The 3.0 l V6 245kW TSI engine with supercharger in the Touareg Hybrid Design and Function

Transcription

1 Service Training Self-study Programme 452 The 3.0 l V6 245kW TSI engine with supercharger in the Touareg Hybrid Design and Function

2 The 3.0 l V6 engine with supercharger and hybrid drive sees Volkswagen employ a new drive concept. The engine is fitted in the Touareg Hybrid model year You will find further information in self-study programme SSP 450 The Touareg Hybrid. The engine has already been used at Audi without the hybrid combination. By incorporating new technology and combining the direct injection method, the resulting engine concept is extremely impressive in terms of compact design, acoustics, response and fuel consumption. The engine has very diverse characteristics. It is therefore suited to driving styles ranging from comfort-oriented to very sporty. The sporty configuration of the engine in particular is aimed at a special group of customers. The so-called take-off performance of the vehicle plays a major role here. The aim is to achieve the greatest possible acceleration between traffic lights in urban traffic. S452_002 Please note that only persons with technical training in electrics may work on the vehicle once the battery has been disconnected. The self-study programme portrays the design and function of new developments. The contents will not be updated. For current testing, adjustment and repair instructions, refer to the relevant After Sales literature. Important Note 2

3 Contents Introduction Engine Components Air Supply Cooling System Exhaust Gas Treatment Oil Supply Fuel System Engine Management Service Glossary explanation of HIGHLIGHTED terms Test Yourself

4 Introduction The 3.0 l V6 245kW TSI engine with supercharger Technical features of engine Six-cylinder V engine with mechanical supercharging Additional charge air cooler before main cooler Volumetric flow-controlled oil pump Demand regulated fuel system Intake manifold flaps Ultrasound oil level sensor Secondary air system for compliance with emissions laws Belt drive for supercharger Charger module with integrated charge-air cooling Camshaft adjustment only on intake side Electric drive motor V141, also called electric motor/generator The following components are electrically driven: Vacuum pump for brake servo (in addition to mechanical vacuum pump), power steering pump, air-conditioning compressor Charger module 2nd belt drive 1st belt drive S452_010 Superchargers are sometimes called charger modules or Roots blowers. Crankshaft drive 4

5 Torque output curve During kickdown, the drive power outputs from the combustion engine and electric motor are combined to deliver a total maximum power of 279kW. This means that the output curve is raised by the drive power figure of 34kW for the alternator. This occurs across almost the whole rev range. Torque (Nm) Torque increase from electric motor (Nm) Output (kw) Power increase from electric motor (kw) Technical data Engine speed (rpm) S452_011 Engine code CGEA Type 6-cylinder V engine Displacement 2,995 cm 3 Bore Stroke 84.5 mm 89 mm Valves per cylinder 4 Compression ratio 10.5:1 Maximum output 245kW at 5,500 to 6,500 rpm Firing order Maximum torque in petrol mode 440 Nm at 3,000 to 5,250 rpm Engine management Bosch MED Fuel Premium unleaded RON 95 Mixture formation Exhaust gas treatment Emissions standard Direct injection TSI (homogeneous) High-pressure fuel pump HDP 3 Cylinder bank-specific Lambda control with a broadband probe before catalytic converter for each cylinder bank, two ceramic catalytic converters with downstream transient Lambda probe (step-type Lambda probe) EU5 5

6 Introduction The history of superchargers at Volkswagen From a historical viewpoint, the use of mechanical supercharging in the form of a blower is not completely new to vehicles from the Volkswagen segment. A mechanical supercharger (G-Lader or G-supercharger) featured in the Polo G40 back in Versions of the Golf and Corrado using the G60 supercharger then followed in In 2006, the 1.4 l TSI engine with dual-charging (supercharger and turbocharger) was introduced. From throttle housing The G-supercharger is driven directly by the engine crankshaft via two V-belts. The eccentric shaft of the G-supercharger drives the auxiliary shaft via a toothed belt. The eccentric shaft bearings are lubricated by the engine oil system. The auxiliary shaft runs in maintenance-free anti-friction bearings. Auxiliary shaft From air filter Oil supply Eccentric shaft Oil return Via charge air cooler to throttle housing Rotors S452_004 In the 1.4 l TSI engine with dual-charging (Twincharger) from 2006, Volkswagen used another mechanical supercharging system featuring a supercharger and a turbocharger. The supercharger is driven by a V-belt and activated by a magnetic clutch. Synchronous gears S452_005 Belt pulley with magnetic clutch 6

7 Engine Components Cylinder block The 3.0 l V6 TSI engine with 90 arrangement is not new at Volkswagen Group. This engine has already been used in various Audi models. The upper section of the oil sump is made from magnesium to reduce weight. Cylinder block Lower section of crankcase (bedplate) Oil sump upper section Oil sump lower section S452_012 7

8 Engine Components The crankshaft Balancer shaft The crankshaft has a stroke of 89 mm. The CRACKED CONNECTING RODS are 153 mm long and the strength has been optimised. S452_013 Pistons Cast piston The pistons are designed as ring-carrier pistons for a compression ratio of 10.5 : 1. The piston skirts have a wear-resistant Ferrostan coating. At high output, a correct piston ring combination ensures: low BLOW-BY figures low oil consumption minimum friction and minimum wear Ring carrier 1.2 mm asymmetric crowned steel ring 1.5 mm taper-faced Napier ring 2.0 mm two-piece oil scraper ring S452_014 8

