn AG. Volkswagen AG do es n wage s k l ot g o yV ua b ran ed s i tee r o h t or u ac a ssility ab y li an pt cerrectness of i t to the co nf o r m spec atio h re n in witthi sd o cu m enht rig py Co t.agen lksw Vo byAG.Prote cted byc o p yri gh t . C op yiFor the Crafter from Volkswagen, a new 5-cylinder diesel engine generation with common rail injection system has been developed. This new engine generation is based on the tried and tested 2.5l TDI engine (with sales into the millions) with 5-cylinders and a distributor-type injection pump in the LT2 and Transporter T4.lkswagen AG The emphasis during development was placed on fulfilment of the exhaust and AG. Voemissions doesimprovement agen ksw not l o V of the engine acoustics and also reduction in operating and gu by repair costs. aes, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngIn this self-study programme, you can find out generation.ed ris o h t au the design about ssand features of this newran tee or ac engineility ab y li an pt cerrectness of i t to the co nf o r m spec atio h re n in witthi sd o cu m enNEWThe self-study programme represents the design and function of new developments! The contents will not be updated.For latest inspection, adjustment and repair instructions, please refer to the appropriate workshop literature.2ht rig py Co t.agen lksw Vo byAG.Prote cted byc o p yri gh t. C op yiS371_001Caution NoteAt a glanceIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4Engine mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10System overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Engine management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36Functional diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58Serviceurposes, in part or in wh ole, cial p is n mer m ot p o c erm or e t a itte v i r d pTest your knowledge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63rrectne s s o f i t to the co n form spec atio h re n wit i n thi sd o c um enr fo ngun le. Volkswagen AG gen AG doe swa k l o . . . . . .b .y.V . . . . . . . . . . . . . . . . . . . s .n .o. .u . . . . . . tg ara d e nte is r o eo th u ra a c s s. . . . . . . . . . . . . . . . 62ility ab y li an pt ceht rig py Co t.agen lksw Vo byAG.Prote cted by c o py rig ht . C op yi3IntroductionInstalled in the Crafter is the 2.5 l TDI engine in four outputs from 65kW to 120kW. All engine variants are derived from a uniform foundation model, which is based in its geometrical basic dimensions on the tried and tested 5-cylinder TDI engine with distributor-type injection pump from the LT2 and Transporter T4. Depending on the output, they are adapted both in the mechanical configuration and also the engine management system. In order to meet the rising demands in output, acoustics, emissions, consumption and extended service intervals, a large number of engine components have been revised. Of particular importance here is the conversion of the engine to common rail injection technology. Equipped with a catalytic coated diesel particulate filter, all engine variants fulfil the EURO 4/EU4 emissions standard. Engines with EURO 3/EU3 emissions standard have no diesel particulate filter.es, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngAG. Volkswagen AG d agen oes ksw l o Electric exhaust gas not gu yV b ara ed recirculation valve nte ris o eo th u ra a c s sility ab y li an pt cerrectness of i t to the co nf o r m spec atio h re n in witAdjustable turbochargerthi sd o cu m enOil level sender for extended service interval4ht rig py Co t.agen lksw Vo byAG.Prote cted by c o py rig ht . C op yiUpright oil filter moduleS371_002Technical features●● ● ● ●Common rail injection system with piezo injectors Catalytic coated diesel particulate filter Electric intake manifold flap Electric exhaust gas recirculation valve AG. Volkswagen AG d Exhaust gas recirculation cooler agen oksw Vol by d e ris tho u a ss● ● ●●Adjustable exhaust gas turbocharger Upright oil filter module Crankcase breather with cyclonic oil separator Oil level sender for extended service intervales n ot g ua ran tee or acility ab y li an pt ceurposes, in part or in wh ole, cial p is n mer m ot p o c erm or e t a itte v i r d pun leCyclonic oil separator Common rail injection system with piezo injectorsrrectne s s o f i t to the co n form spec atio h re n wit i n thi sd o c um enElectric intake manifold flapr fo nght rig py Co t.agen lksw Vo byAG.Prote cted byc o p yri gh t. C op yiExhaust gas recirculation coolerS371_0035IntroductionTechnical dataThe 2.5l 65kW TDI engineEngine code Type Displacement Bore Stroke Valves per cylinder Compression ratio Max. output Max. torque Engine management Fuel Exhaust gas treatment BJJ 5-cylinder inline engine 2461cm3 81.0mm 95.5mm 2 16.8 : 1 65 kW at 3500 rpm 220 Nm at 2000 rpm Bosch EDC 16 C Diesel with at least 51CN100 Exhaust gas recirculation with exhaust gas cooler; AG. Volkswagen AG d catalytic coated agen oes ksw not l 50 o diesel particulate filter by V gu a 0 1000 40 20 0 4000 250 100 300 120 350 140Performance and torque graphTorque [Nm]2008015060Emissions standardes, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e nged ris EU4/EURO 4 ho t au ssran tee or ac 2000 3000Engine speed [rpm]S371_262The 2.5l 80kW TDI engineEngine code Type Displacement Bore Stroke Valves per cylinder Compression ratio Max. output Max. torque Engine management Fuel Exhaust gas treatment BJK Performance and torque graph350 3005-cylinder inline engine 2461cm3 81.0mm140 12095.5mm 216.8 : 1250100280 Nm at 2000 rpm Bosch EDC 16 C Diesel with at least 51CNProte cted by c o py rig ht . C op yi2008050Emissions standardEU4/EURO 4 EURO 3/EU3 (without diesel particulate filter and exhaust gas cooler)06agen lksw Vo byAG.Exhaust gas recirculation with exhaust gas cooler; catalytic coated diesel particulate filter10010002000Engine speed [rpm]ht rig py Co t.1506040 20 030004000S371_264Output [kW]80 kW at 3500 rpmTorque [Nm]Output [kW]ility ab y li an pt cerrectness of i t to the co nf o r m spec atio h re n in witthi sd o cu m enThe 2.5l 100kW TDI engineEngine code Type Displacement Bore Stroke Valves per cylinder Compression ratio Max. output Max. torque Engine management Fuel Exhaust gas treatment BJL 5-cylinder inline engine 2461cm3 81.0mm 95.5mm 2 16.8 : 1 100 kW at 3500 rpm 300 Nm at 2000 rpm Bosch EDC 16 C Diesel with at least 51CN Exhaust gas recirculation with exhaust gas cooling; catalytic coated diesel particulate filter EU4/EURO 4100 40 20 0 1000 2000 3000 4000 250 100 300 120 350 140Performance and torque graphTorque [Nm]200801506050Emissions standard0Engine speed [rpm]S371_266The 2.5l 120kW TDI engineEngine code Type Displacement Bore Stroke Valves per cylinder Compression ratio Max. output Max. torque Engine management Fuel Exhaust gas treatment BJM 2461cm3 81.0mmes, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ng5-cylinder inline engineAG. Volkswagen AG d agen oes ksw not l o V gu y b ara d nte ise r Performance and o eo h t u ra torque graph a c s s350 30014095.5mm120216.8 : 1250100200350 Nm at 2000 rpm80Bosch EDC 16 C Diesel with at least 51CN150 10060Exhaust gas recirculation with exhaust gas cooling; catalytic coated diesel particulate filter405020 0Emissions standardEngine speed [rpm]agen lksw Vo byProte cted byht rig py Co t.AG.c o p yri gh t. C op yiEU4/EURO 4 EURO 3 (without diesel particulate filter)0 1000 200030004000S371_260Output [kW]120 kW at 3500 rpmTorque [Nm]Output [kW]ility ab y li an pt cerrectness of i t to the co nf o r m spec atio h re n in witthi sd o cu m en7IntroductionThe emissions standardsThe diesel engine of the Crafter meets the European emissions standards EU4 and EURO 4. To monitor the exhaust gas relevant components, all vehicles have European onboard diagnosis (EOBD). EOBD is prescribed in the member states of the European Union for type approval as of 1st January 2006 even for commercial vehicles. In some countries, the 2.5l TDI engine is also offered as a variant with EU3/EURO 3 emissions standard. These