Service TrainingSelf-study Programme 450The Touareg Hybrid Design and FunctionFor the first time at Volkswagen, an electric hybrid drive, i.e. a combination of a combustion engine and an electric motor, will be available for use in of production in the Touareg 2011. The Touareg Hybrid is a conventional vehicle concept which has been "hybridised". The hybrid system can be classified as existing, tried-and-tested technology. During vehicle development, focus was placed on employee safety when handling the high-voltage systems. Numerous shut-off functions and back-up facilities in the hybrid system prevent undesired dangers for workshop employees. The combination of new high-voltage components and tried-and-tested technology from Volkswagen means that the Touareg Hybrid is leading the way into an increasingly electrified future.s450_148Urgent warning Please note that work which is carried out in the vicinity of, or on, the high-voltage components in the hybrid vehicle must only be undertaken by qualified and therefore authorised Volkswagen high-voltage technicians. Improper handling of the high-voltage systems may lead to life-threatening situations due to an electric shock.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 service literature.Attention Note2ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Basics of hybrid technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 What does hybrid technology mean? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 The arguments in favour of hybrid technology . . . . . . . . . . . . . . . . . . . . . . . . . 13 The hybrid concept from Volkswagen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Mechanical design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Overview of the drive train . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Electrical components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 The electric motor/generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 The power and control electronics for electric drive . . . . . . . . . . . . . . . . . . . . 24 The high-voltage battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 The high-voltage lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 The safety concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 The electric motor sensor system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 The electrical components in the hybrid technology . . . . . . . . . . . . . . . . . . . . . 44System management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Data bus communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 System layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 The innovative thermal management system . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 The displays and controls for driving in hybrid mode . . . . . . . . . . . . . . . . . . . 57 The high-voltage functional diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Special notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Special tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73Test yourself . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 773IntroductionAs part of the discussion surrounding CO2 and the increasing scarcity of fossil fuels, hybrid drives in SUV class vehicles are becoming extremely important in terms of acceptance. This hybrid technology information deals with the hybridisation of the Touareg's drive train by presenting you with a description of the parallel hybrid drive from the definition of the requirements and concept determination to the portrayal of the hybrid components. Retention of the driving performance of the conventional drive train in combination with the extensively available technical components from series production was an essential criterion on selection of the parallel hybrid concept. The standard Touareg's familiar characteristics are retained. These include - its gradability, - its off-road capability, - its trailed load, - its high-powered drive and - occupant comfort.s450_2114The parallel hybrid is a combination of a combustion engine with an electric motor/generator. In technical circles, this combination is referred to as an "electric hybrid drive". The following objectives were defined by Volkswagen for the hybrid system in the Touareg.The values of the Touareg Hybrid●● ●●● ●●●●● ●● ●●●● ●Integration of the hybrid components without body shell modifications Extensive use of standard components Extended use of new components within the Touareg platform Minimisation of the hybrid-specific production costs Maintenance-free hybrid components Full hybrid functionality, i.e. implementation of purely electric driving Achievement of consumption reduction in conformity with the market Same level of comfort as comparable hybrid systems from competitors Simultaneous retention of the Touareg's familiar comfort Robustness of the hybrid drive No reduction in driving performance on- or offroad Hybrid-related, integrated start-stop function Preference given to electric driving in the event of an adequate operating condition Brake energy recovery for charging the highvoltage battery Trailed load identical to that of the conventionally driven Touareg No limitation of permanent gradability Better driving performance in the drive-off range than a conventional driveThese criteria enable a moderate surcharge for the innovative high-voltage technology.The combustion engine is only started as required.5Basics of hybrid technologyWhat does hybrid technology mean?The term hybrid is derived from the Latin word "hybrida", and means something crossed or mixed. In technological terms, hybrid refers to a system in which two different technologies are combined with each other. In connection with drive concepts, the term hybrid technology is used in two ways: - The bivalent drive and - The hybrid