9 Cylinder head Technical features of four-valve cylinder head: Maintenance-free roller rocker fingers Camshaft control valve 1 N205 and variable valve timing on the intake side Drive for high-pressure fuel pump Chromed hollow-stem exhaust valves with sodium filling Friction-optimised camshafts Camshaft control valve 1 N205 Cylinder head cover High-pressure fuel pump Valve springs Exhaust valves (chromed hollow-stem valve with sodium filling, reinforced on valve seat) Cylinder head S452_017 9

10 Engine Components Crankcase ventilation system The crankcase ventilation system prevents BLOW-BY GASES escaping into the atmosphere. They are drawn in by the vacuum in the intake manifold via: the two cylinder head cover connections the cyclonic oil separator the pressure limiting valve and then returned to the intake manifold. Right-hand cylinder head cover connection (with integrated labyrinth oil separator) Connection to charger module Pressure control valve Cyclonic oil separator S452_015 Left-hand cylinder head cover connection (with integrated labyrinth oil separator) Connection to charger module The BLOW-BY GASES are fed into the underside of the charger module. An adapter seals the supply line from the charger module. The opening on the charger module is conical to make it easier to insert the adapter. The adapter has a lug. This lug ensures exact positioning on the outlet of the crankcase ventilation system. S452_016 10

11 Chain drive Drive with tri-oval chain sprockets Tri-oval chain sprockets Timing needs to be applied to open the valves of a cylinder. In a V6 engine, the valves are opened three times per working cycle on each cylinder bank and camshaft. As a result, greater forces act on the chain drive each time a valve is opened. These forces lead to vibrations in the timing drive particularly at higher revs. r1 > r2 Camshaft adjuster Balancer shaft drive Balancer shaft Tri-oval chain wheel Vane cell oil pump S452_077 r1 large r2 small Addendum circle diameter Technical features of the tri-oval chain drive Tri-oval chain sprockets are used on all camshafts. Chains: Newly developed roller chains (previously bush chains) are used throughout the chain drive. They have the same durability and wear resistance as bush chains. Furthermore the roller chains are quieter and have a lower frictional resistance. Chain tensioner: Reducing the forces and vibrations in the chain drive also allowed the chain tensioner damping to be reduced. This in turn reduces the friction in the chain drive. The chains are partly supplied with lubricating oil via the chain tensioner breather holes. The direction of rotation is reversed for the balancer shaft in the chain drive. All chain drives are maintenance-free. 11

12 Engine Components Ancillary component drive The following ancillary components are electrically driven: Air-conditioning compressor Hydraulic pump for power steering Brake servo pump Only the coolant pump is driven by the 1st belt drive. The 2nd belt drive drives the supercharger constantly. It is not activated or deactivated by a magnetic clutch. The electric motor/generator between the engine and gearbox takes on the function of the alternator. S452_019 Crankshaft drive Ancillary component drive 1st track Belt drive for the supercharger 2nd track Supercharger belt pulley Poly V-belt pulley for coolant pump Guide roller Tensioning element for belt drive 2 Tensioning element for belt drive 1 Vibration damper Important The electrically driven ancillary components are described in SSP 450 The Touareg Hybrid. S452_020 12

13 Air Supply Air ducting The central component of the air supply system is the charger module mounted within the V of the engine. It contains the supercharger rotors, charge air cooler and other components. Helmholtz resonator Charger module Supercharger rotors Air filter Charge air cooler S452_028 One important aim during the development of the engine was to achieve low noise development from the supercharger and air intake. A resonator has therefore been fitted between the air filter and the supercharger. This resonator is named after its inventor Helmholtz. The purpose of the resonator is to convert sound energy into other forms of energy, for example, kinetic energy. 13

14 Air Supply Supercharger basics The supercharger originates from the Roots blower. It is named after the brothers Philander and Francis Roots, who patented it in The Roots blower consists of a housing in which two shafts rotate. These shafts are connected outside the housing to a pair of gears that run synchronously at the same speed in opposite directions. Superchargers are rotary piston blowers without internal compression. One particularly important part of the design is that the rotors are sealed against each other and against the housing. The difficult part: there must be as little friction as possible. During operation (rotation of rotors), the air is transferred between the lobes and the outer wall from the air intake (fill side) to the outlet port(discharge side). Roots blower Air intake The original blowers had two-lobe rotors that displaced the air without compressing it. Rotor 2 The air intake and outlet port were arranged vertically in relation to the rotors. Rotor 1 S452_008 Outlet port The latest generation of superchargers mostly have three lobes and are screw-type. The air intake and outlet port are horizontal in relation to the screws. The air is displaced and compressed. S452_065 14

15 Advantages and disadvantages of mechanical supercharging Inside the supercharger S452_007 The following section shows the advantages and disadvantages of mechanical supercharging. Advantages Charge pressure immediately available on demand The charge pressure is delivered constantly and rises with the engine speed. The charge air does not have to be cooled so much. Long life, maintenance-friendly operation Compact design (can be mounted within the inner V in place of the intake manifold to save space) Fast, dynamic torque build-up; early peak torque, as a result good take-off performance Very short path to the cylinder for the compressed air. A very small volume of air results giving spontaneous response. Improved emissions figures Reason: The catalytic converter reaches its operating temperature faster. In turbocharged engines, part of the thermal energy is lost to drive the turbocharger. Disadvantages Very difficult to produce due to very small manufacturing tolerances (the rotors against the housing and the rotors against each other) Greater sensitivity to foreign bodies entering the clean air route Relatively heavy weight Greater noise insulation requirement Part of the engine power is lost to drive the supercharger. 15