engines are not fitted with a diesel particulate filter.Crafter registered for passenger transportation (emissions standard EU4)The emissions standard EU4 applies for all vehicles registered for the transportation of passengers, for example a Crafter with up to 9 seats to transport passengers. For type approval, the exhaust emissions of the vehicles are determined on a test bed or rolling road with a fixed driving cycle and a prescribed method of measurement. The harmful emissions are calculated in grams per kilometre (g/km).S371_052and a kerb weight of 1.76 t.es, in part or in w l purpos hole ercia , is n m ot p om c r erm o e t a itte riv du p or nl f e g nAG. Volkswagen AG d agen oes ksw not l o V gu y b Emissions thresholds for diesel vehicles ara d nte ise r o eo h The emissions thresholds shown in the diagram refer t u ra g/km a c s s 2.5 t to vehicles with a maximum permissible weight 0.8 0.740.6 0.46 0.4 0.39S371_386ility ab y li an pt cerrectness of i t to the co nform spec at i h re o n wit in t his0.20.06COCarbon monoxideHC + NOXHydrocarbons and nitrogen oxidesNOXNitrogen oxidesPMSoot particlesIf you require further information about European onboard diagnosis on diesel vehicles, please refer to self-study programme SSP 315 “Euro onboard diagnosis for diesel engines”.ht rig py Co t.do c um en8agen lksw Vo byAG.Prote cted byc o p yri gh t. C op yiCrafter registered for commercial use (emissions standard EURO 4)The emissions standard EURO 4 applies for all vehicles registered for commercial use (LCVs, HGVs). In order to restrict the amount of work necessary for type approval of these vehicles on a test bed or rolling road (e.g. for custom body manufacturers), the harmful emissions are determined on an engine performance test bed. This inspection is sub-divided into three test procedures. The harmful emissions are AG. Volkswagen AG d agen in grams per oes calculated kilowatt-hour (g/kWh). n lkswot g ua ran tee or acS371_156 Emissions thresholds for ESC testg/kWh 4.0es, in part or in w l purpos hole ercia , is n m ot p om c r erm o e t a itte riv du p or nl f e g no yV db e ris tho u a ss ESCtestility ab y li an pt ceS371_1043.53.0The ESC test stands for European Steady Cycle. With this procedure, the gaseous harmful substances and particulate emissions are determined in 13 different operating conditions of the engine.rrectness of i t to the co nform spec at i h re o n wit in t his2.01.5 0.461.0ELR test0.02COCarbon monoxideHCHydrocarbonsNOXPMNitrogen oxidesSoot particlesELR is the abbreviation for European Load Response. With this testing procedure, the smoke opacity is determined in a test cycle as a measurement for the soot particles suspended in the exhaust stream of a diesel engine. The permissible threshold for smoke opacity is 0.5 1tr./m.do c um enht rig py Co t.Emissions thresholds for ETC testg/kWh 4.0 4.0 3.53.02.01.00.55 0.03ETC means European Transient Cycle. This test is prescribed for engines equipped with exhaust gas treatment systems, for example a diesel particulate filter. During this test, the exhaust emissions are determined in a test cycle in which the load and speed are calculated for each second. The test cycle lasts for 1800 seconds.AG.COCarbon monoxideHCHydrocarbonsNOXNitrogen oxidesPMSoot particlesagen lksw Vo byS371_102Prote cted by c o py rig ht . C op yiETC test9Engine mechanicsThe cylinder blockThe cylinder block of the 2.5l TDI engine is made from cast iron with flake graphite. In its basic geometric dimensions it is based on the 2.5 l TDI engine with distributor-type injection. The transmission connection was adapted to the new manual gearbox in the Crafter.es, in part or in w l purpos hole ercia , is n m ot compe rm itte dun len AG. Volkswagen AG do es n wage s k l ot g o yV ua b ran ed s i tee r o h t or u ac a ssility ab y li an pt ceS371_128rrectness of i t to the co nform spec a t i h re o n in wit thi sThe crankshaft driveCrankshaftDue to the high compression pressures and temperatures, the components of the crankshaft drive system have been altered in many areas compared with the previous engine with distributor-type pump. The steel crankshaft is die cast and is mounted in six positions. The diameter of the conrod journals has been made larger by 3mm. The load capability of the crankshaft against torsional forces has thereby been improved.r te o iva r rp fo g ndo c um en10ht rig py Co t.agen lksw Vo byAG.Prote cted byc o p yri gh t . C op yiS371_004PistonPiston crown recess PistonThe pistons are manufactured from an aluminium alloy by gravity die casting. Due to the 25° angled fuel injectors, the piston crown recess is positioned asymmetrically in the piston. The pistons of the engines with performances from 100kW and 120kW have a ring-shaped cooling channel. Oil is sprayed via the oil injectors in the cooling channel to improve cooling of the piston crown.Ring shaped cooling channelConrod small endConrodun len AG. Volkswagen AG do es n wage s k l ot g o yV ua b ran ed s i tee r o h t or u ac a ssConnecting rodes, in part or in w l purpos hole ercia , is n m ot comThe small conrod end has a trapezoidal shape. Thanks to this trapezoidal shape, the combustion pressures are distributed over a large surface area and the conrod and also gudgeon pin are placed under less strain.ility ab y li an pt cepe rm itte drrectness of i t to the co nform spec a t i h re o n in wit thi sS371_220The cylinder headr te o iva r rp fo g nThe cylinder head has been revised in some areas compared with the previous engine with distributor-type injection pump. The flow distribution of the coolant has been optimised. The inlet ports have been revised, resulting in improved swirl and flow of the incoming air. The position of the holes for the glow plugs has been adapted to the geometry of the new ceramic glow plugs.do c um enht rig py Co t.S371_257agen lksw Vo byAG.Prote cted byc o p yri gh t . C op yi11Engine mechanicsCylinder head gasketBackground supportA newly designed cylinder head gasket reduces the distortion of the cylinder head and the cylinder holes. In this way, sealing of the combustion chambers has been improved. The cylinder head gasket has a 5-layer structure and features two special characteristics:● ●Height-profiled combustion chamber stopper “Background support”Background supportS371_252 Combustion chamber stopperSchematic diagram of cylinder head gasket cross sectionBackground supportCarrier plateAG. Volkswagen AG d agen oes ksw not l o V gu y b ara d S371_314 nte ise r o eo h t u ra a c Stopper s sProfile platesun lepe rm itte dility ab y li an pt ceS371_279es, in part or in w l purpos hole ercia , is n m ot comHeight-sectioned combustion chamber stopperCombustion chamber stopper refers to the sealing edge on the cylinder head bore. It has a height-profiled design. This means that the edge profile along the combustion chamber has different heights. Thanks to this special forming, an equal distribution of the tightening forces is achieved on the combustion chambers. Distortions at the cylinder bores and any occurring vibrations in the sealing gaps are thereby reduced.r te o iva r rp fo g nrrectness of i t to the co nform spec a t i h re o n in wit thi sTightening forcesCombustion chamberdo c um enS371_350agen lksw Vo byAG.Prote cted by12ht rig py Co t.c o p yri gh t. C op yi“Background support”Background supportBackground support refers to the profile in the area of both outer cylinders of the cylinder head gasket. The background support results in an equal distribution of the tightening forces in these areas. In this way, bending of the cylinder head and distortion of the outer cylinders is reduced.S371_342Distribution of tightening forces without background support Tightening forcesDistribution of tightening forces with background supportCylinder heades, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngforces AG. Volkswagen AGTightening does agen ksw not l o gu yV ara db nte ise r o eo th u ra a c s sility ab y li an pt cerrectness of i t to the