16 Air Supply Charger module The charger module used by Volkswagen is a four-lobe screw-type supercharger. The lobes on the two rotors are twisted 160 along the longitudinal axis. This results in a continuous supply of air with little pulsation. Design The charger module fits completely within the inner V of the engine. This allowed the engine to be lower in height and thus meet the requirements for pedestrian protection. The total weight of the module is 18 kg (without coolant). Supercharger rotors Bearing cover Synchronous gears Drive shaft with bearings Front rotor bearings Decoupling element (SSI) Pulley Drive housing 16

17 By-pass pipe Throttle valve module J338 Charge pressure sender G31 Intake manifold temperature sender G72 Regulating flap control unit J808 Damping plate Charge air cooler Intake air temperature sender G42 Intake manifold pressure sender G71 S452_030 Rear rotor bearings Transport bracket Charge pressure sender 2 G447 Intake manifold temperature sender 2 G430 17

18 Air Supply Supercharger drive There is a decoupling element in the supercharger drive housing with a torsional vibration spring. The force is transferred from the belt pulley via the decoupling element to the synchronous gears. Vibrations from the crankshaft can be decoupled using the decoupling element. This makes the engine sound quieter. One positive side effect is that the belt load is reduced considerably. The power consumption of the charger module is between 1.5 and 38kW depending on the engine speed. Supercharger rotors Torsional vibration spring Charge air cooler Decoupling element Drive housing Bearing cover Pulley Synchronous gears Front rotor bearings Drive shaft with bearings S452_031 Important The change interval of the belt drive is 120,000 km. 18

19 Function A torsional vibration spring is fitted in the drive housing of the supercharger. The spring transfers the drive moment of the belt pulley to the synchronous gears. The torsional vibration spring was designed so that load alterations are decoupled softly and efficiently. Torsional vibration spring S452_035 Pulley Synchronous gears The rotors are driven by the synchronous gears and rotate exactly in opposite directions. A high number of teeth reduces the transfer of vibrations. The gears are pressed onto the rotor shafts. The fit is very precise so that the rotor lobes do not touch each other. The oil contained in the drive head does not need to be changed. Exception: If the drive head or the torsional vibration spring is damaged, a special oil refill is performed see also electronic service information system (ELSA). Rotors Rear rotor bearings The four-lobe rotors are twisted at 160. Both rotors run in maintenance-free antifriction bearings. The rotors have a special coating containing graphite to minimise wear during the running-in phase. This coating guarantees optimum sealing to prevent leakage of air. S452_036 19

20 Air Supply Control of air flow and charge pressure The supercharger is constantly driven. If the charge pressure was not regulated, the compressor would constantly deliver the maximum air flow for the respective engine speed and thus the maximum charge pressure. However, since charge air is not required in all operating states, there would be excessive pressure on the discharge side of the supercharger. This would then lead to the engine losing power unnecessarily. The regulating flap control unit J808 is fitted in the supercharger with a regulating flap to control the flow of charge air. When the regulating flap is opened, part of the displaced air volume is returned to the intake side. Idle speed Damping plate Regulating flap S452_037 Charge pressure sender 2 G447 Intake manifold temperature sender 2 G430 Intake air temperature sender G42 Intake manifold pressure sender G71 The regulating flap is open and the throttle valve is closed. Part of the delivered air volume is returned to the intake side. Partial load The regulating flap is open and the throttle valve is almost closed. Full load Throttle valve The regulating flap is closed. The air flows via the throttle valve, the two rotors and the charge air cooler to the engine. Overrun The regulating flap is open and the throttle valve is closed. Rotors S452_038 Charge air cooler Outlet ports 20

21 Regulating flap control unit J808 The regulating flap control unit J808 is used to regulate the charge pressure for the 3.0 l V6 TSI engine. It is bolted inside the charger module and connects the discharge side to the intake side via a by-pass pipe. Regulating flap Regulating flap position control motor V380 Regulating flap potentiometer G584 S452_044 Tasks of regulating flap control unit J808: Regulation of the charge pressure specified by the engine control unit Limitation of maximum charge pressure to 1.9 bar absolute 21

22 Air Supply Function Legend G584 Regulating flap potentiometer J808 Regulating flap control unit V380 Regulating flap position control motor (type: DC motor (direct current motor)) 1 Sensor voltage earth 2 Control signal 3 Sensor voltage positive Motor supply voltage S452_045 Regulating flap potentiometer G584 This component detects the current position of the regulating flap. It is mounted in the lid of the actuator housing. Its output voltage range is between 0.5 and 4.5 V. The potentiometer works according to the magnetoresistive measuring principle. It is therefore not sensitive to electromagnetic radiation (EMC). Effects of signal failure The regulating flap receives no current and is moved to the open position by a spring. If failure occurs when driving the flap defaults to the open position. No charge pressure is built up in this case. Neither the full power nor the full torque is available. The exhaust emissions warning lamp K83 lights up upon failure. Signal use The signal from the regulating flap is used to detect the position of the regulating flap. It is also used to determine the adjustment values. 22

23 Load regulation The regulating flap control unit J808 works in conjunction with the throttle valve module J338. During the development of this control system, the focus was on throttle-free operation as far as possible and, at the same time, excellent power delivery. The following diagram shows how the two flaps share the work. In the partial load/natural aspiration range, the regulating flap is open and throttle-free, and the engine throttle valve controls the load. In the charge pressure range, the regulating flap takes care of load regulation and the engine throttle valve is fully open. Load switch at 3000 rpm Opening angle [degrees] Intake manifold pressure [mbar] S452_049 Engine speed [rpm] Intake manifold pressure Regulating flap Engine throttle valve Natural aspiration range Ambient pressure Charging range 23

24 Air Supply Charge-air cooling The charger module has a charge air cooler for each cylinder bank. They are water-cooled and are connected in parallel in the charge air cooling system. Bleeder screws Right-hand charge air cooler Charger module Left-hand charge air cooler Side seal for charge air cooler Charge air cooler gasket set S452_039 Particular care should be taken when removing and installing the charge air cooler. Please note the information in the repair guide. 24

25 Noise insulation Another goal during development was to reduce the noise from the supercharger. This has been achieved with design measures in the housing. Damping plate Multi-layer damping plate A multi-layer damping plate acts against the compressed air flowing against the housing from below. S452_040 Insulating mats Insulating mats Several insulating mats are inserted between the charger module, the cylinder head and the cylinder block. They insulate against noise from the supercharger and radiation of heat from the engine to the supercharger. The charge air would become excessively hot if the insulating mats were not used. Two small insulating inserts are located at the rear of the charger module. There are further insulating mats underneath the charger module in the inner V of the engine. Whilst a larger mat is positioned between the two intake manifolds, two narrower insulating mats are fitted at the side between the intake manifolds and cylinder heads. S452_042 The adjacent illustration shows the complete set of insulating mats. S452_043 25

26 Air Supply Sensors for measuring air flow and charge pressure The air mass and the charge pressure are used as the main control variables for load regulation in the engine. There are several sensors that have exactly the same function. They measure the intake air temperature and the intake manifold pressure. The first sensor is behind the throttle valve module J338. It contains the following senders: Intake air temperature sender G42 Intake manifold pressure sender G71 The two other identical sensors are fitted in the charger module. They measure the pressure and the temperature of the air separately for each cylinder bank. It is important that the measuring point is downstream of the charge air coolers. The measured values obtained then also correspond with the actual air mass of the cylinder banks. The following senders are built into the two sensors: Intake air temperature sender G42 Intake manifold pressure sender G71 S452_046 Charge pressure sender G31 (cylinder bank 1) Intake manifold temperature sender G72 (cylinder bank 1) Charge pressure sender 2 G447 (cylinder bank 2) Intake manifold temperature sender 2 G430 (cylinder bank 2) S452_047 Charge pressure sender and intake manifold temperature sender Circuitry The intake air temperature sender G42 is a temperature sensor with negative temperature coefficient (NTC). The resistance of the intake air temperature sender creates a voltage signal to the engine control unit. Legend G42 Intake air temperature sender G71 Intake manifold pressure sender 15 Terminal Terminal 31 1 Intake manifold pressure voltage signal 2 Intake air temperature resistance signal S452_048 26

27 Intake manifold flaps Intake manifold flaps are used in the 3.0 l V6 TSI engine to improve the fuel/air mixture formation. They are located in an intermediate flange between the charger module and cylinder head. The intake manifold flaps must be in the power position (intake port open) when the intermediate flange is fitted. Intake manifold flap module, left-hand cylinder bank Operation of the shaft for intake manifold flaps Intake manifold flap potentiometer G336 S452_050 Intake manifold flaps Vacuum unit Intake manifold flap valve N316 The intake manifold flaps, which are attached to a common shaft, are operated by a vacuum unit. The vacuum required is applied by the intake manifold flap valve N316. The engine control unit activates the intake manifold flap valve N316 using a map. Effects upon failure When the N316 is not triggered or is faulty, no vacuum is applied. In this state, the intake manifold flaps close the power channel in the cylinder head due to the spring force of the vacuum unit. The engine output is therefore reduced. S452_051 27

28 Air Supply Intake manifold flap potentiometer G336 Two senders monitor the position of the intake manifold flaps: Cylinder bank 1: Intake manifold flap potentiometer G336 Cylinder bank 2: Intake manifold flap potentiometer 2 G512 Vacuum unit The senders are integrated in the vacuum unit flange. They are contact-free rotation angle senders, which use the HALL SENDER principle. A voltage signal is generated in the sensor electronics and evaluated by the engine control unit. Potentiometer for intake manifold flap G336 S452_052 Signal use The signal is used to monitor the position and for diagnostic purposes, for example, in case of wear. Effects of signal failure The position is no longer recognised correctly. Diagnosis is not possible. The exhaust emissions warning lamp K83 lights up upon failure. There may be a loss of power. Signal pattern of potentiometer for intake manifold flap Voltage signal [V] Rotation angle [degrees] S452_075 28

29 Cooling System Low-temperature cooling circuit The low-temperature cooling circuit is a separate cooling circuit with its own coolant expansion tank and two radiators. One radiator is fitted at the front right in the wheel housing, and the other radiator is in front of the main radiator (in the direction of travel). The coolant pump is fitted at the front right close to the engine. The low-temperature cooling circuit cools the charge air and the power electronics. Temperatures up to 80 C are reached in the lowtemperature cooling circuit. The coolant pump for low-temperature circuit V468 is activated using maps stored in the engine control unit. Some of the coolant flowing to the power electronics is directed past the power electronics straight to the charge air coolers via a bypass with a hose thermostat. The power electronics only have a minor cooling requirement compared with the charge air coolers. At coolant temperatures < 15 C, the hose thermostat closes to send all of the coolant, which falls at low temperatures, via the power electronics. At these low coolant temperatures, the charge air coolers also work sufficiently well even at low flow volumes. Gearbox Electric motor Power electronics Charge air cooler Engine Coolant pump for low-temperature circuit V468 Hose thermostat Coolant expansion tank Radiator - 1 Radiator - 2 Fan S452_073 29