co nf o r m spec atio h re n in witS371_352 S371_354 Edge pressure supported by sturdy structure of cylinder head gasketHigh edge pressure leads to bending of cylinder headThe outer cylinder head bolts generate higher tightening forces due to the smaller contact surface of the cylinder head. This leads to greater pressure of the cylinder head gasket and thereby bending of the cylinder head. This bending subsequently causes distortion at the outer cylinder holes.With the background support, the greater edge pressure of the cylinder head gasket is brought under control so the cylinder head is bent less. Thanks to this improvement, the tightening force distribution at the outer combustion chamber stoppers has been optimised. In addition, overall movement of the cylinder head during engine operation has been reduced.thi sd o cu m enht rig py Co t.agen lksw Vo byAG.Prote cted by c o py rig ht . C op yi13Engine mechanicsThe toothed belt driveDriven via the toothed belt are the camshaft, the coolant pump and the high pressure pump for the common rail injection system.StabiliserDrive sprocket for camshaftDrive sprocket for high pressure pumpes, in part or in w l purpos hole ercia , is n m ot compe rm itte dToothed belt tensionerun leAG. Volkswagen AG d agen oes ksw not l o V gu y b ara d nte ise r o eo h t u ra a c s sCoolant pumpS371_078ility ab y li an pt ceCrankshaftrrectness of i t to the co nform spec a t i h re o n in wit thi sToothed beltr te o iva r rp fo g nCompared with the previous engine with distributor-type injection pump, the resistance to wear of the toothed belt has been markedly improved. The 26mm broad toothed belt features a polyamide material backing, which reduces wear of the toothed belt edges. The tooth material is also polyamide with an added polytetrafluoroethylene (Teflon) wear guard.do c um enht rig py Co t.Tooth material polyamide and TeflonS371_18414AG.Basic material rubberagen lksw Vo byProte cted byc o p yri gh t. C op yiBacking material polyamideTensioning cords glass fibreAncillary equipment driveThe ancillary equipment is driven by the crankshaft via a poly V-belt. The poly V-belt is held under constant pretension by means of a hydraulic tensioning system and is maintenancefree. In the belt drive system, the radiator fan, the steering assistance pump and the alternator are driven via the poly V-belt. There is also an option for an air conditioning compressor or second alternator to be integrated in this belt drive system.Belt drive Radiator fanSteering pumpAlternator Hydraulic tensioning element Poly V-belt Crankshaft S371_062 AG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte s i r Belt drive with air conditioner compressor Belt drive with 2nd o ealternator h or ut ac a s ses, in part or in w l purpos hole ercia , is n m ot p om c r erm o e t a itte riv du p or nl f e g nility ab y li an pt cerrectness of i t to the co nform spec at i h re o n wit in t hisS371_064Air conditioner compressor2nd alternatordo c um enS371_066ht rig py Co t.agen lksw Vo byAG.Prote cted by c o py rig h t . Co py i15Engine mechanicsAdditional ancillary equipmentAG. Volkswagen AG d agen oes ksw not l o gu yV b ar d e nte unit. If required, As an option, drive of the ancillary equipment can drive is also be extended by a further ancillary a r o e h ut r a belt pulley of a refrigerant compressor for a body with cooling system or a hydraulic pump can be driven byothe a c s sility ab y li an pt cethe vibration damper via an additional poly V-belt.es, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngrrectness of i t to the co nf o r m spec atio h re n in witBelt drive with ancillary drive for refrigerant compressorBelt drive with ancillary drive for hydraulic pumpthi sd o cu m enBelt pulleyS371_068Refrigerant compressorS371_070Belt drive with air conditioner compressor and ancillary drive for refrigerant compressorBelt drive with air conditioner compressor and ancillary drive for hydraulic pumpAir conditioner compressor Refrigerant compressorS371_072Hydraulic pump16ht rig py Co t.agen lksw Vo byAG.Prote cted by c o py rig h t . Co py iPoly V-beltHydraulic pumpAir conditioner compressor S371_074The oil circuitOil pressure is generated as on the previous engine by a self-priming crescent pump. It is bolted to the front of the cylinder block and is driven directly by the crankshaft. The pressure relief valve prevents components from becoming damaged as a result of excessive oil pressure. In the event of a blocked oil filter, the by-pass valve opens and thereby safeguards oil supply to the engine. The oil pressure retension valve assures lubrication of the valve drive.1312 14 15AG. Volkswagen AG d agen oes ksw no l o yV 8 t gua b d ran e tee ris ho t or u ac a ss15ility ab y li an pt ce11urposes, in part or in wh ole, cial p is n mer m ot p o c erm or e t a itte v i r d pun lerrectne s s o f i t to the co n form spec atio h re n wit i n thi sd o c um en71069 15 3 4512ht rig py Co t.Prote cted by c o py rig h t . Co py ir fo ngS371_324Key 1 2 3 4 5 6 7 8 -agen lksw Vo byAG.Oil sump Oil level and oil temperature sender G266 Oil pump Oil pressure relief valve Oil cooler By-pass valve Oil filter Oil pressure retension valve9 10 11 12 13 14 15 -Oil pressure switch F1 Crankshaft Spray jets for piston cooling Camshaft Vacuum pump Turbocharger Oil return17Engine mechanicsThe crankcase breatherCleaned air to intake portCyclonic oil separatorCycloneOilpe rm itte dun le. Volkswagen AG gen AG does Calming swa kchamber not l o gu yV b aracover Cylinder head d e nte is r o eo th u ra a c s sBlow-by gasesS371_005es, in part or in w l purpos hole ercia , is n m ot comOn internal combustion engines, pressure differences between the combustion chamber and crankcase cause air to flow between the piston rings and the cylinder path, otherwise known as blow-by gases. To avoid placing undue strain on the environment, these oil-rich gases are recirculated back to the intake area via the crankcase breather.On the cylinder head cover there is a cyclonic oil separator. It separates the oil contained in the gases from the air. The oil is fed back to the oil sump via a channel in the crankcase.rrectness of i t to the co nform spec a t i h re o n in wit thi sility ab y li an pt cer te o iva r rp fo g ndo c um en18ht rig py Co t.agen lksw Vo byAG.Prote cted by c o py rig ht . C op yiCoarse separationThe blow-by gases make their way from the crankshaft and camshaft area into a calming chamber. This is integrated in the cylinder head cover. In the calming chamber, larger droplets of oil are separated onto the walls and then collect on the floor. The oil can then drop into the cylinder head via the openings of the calming chamber.Fine separationWhen the engine is stationary, a reed valve opens Fine separation is carried out via a cyclonic oil that is closed when the engine is running by higher separator, which consists of three cyclones. Due to pressure in the cylinder head. the shape of the cyclones, the air is caused to rotate. k s l w The oil makes its way from the collection chamber The centrifugal force that is caused as a result forces o a V g . en AG gen AG does swa k n l o o the atomised oil against t gu back to the oil sump via the cylinder head. y V the separator wall. The oil ara db nte ise droplets are separated on the housing wall of the r o eo th u ra a cyclonic oil separator and are collected in a c s s collection chamber.ility ab y li an pt ceurposes, in part or in wh ole, cial p is n mer m ot p o c erm or e t a itte v i r d pun lerrectne s s o f i t to the co n form spec atio h re n wit i n thi sd o c um enCyclonic oil separator during engine operation Cleaned air to intake portCyclonic oil separator when engine is stationaryr fo ngCycloneht rig py Co t.Oil Collection chamber S371_272 Blow-by gases Reed valve closed S371_274 Reed valve openagen lksw Vo byAG.Prote cted by c o py rig ht . C op yi19Engine mechanicsPressure control valveThe pressure control valve can be found in the cover of the cyclonic oil separator. It comprises of a diaphragm and a spring and controls the pressure for ventilation of the crankcase. On induction of blow-by gases, the pressure control valve restricts vacuum in the crankcase. If vacuum pressure is too great in the crankcase, the engine gaskets and seals could become damaged.urposes, in part or in wh ole, cial p is n mer m ot p o c erm or e t a itte v i r d pun lePressure control valve open DiaphragmAG. Volkswagen AG d agen oes ksw not l o V gu y b ara d nte ise r o eo h t u ra a c s sPressure control valv closed Diaphragmility ab y li an pt ceSpringSpringrrectne s s o f i t to the co n form spec atio h re n wit i n thi sd o c um enTo intake portS371_281S371_283r fo ng20ht rig py Co t.If vacuum pressure is low in the intake port the valve opens by spring pressure.If vacuum pressure is great in the intake port the pressure control valve closes.agen lksw Vo byAG.Prote cted byc o p yri gh t. C op yiThe coolant circuites, in part or in w l purpos hole ercia , is n m ot p om c r erm o e t a itte riv du p or nl f e g nn AG. Volkswagen AG do es n wage s k l ot g o yV ua b ran ed s i tee r o h t or u ac a ssIn the coolant circuit the coolant is circulated by a mechanical coolant pump. It is driven by the toothed belt. The circuit is controlled by an expansion thermostat. An electric pump, the pump for coolant run-on, serves to circulate the coolant for the enhanced features of residual heat utilisation and coolant run-on.rrectness of i t to the co nform spec at i h re o n wit in t hisility ab y li an pt ce987do c um en6 52 3 4Key 1 2 3 4 5 6 Radiator for engine coolant circuit Coolant regulator/thermostat Coolant pump Oil cooler Exhaust gas recirculation cooler Coolant temperature sender G62 7 8 9 10 11 Coolant circulation pump V50 Heat exchanger for heater Expansion tank Vacuum valve for coolant run-on Coolant circuit valve N214ht rig py Co t.agen lksw Vo byAG.Prote cted byc o p yri gh t . C op yi10111S371_32221Engine mechanicsFunctions of coolant circuites, in part or in w l purpos hole ercia , is n m ot compe rm itte dun leAG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte is r o eo h ut ra a c s sility ab y li an pt cerrectness of i t to the co nform spec a t i h re o n in wit thi sTo warm up the engine quickly the thermostat [2] is closed and thereby seals return from the radiator [1]. At a coolant temperature from approx. 87°C the thermostat opens the large coolant circuit via the radiator. The coolant temperature is transmitted by the coolant temperature sender G62 [6] to the engine control unit.6r te o iva r rp fo g n21do c um enEnhanced features of coolant circuitIn addition to cooling the engine and the provision of heat for the vehicle heater, the cooling circuit has additional functions.Residual heat utilisationResidual heat utilisation makes it possible for the desired temperature in the passenger compartment to be maintained even when the engine is switched off. This is possible providing the coolant temperature is sufficiently high enough.Function For the residual heat function, the coolant circulation pump V50 [7] is actuated by the engine control unit in order to maintain the volumetric flow in the coolant circuit. If there is no longer enough residual heat, the air conditioning control unit switches the residual heat function off.S371_35822ht rig py Co t.agen lksw Vo byAG.Prote cted by c o py rig h t . Co py iS371_3567Coolant run-onThe coolant run-on is a protective system for the engine. It prevents vapour locks forming in areas of the cylinder head when the engine is switched off. The function becomes active if the coolant temperature is more than 105°C after the engine has been switched off and the vehicle was driven in the previous driving cycle with a respectively high load.7101es, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngAG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte is r 11 o eo h Function ut ra a c s sS371_360For the function of the coolant run-on, the coolant circulation pump V50 [7] and the coolant circuit valve N214 [11] are actuated by the engine control unit. The coolant circuit valve N214 opens the coolant run-on vacuum valve [10]. In this way, cold water from the radiator [1] is added to the circuit. The cylinder head is thus cooled equally and quickly and vapour lock is avoided.ility ab y li an pt cerrectness of i t to the co nf o r m spec atio h re n in witthi sd o cu m enht rig py Co t.agen lksw Vo byAG.Prote cted by c o py rig h t . Co py i23Engine mechanicsCoolant run-on vacuum valveThe coolant run-on vacuum valve is a mechanicalpneumatic valve. It is switched to the OPEN and CLOSED position by the coolant circuit valve N214 by vacuum pressure. When unenergised, the vacuum valve is open. When the engine is running, it is closed by the engine control unit via the coolant circuit valve N214. To utilise the residual heat function when the engine is switched off, the vacuum valve is held closed by a non-return valve in the vacuum system.S371_042urposes, in part or in wh ole, cial p is n mer m ot p o c erm or e t a itte v i r d pun leAG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte is r o eo h ut ra a c s sA defective vacuum valve or a defect in the associated vacuum system can lead to poor heater output and higher emissions of harmful substances during the starting and warm-up phase, particularly in winter. Because in this case cold water is still added to the heating circuit, despite the thermostat being closed, the engine has an insufficient warm-up phase. Furthermore, a poor residual heat output can be an indication of a defect in the vacuum valve or the associated vacuum system.ility ab y li an pt cerrectne s s o f i t to the co n form spec atio h re n wit i n thi sd o c um enS371_196r fo ng24ht rig py Co t.agen lksw Vo byAG.Prote cted by c o py rig h t . Co py iCoolant circulation pump V50The coolant circulation pump is an electrically driven pump that, when required, is actuated via the coolant run-on relay J151 by the engine control unit or the air conditioning control unit. It fulfils the following roles:●To support passenger compartment heating, the coolant circulation pump provides sufficient circulation of the coolant in the heating circuit. For the residual heat utilisation and coolant run-on functions, the pump assures recirculation of the coolant in the cooling circuit.S371_026●Coolant circuit valve N214es, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngAG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte is r o eo th u ra a c s sThe coolant circuit valve is an electro-pneumatic valve and can be found in the engine compartment above the right-hand vehicle side member. It switches the vacuum to actuate the vacuum valve for coolant run-on. Effects of failure In the event of failure of the coolant circuit valve, the vacuum valve for coolant run-on cannot be closed after the engine has been started. This can lead to poor heater output during the start and warm-up phase and an increase in harmful emissions. Since in this case cold water is still added to the heater circuit despite the thermostat being closed, the engine has an insufficient warm-up phase.ht rig py Co t.ility ab y li an pt cerrectness of i t to the co nf o r m spec atio h re n in witthi sd o cu m enS371_304agen lksw Vo byAG.Prote cted by c o py rig ht . C op yi25Engine mechanicsThe fuel systemFuel supply pump G [2] Continually delivers fuel to supply system.es, in part or in w l purpos hole ercia , is n m ot compe rm itte dun leAG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte is r o eo th u ra a c s sility ab y li an pt ce5rrectness of i t to the co nform spec a t i h re o n in wit thi sFuel filter heater Z57 [4] Protects the filter from crystallising paraffins at low ambient temperatures.6Fuel temperature sender G81 [6] Measutres the current fuel temperature.7 98r te o iva r rp fo g nMechanical gear-type pump [7] Delivers fuel from supply system to the high pressure pump.do c um enFuel metering valve N290 [9] Regulates the amount of fuel to be compressed based on requirement.3 2Fuel pressure control valve N276 [10] Regulates the fuel pressure in the high pressure range.Key 1 2 3 4 5 6 7 8 9 Fuel tank Electric fuel pump G6 Fuel filter Fuel filter heater Z 57 Fuel accumulator Fuel temperature sender G81 Mechanical gear-type pump High pressure pump Fuel metering valve N290High pressure accumulator (rail) [11] Stores the fuel for all cylinders under high pressure as required for injection.26AG.4agen lksw Vo byHigh pressure pump [8] Generates high fuel pressure necessary for injection.ht rig py Co t.Prote cted by c o py rig ht . C op yi17 161Fuel pressure sender G247 [12] Measures the current fuel pressure in the high pressure range1015 1112Pressure retension valve [14]pe rm itte dun leMaintains the return pressure from the injectors AG. Volkswagen A G do agen es n ksw l o o t gu at approx. 