30 Cooling System Coolant pump for charge air cooling and power electronics An electrically driven coolant pump the coolant pump for low-temperature circuit V468 is being used for the first time for the charge air cooling system and to cool the power electronics. It pumps the heated coolant from the charge air coolers in the charger module and the power electronics to two low-temperature radiators. The coolant pump is designed as a centrifugal pump. The following components are integrated in the pump module: Centrifugal pump Electric motor Electronic control S452_026 The electrical connector for the coolant pump has three pins: Battery voltage from automatic gearbox control unit J217 PWM SIGNAL from engine control unit Terminal 31 Function of coolant pump control The coolant pump is regulated in relation to the temperature measured downstream of the charge air cooler (on the basis of the map in the engine control unit) and also the pressure downstream of the charge air cooler. It always runs when the ignition is switched on. The minimum speed is 50 % of the maximum speed. The coolant pump is controlled by the engine control unit with a PWM SIGNAL. The pump electronics calculate the required pump speed from this signal and regulate the electric motor. The coolant pump signals its actual state to the engine control unit by periodically short-circuiting the PWM wire. This process runs in cycles whenever the pump is running. Effect of faults in the coolant pump for low-temperature circuit V468 Cause of fault Pump failure due to electrical fault or mechanical fault in the pump signalled by the pump to the engine control unit. Open circuit in signal wire Open circuit in a pump voltage supply wire Message An entry is made in the fault memory of the engine control unit. Since upon failure the reduced power is only noticeable at full throttle and the exhaust gas is not worsened, a warning lamp does not light up. The charge air temperature is monitored. If the system detects it is too high, the engine power is reduced. The pump runs on its own at maximum speed. A fault entry is made in the engine control unit. The exhaust emissions warning lamp K83 lights up. The pump does not work. A fault entry is made in the engine control unit. The exhaust emissions warning lamp K83 lights up. 30

31 High-temperature cooling circuit An innovative thermal management system is being used for the first time on the 3.0 l V6 TSI engine. The aim was to optimise the efficiency of the thermal distribution between the combustion engine, gearbox, interior heating and electric motor. Once the engine reaches operating temperature, it is necessary to keep the engine at the required temperature by cooling. The advantage of the optimised heat system is lower CO 2 emissions, a corresponding reduction in fuel consumption and an increase in heating comfort. This is achieved by shortening the warm-up phase after a cold start. The cooling system is regulated partly by temperature senders and partly by engine control unit maps. A coolant pump driven by the toothed belt can be activated and deactivated via vacuum control. The coolant pump for high-temperature circuit V467 ensures that the components heat exchanger for heating system ATF preheater electric motor/generator have a sufficient supply of coolant. The coolant pump V467 is tested in the same way as the coolant pump V468. The delivery volume of the pump is approx. 20 l/min at maximum speed. Example diagram Coolant temperature sender G62 Coolant pump for hightemperature circuit V467 Shut-off valve Cylinder head Temperature sender for engine temperature regulation G694 Heating system heat exchanger ATF preheater Radiator Engine block 3/2-way valve Electric motor/ generator Coolant pump Thermostat S452_067 31

32 Cooling System On-demand coolant pump The coolant pump is driven via the 1st belt drive and can be activated and deactivated as required. Coolant pump delivering Coolant pump not delivering Vacuum connection Shutter Coolant pump S452_088 When deactivated, it allows the engine to reach operating temperature as quickly as possible. After a cold engine start, the coolant pump remains switched off for up to 2 minutes and then it is activated to protect the engine. The delivery volume of the coolant pump is approx. 2 l/min while the engine is idling. Please note the filling guidelines in the electronic service information system (ELSA). 32

33 Exhaust Gas Treatment Secondary air system Another requirement for fulfilling the EU5 emissions standard is the use of a secondary air system. It ensures that the catalytic converters heat up faster and that the exhaust gas emissions are reduced. The system blows air into the exhaust system downstream of the exhaust valves for a defined period after a cold start. The unburnt hydrocarbons and carbon monoxide contained in the exhaust gas or stored in the catalytic converter then react with the atmospheric oxygen. The heat released allows the LIGHT-OFF TEMPERATURE of the catalytic converter to be reached more quickly. Secondary air inlet valves Combination valve 2 Combination valve 1 Secondary air pump motor V101 S452_053 Difference from previously used systems Two secondary air inlet valves are used to meet the EU5 emissions standard. Previously both combination valves were controlled by just one secondary air inlet valve N

34 Exhaust Gas Treatment Secondary air inlet valves The two secondary air inlet valves for controlling the two combination valves are located on the rear of the engine. They control the vacuum and are electrically activated by the engine control unit. The vacuum is supplied by the mechanically driven vacuum pump. If there is a fault in the system, the limit values of the prescribed exhaust gas emissions may be exceeded very quickly. The connectors and hoses for the secondary air inlet valves must not be interchanged because system faults could result. Secondary air inlet valve N112 Secondary air inlet valve 2 N320 Combination valves for secondary air S452_054 Checking the system for engines with EU5 emissions standard The Lambda probe-based secondary air diagnosis is used for the system check on engines fulfilling the EU5 emissions standard. The secondary air mass is calculated by the engine control unit during air input using the changing oxygen content. The diagnosis is not made during the normal secondary air operating time because the Lambda probes reach their operating temperature too late. The system is controlled separately for diagnosis. The check is performed in several phases. Measuring phase: The secondary air pump and the secondary air inlet valves are activated by the engine control unit and the combination valves are opened. The engine control unit evaluates the signals from the Lambda probes and compares them with the threshold values. If the threshold values are not reached, a fault is recorded. Offset phase: After switching off the secondary air pump, the quality of the mixture pre-control is evaluated. If the calculated value deviates too greatly, the result of the secondary air diagnosis is discarded. It is presumed that there is a fault in the mixture formation. 34