10bar. This pressure is required for 15 yV ara db ntfunction. ise r the injectors to ee o th or u ac a s s Restrictors [15] Dampen pressure waves in the high pressure system that are caused during the injection sequence by opening and closing of the nozzles.rrectness of i t to the co nform spec a t i h re o n in wit thi sility ab y li an pt cees, in part or in w l purpos hole ercia , is n m ot com1413S371_116Colour coding/keyHigh pressure 230 – 1600barOverflow [16] Thanks to the overflow from the fuel supply to the fuel return, the fuel pressure is regulated before the filter. When the delivery volume is high from the fuel supply pump G6, the fuel can flow back in the tank via the overflow.Supply pressure / return pressurer te o iva r rp fo g nReturn pressure from injectors 10barNon-return valve [17] Prevents fuel from entering the fuel system from the fuel supply pump G6 via the return, for example if the fuel filter is blocked.ht rig py Co t.do c um en10 11 12 13 14 15 16 17 -Fuel pressure control valve N276 High pressure accumulator (rail) Fuel pressure sender G247 Injectors N30, N31, N32, N33, N83 Pressure retension valve Restrictors Overflow Non-return valveagen lksw Vo byAG.Prote cted by c o py rig ht . C op yi27Engine mechanicsFuel filterThe fuel filter protects the injection system from contamination and wear from particles and water. Integrated in the fuel filter is an electric heater. This heats up the fuel in the filter at low ambient temperatures. In this way, action is taken to prevent crystallising paraffins building up in the fuel filter at low ambient temperatures.Aluminium plates Electrical connectionBi-metalS371_326Fuel filter heater Z51The fuel filter heater Z51 comprises of two aluminium plates and a bi-metal contact switch.AG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte to +8°C the biAt warm temperatures, the bi-metal contact switch At a temperature of approx. +3°C isis r o eo th u ra in a state of rest. The electric contact is open. In this metal contact closes. The fuel filter heater is energised a c s sility ab y li an pt cees, in part or in w l purpos hole ercia , is n m ot p om c r erm o e t a itte riv du p or nl f e g nway, no current flows to activate the fuel filter heater.and the fuel is heated up by the aluminium plates in the fuel filter.rrectness of i t to the co nform spec at i h re o n wit in t hisHeater offHeater on Contact closedContact open FuelBi-metalBi-metal31 1531 15Electrical connectionht rig py Co t.do c um enS371_29228AG.Filter elementUnenergised aluminium platesagen lksw Vo byProte cted by c o py rig ht . C op yiEnergised aluminium platesS371_290Fuel accumulatorpe rm itte dun leAG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte is r o eo th u ra a c s ses, in part or in w l purpos hole ercia , is n m ot comThe fuel accumulator is located on the engine above the exhaust manifold. It assures that the fuel pressure before the gear-type pump is near enough the same in all operating conditions. The constant pressure level means that a good starting and idling response is achieved.rrectness of i t to the co nform spec a t i h re o n in wit thi sility ab y li an pt ceFunctionr te o iva r rp fo g nThe fuel delivered by the fuel supply pump G6 is fed to the fuel accumulator. From there is makes its way to the gear-type pump. To balance out pressure deviations, the excess fuel in the fuel accumulator is fed back into the fuel return system.do c um en4Return from rail6 5Return from injectors3 2 Key 1 2 3 4 5 6 Fuel tank Fuel supply pump G6 Fuel filter Fuel accumulator Mechanical gear-type pump High pressure pump1 S371_316 Return to fuel tankS371_172 Supply to high pressure pumpAG.Supply to railagen lksw Vo byS371_024The fuel return from the high pressure pump and the high pressure accumulator (rail) is fed in the fuel supply to the fuel accumulator. In the fuel accumulator, the warm fuel from the high pressure pump and the rail mixes with the cold fuel from the fuel supply. This results in the fuel heating up quickly in cold weather conditions and thereby for a good warm-up response of the engine.ht rig py Co t.Prote cted by c o py rig ht . C op yiReturn from high pressure pump and rail + supply from fuel filter29Engine mechanicsThe common rail injection systemAll 2.5 l TDI engines in the Crafter are equipped with a common rail injection system. This is a high pressure accumulator injection system for diesel engines. The term “common rail” means that the high fuel pressure accumulator or rail is common for all the injectors of one cylinder bank. Pressure generation and fuel injection are separated from each other on this injection system. A separate high pressure pump generates the high pressure necessary for injection. It is stored or accumulated in a high pressure accumulator (rail) and makes its way via short injector lines to the injectors. The injection system is regulated by the Bosch EDC 16 C engine management system.Fuel pressure control valve N276 Fuel pressure sender G247High pressure pumpun len AG. Volkswagen AG do es n wage s k l ot g o Injectors yV ua b ran N32, N33, N83 ed N30, N31, s i tee r o h t or u ac a ssility ab y li an pt ceurposes, in part or in wh ole, cial p is n mer m ot p o c erm or e t a itte v i r d pFuel metering valve N290S371_118The properties of this injection system are:●●●● ● ●The injection pressure is able to be selected practically without restriction and can be adapted to the relevant operating status of the engine. A high injection pressure of up to maximum 1600bar allows good mixture formation. A flexible injection pattern with several pilot and post injections Low fuel consumption Low harmful emissions Smooth engine runningr fo ngThe common rail injection system offers many means of configuration to adapt the injection pressure and the injection sequence to the operating status of the engine.In this way, it is well setup to meet the rising demands on an injection system for low fuel consumption, low harmful emissions and smooth engine running.rrectne s s o f i t to the co n form spec atio h re n wit i n thi sd o c um enThe principle of operation of the common rail injection system with piezo injectors is described in selfstudy programme SSP 351 “The common rail injection system of the V6 TDI engine”.AG.30ht rig py Co t.agen lksw Vo byProte cted byc o p yri gh t . C op yiInjectorsun len AG. Volkswagen AG do es n wage s k l ot g o yV ua b ran ed s i tee r o h t or u In the common rail ac a ssurposes, in part or in wh ole, cial p is n mer m ot p o c erm or e t a itte v i r d pFuel supply (high pressure connection)system of the 2.5 l TDI engine in the Crafter, piezo controlled injectors are used. The injectors are controlled by a piezo actuator. The switching speed of a piezo actuator is roughly four times faster than a solenoid valve. In addition, the piezo technology has about 75% less moving mass at the injector needle compared with solenoid valve controlled injectors. The advantages are as follows:ility ab y li an pt cerrectne s s o f i t to the co n form spec atio h re n wit i n thi sd o c um