35 Oil Supply Oil system The most important aim during the development of the lubrication system was to reduce the friction inside the engine the power consumption of the oil pump and the oil throughput in the oil system. Therefore a vane cell oil pump is being used for the first time with a petrol engine. The pump has been used in diesel engines as a fuel supply pump or as a power steering pump. Oil filter Valve for oil pressure control N428 Oil pump Oil cooler Unfiltered oil intake Coolant connections Unfiltered oil channel S452_021 Filtered oil channel 35

36 Oil Supply Volumetric flow-controlled oil pump Low delivery volume One measure to reduce the drive power required for the oil pump is the use of volumetric flow control. The 3.0 l V6 engine uses a vane cell oil pump, whose delivery characteristics can be varied with an adjustment ring that rotates on bearings. Oil pressure can be applied to this adjustment ring via the control surfaces so it is moved against the force of the control springs. Valve for oil pressure control N428 activated At engine speeds up to 4,500 rpm or torques up to 300 Nm, the valve for oil pressure control N428, which is energised (terminal 15), is connected to earth (terminal 31) by the engine control unit and opens the oil channel on the second control surface of the adjustment ring. Now both flows of oil act on both control surfaces with the same pressure. The resulting forces are greater than those from the control springs and turn the adjustment ring anticlockwise. The adjustment ring rotates into the centre of the vane cell pump and reduces the size of the delivery chamber between the vane cells. The lower pressure level (1.5+/ 0.2 bar) is controlled in relation to the engine load, engine speed and oil temperature, which reduces the drive power of the oil pump. Crankshaft oil channel Low delivery volume Control surface 1 Adjustment ring S452_081 Oil pressure applied from crankshaft oil channel Counter bearing The oil pressure switch for reduced oil pressure F378 is fitted in the V of the engine and measures the low pressure level. Measuring range from bar (relative pressure). If there is a system fault, the red oil warning lamp in the combi-instrument will light up. Delivery chamber Vane cells Control surface 2 Control spring S452_082 36

37 Large delivery volume From a speed of 4,500 rpm or a torque of 300 Nm, the N428 is disconnected from the earth connection by the engine control unit J623, so that the oil channel to control surface 2 is closed. The oil pressure (3.6+/ 0.4 bar) applied now only acts on control surface 1 and applies a lower force against the force of the control spring. The control spring rotates the adjustment ring clockwise around the counter bearing. The adjustment ring is now rotated from the centre position and enlarges the delivery chamber between the individual vane cells. More oil is delivered due to the enlargement of the chambers between the vane cells. The oil channels and the bearing clearance of the crankshaft offer resistance to the increased flow of oil, causing the oil pressure to rise. This has allowed a volumetric flow-controlled oil pump with two pressure levels to be used. If the valve for oil pressure control N428 fails, the pump will only run at a high pressure level. Oil pressure development at 100 C oil temperature Solenoid valve closed when not energised Oil pressure (bar) S452_085 Engine speed (rpm) Solenoid valve not energised Solenoid valve activated Large delivery volume Control surface 1 Adjustment ring set to maximum delivery S452_083 The oil pressure switch F22 is fitted on the oil filter module and measures the high-pressure level. Measuring range from bar (relative pressure). If there is a system fault, the yellow oil warning lamp in the combi-instrument will light up. Delivery chamber Control surface 2 Counter bearing S452_084 37

38 Oil Supply Oil level sensor Usual oil level sensor Oil level and oil temperature sender G266 Using the hot-wire principle This system works according to the heated wire principle. The measuring element is briefly heated by the electronic system to a temperature above the current oil temperature. After the heating voltage is switched off, the measuring element is cooled down again to the temperature level of the oil. The oil level is calculated from the time required for cooling. S452_080 New oil level sensor in the 3.0 l V6 TSI engine with supercharger Oil level and oil temperature sender G266 Using ultrasound The ultrasonic impulses emitted are reflected by the surface of the oil. The oil level is calculated from the time difference between the transmitted and returned pulse on the basis of the speed of sound. Both sensors process their measured signals in an electronic system that is integrated in the sensor housing. A PWM SIGNAL is the output. (PWM = pulse width modulation). Advantages of the ultrasound sensor: The sensor signal is available very quickly (after approx. 100 ms) Low power consumption < 0.5 A (oil temperature and oil level sender up to 5 A) S452_086 38

39 Display of oil level on infotainment system A realistic oil level gauge is being used for the first time in the Touareg. The previously used oil dipstick has been omitted. The driver only receives warnings about the oil level via the dash panel insert. The oil level is displayed via the infotainment screen in the centre console. The display shown corresponds with the infotainment system with German system settings and is only an example. Please refer to the corresponding operating manuals for the text displayed in the dash panel insert in your language. S452_069 Two measuring methods are used to check the oil level dynamic and static measurement. Important measuring factors are: Dynamic measurement Engine speed Longitudinal and lateral acceleration from the ESP control unit Bonnet contact (bonnet must be closed) Engine temperature (engine should be at operating temperature) Driving cycle after last bonnet contact > 50 km and there must be a certain number of measured values within the driving cycle. The dynamic measurement is made while the vehicle is driving. Static measurement Ignition On (the measuring process is started as soon as the driver s door is opened to obtain a measuring result as quickly as possible) Engine oil temperature > 40 C Engine speed < 100 rpm Engine is stationary > 60 sec. The acceleration values from the ESP are also used here to check if the vehicle is standing on an incline. Furthermore the parking brake signal is used to ensure that the vehicle is stationary. The measurement is interrupted if: there are acceleration values above 3 m/s 2, oil temperature > 140 C or bonnet contact switch F266 has been operated. 39