enPiezo actuator● ● ●Very short switching times Option of multiple injections per working cycle Precisely metered injection quantitiesr fo ngInjector needle S371_383Injection sequenceDue to the very short switching times of the piezo controlled injectors, it is possible to control the injection phases and injection quantities flexibly and precisely. In this way, the injection sequence can be adapted to the relevant demands for the operating conditions of the engine. Up to five part injections can be carried out per injection sequence.Actuation voltage (volts)Injection (injection rate)S371_384 Pilot injection Main injection Post injection Post injectionht rig py Co t.agen lksw Vo byAG.Prote cted byc o p yri gh t . C op yiTime31Engine mechanicsControl of high fuel pressureOn the common rail injection system in the Crafter, the high fuel pressure is controlled by a so-called dual regulator concept. Depending on the operating condition of the engine, the high fuel pressure is controlled either by the fuel pressure control valve N276 or the fuel metering valve N290. To do this, the valves are actuated by the engine control unit with a pulse width modulated signal (PWM signal).es, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngn AG. Volkswagen AG do es n wage ot g ua d ran e s i tee r o h or ut fuel pressure control valve N276 ac a Regulation by ssks Dual regulator concept Vol byWhen the engine starts and to warm-up the fuel, the high fuel pressure is regulated by fuel pressure control valve N276. For good mixture formation in the combustion chamber with short ignition delays, a high fuel temperature is necessary. To heat the fuel up quickly on a cold engine, more fuel is delivered and compressed by the high pressure pump than necessary. The excess fuel is fed back into the fuel return system by the fuel pressure control valve N276.rrectness of i t to the co nf o r m spec atio h re n in witility ab y li an pt ceRegulation by fuel metering valve N290At high injection quantities and high rail pressures, the high fuel pressure is regulated by the fuel metering valve. In this way, there is a demand-based regulation of the high fuel pressure. The output of the high pressure pump is reduced and any unnecessary heating of the fuel is avoided.thi sd o cu m enInjection quantityS371_174Speed32ht rig py Co t.agen lksw Vo byAG.Prote cted byc o p yri gh t. C op yiRegulation of high fuel pressure by fuel pressure control valve N276 Regulation of high fuel pressure by fuel metering valve N290The diesel particulate filterTemperature sender before particulate filter G506 Pressure sensor 1 for exhaust gas G450Lambda probe G39Diesel particulate filterTemperature sender after particulate filter G527 S371_382AG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e Since the operating temperature of To achieve the EURO 4 and EU4 emissions standard, nte is r o eo h t r a reached quickly, particulate filter is a catalytic coated diesel particulate filter is installed au c sses, in part or in w l purpos hole ercia , is n m ot comas standard in close vicinity to the engine. On this particulate filter system, the diesel particulate filter is joined together to form one module with the oxidising catalyst. For this reason and due to the fact that the installation position is close to the engine, the use of an additive is not necessary.pe rm itte dthe diesel a continual, passive regeneration is possible. Active regeneration by the engine control unit is carried out when the particulate filter is full of soot particles, for example after short part load journeys. In this case, the soot particles are burnt off by a targeted increase in the exhaust gas temperature.ility ab y li an pt ceun ler te o iva r rp fo g nThe principle of operation of the diesel particulate filter is described in self-study programme SSP 336 “The catalytic coated diesel particulate filter”.do c um enrrectness of i t to the co nform spec a t i h re o n in wit thi sht rig py Co t.agen lksw Vo byAG.Prote cted by c o py rig h t . Co py i33System overviewSensorsG28 Engine speed senderAG. Volkswagen AG d agen oes ksw not l o V gu y b ara d nte ise r o eo h t u ra a c s sG79Gas pedal position senderes, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngG40Hall senderDiagnosis connectionility ab y li an pt cerrectness of i t to the co nf o r m spec atio h re n in witG70Air mass meterG62 G31 G42Coolant temperature sender Charge pressure sender Intake air temperature senderJ623 Engine control unitG71Intake manifold pressure senderthi sd o cu m enG81Fuel temperature senderG247 Fuel pressure sender G212 Potentiometer for exhaust gas recirculationG39Lambda probeG450 Pressure sensor 1 for exhaust gasG235 Exhaust gas temperature sender 1 CAN powertrain data busG506 Temperature sender before particulate filter G527 Temperature sender after particulate filterF F36Brake light switch Clutch pedal switchF379 Clutch pedal switch 2F365 Switch for gearbox neutral positionE101Main switch for stop/start systemG266 Oil level and oil temperature sender34ht rig py Co t.agen lksw Vo byAG.Prote cted byc o p yri gh t. C op yiActuatorsJ17 G6 Fuel pump relay Fuel supply pumpN30 N31 N32 N33 N83Injector for cylinder 1 Injector for cylinder 2 Injector for cylinder 3 Injector for cylinder 4 Injector for cylinder 5N290 Fuel metering valveN276 Fuel pressure control valveN75 Charge pressure control solenoid valven AG. Volkswagen AG do es n wage s k l ot g o yV ua b ran ed s i tee r V157 Intake manifold flap motor o h t or u ac a ssility ab y li an pt cees, in part or in w l purpos hole ercia , is n m ot p om c r erm o e t a itte riv du p or nl f e g nN18Exhaust gas recirculation valverrectness of i t to the co nform spec at i h re o n wit in t hisJ285 Control unit in dash panel insertN345 Changeover valve for exhaust gas recirculation coolerJ151 Continued coolant circulation relay V50 Coolant circulation pumpN214 Coolant circuit valvedo c um enZ19Lambda probe heaterht rig py Co t.S371_328agen lksw Vo byAG.Prote cted byc o p yri gh t . C op yiJ179 Q10 Q11 Q12 Q13 Q14Automatic glow period control unit Glow plug 1 Glow plug 2 Glow plug 3 Glow plug 4 Glow plug 535Engine managementCharge pressure control9 1 24un le3 5 6es, in part or in w l purpos hole ercia , is n m ot compe rm itte dKey 1 - Vacuum system 2 - Engine control unit J623 olkswagen AG 3 Intake air n AG. V ge does swa k not l o V 4 - Charge air cooler gu y ara db e 5 Charge pressure control solenoid N75 nvalve is tee r o h t o 6 Compressor of turbocharger ra au c ss 7 - Vacuum unit 8 - Exhaust turbine with guide vane adjustment 9 - Charge pressure sender G31/intake air temperature sender G42ility ab y li an pt cerrectness of i t to the co nform spec a t i h re o n in wit thi s7 8S371_230r te o iva r rp fo g nThe charge pressure control regulates the quantity of air that is compressed by the turbocharger. The turbocharger increases the pressure during the intake stroke of the engine so that a greater amount of air makes its way into the cylinder during intake. This means that there is more oxygen available for combustion of a respectively larger fuel quantity. The result is an increase in power with the same engine speed.An increase in power is also achieved by the use of a charge air cooler. The combustion air drawn in via the air cleaner heats up significantly on its way to the engine, particularly in the turbocharger. The density of air and thereby the amount of oxygen available for combustion becomes less. The air is cooled down again in the charge air cooler. The air density is thereby increased again. Following this stage, the air is forced into the combustion chamber.ht rig py Co t.do c um en36agen lksw Vo byAG.Prote cted by c o py rig h t . Co py iCharge pressure sender G31/ intake air temperature sender G42The charge pressure sender G31 and the intake air temperature sender G42 are integrated as one component and can be found in the intake manifold.S371_300Charge pressure sender G31Signal application The current air pressure in the intake manifold is determined from the signal of the charge pressure sender. The engine control unit requires the signal to control the charge pressure.Intake air temperature sender G42n AG. Volkswagen AG do es n wage s k l ot g Vo y ua b The e signal of the intake air temperature sender d ran uses s i tee r o h engine control unit for regulation of the charge the t or u ac a ss pressure. Since the temperature influences the densitySignal applicationility ab y li an pt cees, in part or in w l purpos hole ercia , is n m ot p om c r erm o e t a itte riv du p or nl f e g nof the charge air, the signal is used as a correction variable by the engine control unit.rrectness of i t to the co nform spec at i h re o n wit in t hisEffects of failureIn the event of failure of the signal, there is no substitute function. The charge pressure control is switched off and the engine output is reduced.do c um enht rig py Co t.agen lksw Vo byAG.Prote cted byc o p yri gh t . C op yi37Engine managementExhaust gas turbochargerThe charge pressure is generated on the 2.5 l TDI engine in the Crafter by an adjustable turbocharger. It features adjustable guide vanes through which the exhaust flow can influence the turbine rotor. The advantage of this is that an optimal charge pressure can be achieved across the whole speed AG. Volkswagen AG do n es n wage range and thereby good combustion. TheVadjustable ot g olks y ua b d and good ran e guide vanes allow a high level of torque tee ris o h t or drive-off response in the lower s speed range. In the ac au s higher speed range, the advantage is low fuel consumption and low exhaust emissions. The guide vanes are adjusted by vacuum pressure via a linkage.es, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngThe principle of operation of the adjustable turbocharger is explained in self-study programme SSP 190 “Adjustable turbocharger”.ility ab y li an pt ceS371_122rrectness of i t to the co nf o r m spec atio h re n in witCharge pressure control solenoid valve N75The solenoid valve for charge pressure control is an electro-pneumatic valve. It can be found in the engine compartment above the right-hand vehicle side member. The solenoid valve controls the vacuum pressure, which is required to adjust the guide vanes via the vacuum unit. Effects of failure In the effect of failure of the solenoid valve, the vacuum unit is not supplied with vacuum pressure. A spring in the vacuum unit moves the linkage of the adjusting mechanism so that the guide vanes of the turbocharger are moved to a steep setting angle (emergency position). At low engine speed and thereby low exhaust gas pressure, there is only a low amount of charge pressure. The engine has less power.Prote cted by c o py rig h t . Co py ithi sd o cu m en38ht rig py Co t.agen lksw Vo byAG.S371_306Exhaust gas recirculationun lepe rm itte dAG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte is r o eo th u ra a c s sility ab y li an pt cees, in part or in w l purpos hole ercia , is n m ot comExhaust gas recirculation is a measure to reduce the amount of nitrogen oxide emissions. Thanks to exhaust gas recirculation, part of the exhaust gases are recirculated into the combustion process.To do this, the oxygen content of the fuel and air mixture is reduced, which results in slowing down of combustion. In this way, the combustion peak temperature falls and the nitrogen emissions are reduced.rrectness of i t to the co nform spec a t i h re o n in wit thi s1 2 4r te o iva r rp fo g n3756agen lksw Vo by8AG.9Key 1 - Intake air 2 - Intake manifold flap with intake manifold flap position sender and intake manifold flap motor V157 3 - Exhaust gas recirculation valve with exhaust gas recirculation potentiometer G212 and exhaust gas recirculation valve N18 4 - Engine control unit J623 5 - Exhaust gas supply line 6 - Coolant temperature sender G62 7 - Lambda probe G39 8 - Exhaust manifold 9 - Exhaust gas turbocharger 10 - Exhaust gas cooler 11 - Changeover valve for exhaust gas recirculation cooler N345do c um en1011S371_232The exhaust gas recirculation quantity is controlled by a map in the engine control unit via the exhaust gas recirculation valve. The exhaust gas recirculation quantity is generally dependent on the engine speed, the injection quantity, the air mass drawn in, the intake air temperature and the air pressure. A broadband lambda probe is located in the exhaust gas stream before the particulate filter. With the lambda probe, the amount of oxygen in the exhaust gas can be determined across a wide measuring range.ht rig py Co t.Prote cted by c o py rig ht . C op yiThe signal from the lambda probe is used as a correction variable for the exhaust gas recirculation system to control the amount of recirculated exhaust gas. If the oxygen content in the exhaust gas deviates from the specification of the exhaust gas recirculation map, the engine control unit actuates the exhaust gas recirculation valve N18 and alters the amount of exhaust gas to be recirculated respectively. An exhaust gas recirculation cooler cools the recirculated gases to reduce the combustion temperature. This assures that a larger amount of exhaust gases can be recirculated.39Engine managementExhaust gas recirculation valveOn the 2.5 l TDI engine in the Crafter there is an electrically actuated exhaust gas recirculation valve. It comprises of exhaust gas recirculation valve N18 and exhaust gas recirculation potentiometer G212 and is seated in the direction of flow in the inlet of the intake manifold. The electrically actuated exhaust gas recirculation valve allows infinitely variable and thereby precise regulation of the recirculated exhaust gases.S371_040Exhaust gas recirculation valve N18Design Effects of failurees, in part or in w l purpos hole ercia , is n m ot p om c r erm o e t a itte riv du p or nl f e g nIn the event of failure of the exhaust gas recirculation Exhaust gas recirculation valve N18 is a valve with an ag Volksw en AG by the valve spring. AG.valve n valve N18, the is closed electric motor for actuation. It can be adjusted with does wage s k not l o V gu y exhaust gas can be recirculated. No the electric motor with infinite variability. To do this, b ara d e nte ris o the rotational movement of the electric motor is eo h t u ra a c converted into a lift motion via an eccentric and a ss guide plate. The quantity of recirculated exhaust gas is controlled by the amount of valve lift.ility ab y li an pt cerrectness of i t to the co nform spec at i h re o n wit in t hisExhaust gas recirculation valve closedExhaust gas recirculation valve open Potentiometer for exhaust gas recirculation G212Electrical connectionElectric motorEccentric Guide plateht rig py Co t.do c um enValve spring ValveS371_242Exhaust gas recirculation inlet40agen lksw Vo byAG.Prote cted byc o p yri gh t . C op yiS371_244Potentiometer for exhaust gases, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngn AG. Volkswagen AG do es n wage s k l ot g o yV ua b ran ed s i tee r o h t or u recirculation G212 ac a ssHall senderMagnetThe potentiometer for exhaust gas recirculation picks up the position of the valve head in the exhaust gas recirculation valve. The amount of valve lift controls the flow of recirculated exhaust gas in the intake manifold.rrectness of i t to the co nf o r m spec atio h re n in witility ab y li an pt ceDesignGuide plate S371_246The sender is integrated in the cover of the exhaust gas recirculation valve. It comprises of a Hall sender and a permanent magnet, which is moved up and down by the valve head via the guide plate. The movement of the magnet is picked up without contact by the Hall sender. The change in field strength allows the opening stroke of the valve head to be calculated.thi sd o cu m enSignal application Using the signal, the engine control unit can detect the current position of the valve head. The quantity of recirculated exhaust gas and thereby the nitrogen oxide content in the exhaust gas is controlled with