40 Oil Supply Example of a static measurement While the vehicle is being refuelled at a service station, the bonnet is opened to top up windscreen washer fluid. The dynamic measuring cycle is interrupted by the bonnet contact switch F266 being operated. The signal from F266 is read via CAN. As a result, the oil level would only be displayed again after a driving cycle of 50 km. If, however, the conditions for static measurement are met, the driver or a mechanic can measure the oil level even if the contact switch F266 has been operated. S452_072 Gauge A = Oil level OK, do not top up oil B = Oil level too low, you must top up oil (approx. 1 l) C = Oil can be topped up (approx. 0.5 l) D = Overfill warning, please reduce oil level immediately 40

41 Oil level measurement The vehicle must be horizontal. The oil temperature must be between 60 C and 120 C. Wait briefly after stopping the engine to allow the oil to flow back into the oil sump. Switch the ignition on, press the CAR infotainment button and then the Service function button. The display of the oil pressure/oil level in the dash panel insert is displayed as follows: Possible cause Remedy Lit up Engine oil level too low Switch off engine. Check oil level. Lit up Problem with engine oil pressure Drive to a qualified workshop no faster than the maximum engine speed displayed in the dash panel insert and have the system checked. Flashing Engine oil pressure too low STOP! Do not drive on! Switch off engine. Check oil level. If the warning lamp flashes, do not drive on even though the oil level is OK. Go to a qualified workshop. Flashing Fault in engine oil system Go to a qualified workshop. Check engine oil sensor. The oil gauge tester T40178 can be used to check the oil level when there are system faults. 41

42 Fuel System Demand-regulated fuel system The demand-regulated fuel system has to a great extent been taken from the existing TSI engines. Both the electrical fuel pump and also the high-pressure fuel pump only convey the amount of fuel that the engine requires at a given moment. The electrical and also the mechanical drive power is thus as low as possible and fuel is saved. Fuel pressure sender for low pressure G410 Fuel pressure sender G247 Injectors for cylinders 2, 4, 6 N31, N33, N84 Fuel metering valve N290 Pressure free Injectors for cylinders 1, 3, 5 N30, N32, N83 Fuel filter To engine control unit Battery (+) Earth ( ) Fuel pump control unit J538 Fuel system pressurisation pump G6 High pressure S452_055 Low pressure 42

43 Injectors The injectors developed in collaboration with Continental (previously Siemens VDO) represent a further development. The six-hole injectors were configured so that optimum homogenisation of the fuel/air mixture is ensured in all operating states of the engine. Also the flow quantity was raised considerably. This reduces the injection duration (at full load less than 4 milliseconds). The time window for injection can therefore be selected so that neither a very early injection time (fuel accumulation on piston) nor a very late injection time (short period of mixture formation until ignition time) needs to be selected. The new injectors make a substantial contribution to reducing the hydrocarbon emissions increasing the combustion speed reduced knocking tendency. S452_057 43

44 Engine Management System overview Sensors Charge pressure sender G31 Intake manifold temperature sender G72 Temperature sender for engine temperature regulation G694 Intake manifold pressure sender G71 Intake air temperature sender G42 Charge pressure sender 2 G447 Intake manifold temperature sender 2 G430 Sender 1 for secondary air pressure G609 (for ULEV vehicles only) Engine speed sender G28 Throttle valve module J338 Throttle valve drive angle senders 1 and 2 for electric throttle G188 and G187 Regulating flap control unit J808 Regulating flap potentiometer G584 Brake servo pressure sensor G294 Hall sender G40 (inlet bank 1) Hall sender 3 G300 (outlet bank 1) Hall sender 2 G163 (inlet bank 2) Hall sender 4 G301 (outlet bank 2) Hybrid CAN data bus Accelerator position sender G79 Accelerator position sender 2 G185 Brake light switch F Fuel pressure sender G247 Fuel pressure sender for low pressure G410 Engine control unit J623 Knock sensor 1 G61 (bank 1) Knock sensor 2 G66 (bank 2) Fuel gauge sender G Fuel gauge sender 2 G169 Oil pressure switch F22 Oil level and oil temperature sender G266 Lambda probe G39 (bank 1) Lambda probe 2 G108 (bank 2) Lambda probe after catalytic converter G130 (bank 1), Lambda probe 2 after catalytic converter G131 (bank 2) Oil pressure switch for reduced oil pressure F378 Coolant temperature sender G62 Radiator outlet coolant temperature sender G83 Additional signals: Cruise control system switch E45 Auxiliary heater control unit J364 Starter motor relay J53 Starter motor relay 2 J695 Intake manifold flap potentiometer G336 (bank 1) Intake manifold flap potentiometer 2 G512 (bank 2) Brake pedal position sender G100 44