this data.Effects of failure In the event of failure of the sensor, the exhaust gas recirculation feature is switched off. Drive for the exhaust gas recirculation valve is switched to unenergised and the valve head is closed by the valve spring.The principle of operation of the Hall sensor in the potentiometer for exhaust gas recirculation is described on page 52 in this self-study programme.ht rig py Co t.agen lksw Vo byAG.Prote cted byc o p yri gh t . C op yi41Engine managementExhaust gas recirculation coolerThe cooler for exhaust gas recirculation cools the recirculated exhaust gases. In this way, the combustion temperature is reduced in addition and a greater amount of exhaust gases can be recirculated. On the engine versions with emissions standard EU4, a switchable exhaust gas recirculation cooler is used. In this way, the engine and the diesel particulate filter reach their operating temperatures faster. The exhaust gas is not cooled until the operating temperature has been reached.es, in part or in w l purpos hole ercia , is n m ot p om c r erm o e t a itte riv du p or nl f e g nAG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte is r o eo h ut ra a c s sility ab y li an pt cerrectness of i t to the co nform spec at i h re o n wit in t hisS371_216DesignCoolant connectionCooling channelsCoolant connectiondo c um enPipe housingBypass channel S371_21842ht rig py Co t.agen lksw Vo byAG.Prote cted by c o py rig h t . Co py iSelector guideFunctionExhaust gas cooling inactivees, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngAG. Volkswagen AG d agen oes ksw not l o V gu y b ara d nte ise r o h t At a coolant temperature below 34°C exhauste gas or u ac a ssrecirculation is switched off. The flap closes the cooling channels and the bypass channel is open. The exhaust gas is fed to the intake manifold without cooling.During cold starting of the engine, feeding uncooled exhaust gases into the system helps the engine and catalytic converter to reach operating temperature more quickly. For this reason, the cooler is closed until the switching conditions have been met.ility ab y li an pt cerrectness of i t to the co nf o r m spec atio h re n in witS371_240Flap seals cooling channels, bypass channel open.thi sd o cu m enVacuum unitBy the initiation of cooled exhaust gas, formation of nitrogen oxides in the combustion chamber is avoided, particularly at high combustion temperatures.S371_238 Flap closes bypass channel, cooling channels open.agen lksw Vo byExhaust gas cooling activeFrom a coolant temperature of 35°C the exhaust gas cooler is switched on by the flap closing the bypass channel. To do this, the engine control unit actuates the changeover valve for exhaust gas recirculation cooler N345. The recirculated exhaust gas now flows through the cooling channels.AG.Prote cted byht rig py Co t.c o p yri gh t. C op yi43Engine managementun leChangeover valve for exhaust gas recirculation cooler N345es, in part or in w l purpos hole ercia , is n m ot comAG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte is r o eo h ut ra a c s sility ab y li an pt ceThe changeover valve for exhaust gas recirculation is an electro-pneumatic valve. It can be found in the engine compartment above the right-hand vehicle side member and supplies the vacuum unit of the exhaust gas recirculation cooler with the vacuum pressure necessary for the switching process. Effects of failurepe rm itte drrectness of i t to the co nform spec a t i h re o n in wit thi sThe intake manifold flapIn the direction of flow before the exhaust gas recirculation valve is an electrically actuated intake manifold flap. Adjustment of the intake manifold flap is infinitely variable and can therefore be adapted to the respective load and speed of the engine.The intake manifold flap has the following tasks: - In certain operating conditions, the intake manifold flap generates a difference between the intake manifold pressure and exhaust gas pressure. As a result of this pressure difference, an effective exhaust gas recirculation is achieved. - In regeneration mode of the diesel particulate filter, the amount of air intake is regulated with the intake manifold flap. - When the engine is switched off, the flap is closed. In this way, less air is drawn in and compressed, which allows the engine to run down smoothly.44ht rig py Co t.agen lksw Vo byAG.Prote cted by c o py rig h t . Co py iIn the event of failure of the changeover valve, the bypass flap can no longer be actuated by the vacuum unit of the exhaust gas recirculation cooler. The bypass flap of the exhaust gas cooler remains open and the exhaust gas cooling feature thereby remains active. More time is therefore needed for the system to reach operating temperature.r te o iva r rp fo g nS371_302do c um enS371_038Intake manifold flap motor V157Electric motorThe intake manifold flap motor V157 is an electric motor that actuates the intake manifold flap via a gear mechanismEffects of failure In the event of failure, correct regulation of the exhaust gas recirculation rate is no longer possible. Active regeneration of the diesel particulate filter does not take place.S371_296pe rm itte dIntake manifold flap position senderes, in part or in w l purpos hole ercia , is n m ot comun leAG. Volkswagen AG d agen oes ksw not l o g yV b Gearbox Intake manifold uara d e nte is r eo flap tho u ra a c s sThe sensor element is integrated in the drive mechanism of the intake manifold flap. It picks up the current position of the intake manifold flap.rrectness of i t to the co nform spec a t i h re o n in wit thi sDesignr te o iva r rp fo g nS371_298The sensor can be found on a circuit board beneath the plastic cover of the intake manifold flap module. It is a magneto-resistive sensor that acts as a feeler on a permanent magnet on the axis of the control flap.Permanent magnetdo c um enility ab y li an pt ceMagneto-resistive sensorProte cted by c o py rig ht . C op yiSignal applicationWith the signal the engine control unit can detect the current position of the intake manifold flap. This information is required for control of the exhaust gas recirculation and particulate filter regeneration.AG.The principle of operation of the magneto-resistive sensors is described in self-study programme SSP 368 “The 2.0 l 125 kW TDI engine with 4-valve technology”.ht rig py Co t.Effects of failure In the event of failure, the exhaust gas recirculation is switched off and no regeneration of the diesel particulate filter takes place. An entry in the fault memory is made under the associated intake manifold flap motor V157.agen lksw Vo by45Engine managementThe preglow systemAG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte is r o eo th u ra a c s Advantages of the preglow system quick ses, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngThe 2.5 l TDI engine in the Crafter has a diesel start preglow system. It makes quick starting of the engine possible, similar to petrol engines, in all climatic conditions without waiting long periods for the glow plugs.- Start at temperatures down to minus 24°C like on petrol engines - Extremely fast warm-up time Up to 1000°C are reached at the glow plug within 2 seconds. - Controllable temperatures for preglow and afterglow - Capable of self-diagnosis - Part of Euro onboard diagnosis.ility ab y li an pt cerrectness of i t to the co nf o r m spec atio h re n in witthi sd o cu m enSystem overviewG28 Engine speed sender Q11 Glow plug 2 J179 Automatic glow period control unitG62 Coolant temperature sender Q12 Glow plug 3J519 Onboard supply control unitJ285 Control unit in dash panel insertK29 Control lamp for preglow period Q14 Glow plug 546AG.J623 Engine control unitht rig py Co t.agen lksw Vo byProte cted by c o py rig ht . C op yiQ10Glow plug 1Q13 Glow plug 4S371_388Automatic glow period control unit J179es, in part or in w l purpos hole ercia , is n m m ot p o c erm or e t a itte iv r du rp o nl f e ngAG. Volkswagen AG d agen oes ksw not l o gu yV b ara d e nte i