45 Actuators Fuel pump control unit J538 Fuel system pressurisation pump G6 Injectors for cylinders 1 6 N30 33 and N83, N84 Ignition coils 1 6 with output stage N70, N127, N291, N292, N323, N324 Throttle valve module J338 Throttle valve drive for electric throttle G186 Regulating flap control unit J808 Regulating flap position control motor V380 Engine component current supply relay J757 Motronic current supply relay J271 Activated charcoal filter solenoid valve 1 N80 Valve for oil pressure control N428 Fuel metering valve N290 Intake manifold flap valve N316 Diagnostic connection Camshaft control valves 1 and 2 N205 (inlet bank 1) and N208 (inlet bank 2) Secondary air pump relay J299 Secondary air pump motor V101 Secondary air inlet valve N112 Secondary air inlet valve 2 N320 Radiator fan control unit J293 Radiator fan V7 Lambda probe heater Z19 Lambda probe heater 2 Z28 Lambda probe 1 heater after catalytic converter Z29 Lambda probe 2 heater after catalytic converter Z30 Output signals: Engine speed to automatic gearbox control unit J217 Coolant pump for high-temperature circuit V467 Coolant pump for low-temperature circuit V468 Vacuum pump for brakes V192 Fuel system diagnostic pump V144 (for vehicles with diagnostic pump for fuel system) S452_060 45

46 Engine Management Engine control unit A Bosch MED engine control unit is used with the 3.0 l V6 TSI engine. Operating modes The direct injection method is designed for operation with a homogeneous mixture formation. The complete quantity of fuel is injected into the combustion chamber during the intake stroke. S452_061 Exception: Cold start Cold start The double injection operating mode, also called homogeneous split (HOSP), is used during this phase. This allows the catalytic converter to be heated up more quickly. The fuel is split into two quantities and injected into the combustion chamber at different times. The time windows for injection are before and after the bottom dead centre of the piston. The inlet valves are already closed for the second injection. The HOSP operating mode is always used for cold starts. It is used to heat up the catalytic converters and reduce the soot emissions. 46

47 Service Special tools Description Tool Application T40178 Oil gauge tester Checking the oil level when there are system errors S452_090 T40206/2 Mounting for charger module For mounting the supercharger on the gearbox support T40206 S452_064 47

48 Glossary Blow-by gases These are gases that escape past the pistons from the combustion chamber to the crankcase while the engine is running. This is caused by the high pressures in the combustion chamber and completely normal leaks past the piston rings. The blow-by gases are extracted from the crankcase through a crankcase ventilation system and returned to the combustion process. Hall sender Also known as Hall sensor or Hall generator, this component uses the Hall effect to measure magnetic fields and currents or for position sensing. If a current flows through a Hall sender and it is moved into a vertical magnetic field, it supplies an output voltage that is proportional to the product of the magnetic field strength and current. Cracked connecting rod This term for connecting rods refers to their manufacture. The connecting rod shank and connecting rod cap are separated from each other by deliberate fracturing (cracking). The advantage of this method is that the two pieces fit together precisely. Light-off temperature The temperature at which the conversion rate of the catalytic converter amounts to 50 %. This is very important for future emissions standards, as they require correspondingly low pollutant emissions even when the engine is cold. EMC This abbreviation stands for electromagnetic compatibility. It ensures that technical devices do not interfere with each other due to unwanted electrical or electromagnetic effects. PWM signal The abbreviation PWM stands for pulse widthmodulated signal. This is a digital signal that switches a variable (for example, an electric current) between two values. The intervals of these changes are varied depending on the control. Digital signals can be transferred by this method. 48

49 Test Yourself Which answers are correct? One or several of the given answers may be correct. 1. What advantages does a Roots blower have over a turbocharger? a) Low-cost manufacture and light weight. b) Charge pressure immediately available on demand. c) No noise insulation is necessary. 2. Which statement is true about the supercharger drive on the 3.0 l V6 TSI engine? a) The supercharger is driven via a poly V-belt with a variable, stepless ratio. b) The supercharger is driven by a poly V-belt and can be activated and deactivated by a magnetic clutch whenever required. c) The supercharger is driven via a poly V-belt with a ratio of approx. 1 : What is the task of the regulating flap control unit J808? a) The regulating flap control unit controls the charge pressure and thus also the load regulation together with the throttle flap. b) It takes care of charge pressure regulation by releasing excessive charge pressure into the atmosphere. c) It controls the flap for activating and deactivating the supercharger. d) The regulating flap control unit controls how much charge air flows through the charge air cooler. 49

50 Test Yourself 4. How are the ancillary components driven on the 3.0 l V6 TSI hybrid engine in the Touareg? a) Via a 2nd and 3rd belt drive. b) The ancillary components are driven electrically. c) The ancillary components are driven via the gearbox using gears. 5. Which statement is true about the oil pump on the 3.0 l V6 TSI engine? a) For the first time, a very light-running gear-type oil pump is fitted on this engine. b) The oil pump is a vane cell oil pump, which is controlled by a solenoid valve and can regulate at low and high pressures. c) The oil pressure is regulated constantly to 3.5 bar in all rev ranges. 6. Can you name the methods of oil level measurement previously used at Volkswagen? a) Using an oil dipstick. b) Using the inspection window in the crankcase. c) Via the oil level and oil temperature sender G

51 7. How was the oil level warning displayed until now? a) Via the EPC warning lamp in the combi-instrument. b) The oil pressure warning lamp was used. c) Only via an acoustic signal from the combi-instrument. 8. According to what principle does the new oil level and oil temperature sender G266 work? a) Radar b) Hot wire c) Ultrasound 9. Where are the two intake manifold pressure senders fitted in the charger module? a) Upstream of the throttle valve. b) Upstream of the charge air coolers. c) Downstream of the charge air coolers. Answers 1. b); 2. c); 3. a); 4. b); 5. b); 6. a), c); 7. b); 8. c); 9. c) 51

52 452 VOLKSWAGEN AG, Wolfsburg All rights and rights to make technical alterations reserved Technical status Volkswagen AG After Sales Qualifizierung Service Training VSQ-1 Brieffach 1995 D Wolfsburg This paper was manufactured from pulp that was bleached without the use of chlorine.