drive technologyThe bivalent driveThe hybrid drive technologys450_094s450_095A bivalent drive refers to vehicles in which a combustion engine is able to combust different types of fuel in order to provide drive energy. Systems which use fossil and replenishable fuels (diesel/biodiesel) or liquid and gaseous fuels (petrol/natural gas/LPG), for example, are familiar and are increasingly found on the market.Hybrid drives refer to a combination of two different engines, which operate according to different functional principles. The present understanding of hybrid technology is the combination of a combustion engine and an electric motor/generator. It can be used as a generator for generating electrical energy, as a motor for driving the vehicle and as a starter for the combustion engine. Depending on the direction taken by this basic design, a distinction is made between three types of hybrid drive: - The micro-hybrid drive, - The mild hybrid drive, - The full hybrid drive.6The micro-hybrid driveMicro-hybrid Combustion engine Electric starter/ generatorElectric motor drive Total driving powerIn this drive concept, the electric component (electric starter/generator) is merely used to implement a startstop function. On braking, part of the kinetic energy can be reused as electrical energy (recuperation). Purely electric driving is not intended. The characteristics of the 12Volt absorbent mat battery are adapted to the frequent engine starts.Charge/ discharge modeRecuperation 12Volt battery Mild hybrid Electric motor drive Automatic gearbox s450_032The mild hybrid driveThe electric drive supports the combustion engine. Driving the vehicle purely electrically is not possible. In the mild hybrid drive, a larger part of the kinetic energy is recovered on braking and is stored as electrical energy in the high-voltage battery. The highvoltage battery and the electrical components are designed for a higher voltage and therefore a higher output. Thanks to the support provided by the electric motor, the combustion engine's operating point can be shifted to the optimal efficiency range. This is referred to as load point shifting.s450_033 Total driving power Charge/ discharge mode Recuperation12Volt batteryHigh-voltage battery DC/DC converter ClutchThe full hybrid driveA higher-performance electric motor/generator is combined with a combustion engine. Purely electric driving is possible. As soon as conditions permit, the electric motor supports the combustion engine. Slow journeys are carried out purely electrically. A combustion engine start-stop function is implemented. Recuperation is used to charge the high-voltage battery. The two systems can be decoupled thanks to a clutch between the combustion engine and the electric motor. The combustion engine is only engaged as required.Full hybridAutomatic gearboxs450_034 Total driving power Charge/ discharge modeRecuperation 12Volt battery High-voltage battery DC/DC converter7Basics of hybrid technologyThe full hybrid drives are sub-divided into three sub-groups: - Parallel hybrid drives - Power-split hybrid drives - Serial hybrid drivesThe parallel hybrid driveThe parallel design is characterised by its simplicity. It is used when an existing vehicle is to be "hybridised". The combustion engine, electric motor and gearbox are seated on a single shaft. The parallel hybrid usually has an electric motor. The total of the combustion engine's and the electric motor's individual outputs corresponds to the total output. This concept achieves a high level of carry-over parts from the original vehicle. In parallel hybrid design in four-wheel drive vehicles, the drive to all four wheels is achieved via a Torsen differential and a transfer box.Parallel hybrid BatteryCombustion engine Electric motorGearbox ClutchCharge Discharges450_036The power-split hybrid driveIn addition to a combustion engine, the power-split hybrid drive also has an electric motor/generator. Both are located on the front axle. Drive power is provided from both the combustion engine and the electric motor to the vehicle's gearbox via a planetary gear. In contrast to the parallel hybrid design, the sum of the two drive types' individual outputs cannot therefore be picked up at the wheel. Part of the output which is generated is used to drive the vehicle and the other part is stored as electrical energy in the high-voltage battery.Power-split hybrid Electric motorGearbox Planetary gearCombustion engines450_0978The serial hybrid driveThe vehicle has a combustion engine, an alternator and an electric motor. However, the difference in comparison with the two concepts described above is that the combustion engine has no possibility of moving the vehicle itself via a shaft or a gearbox. No output from the combustion engine arrives at the wheel. The electric motor acts as the vehicle's main drive. If the capacity of the high-voltage battery is low, the combustion engine is started. The combustion engine charges the high-voltage battery via an alternator. The electric motor/generator is again able to draw energy from the high-voltage battery.Serial hybridGearboxAlternator Electric motor/ generator Combustion engine s450_096The power-split, serial hybrid driveThe power-split, serial hybrid drive is a mixed form of the two above described hybrid drives. The vehicle has a combustion engine and two electric motor/ generators. The combustion engine and electric motor/generator 1 are located on the front axle. Electric motor/generator 2 is located in the rear axle. This concept applies to a four-wheel drive vehicle. The combustion engine and electric motor/generator 1 are able to actuate the vehicle's gearbox via a planetary gear. Again, the individual outputs of the drive variants cannot be picked up as total output at the wheel in this case. Electric motor/generator 2 in the rear axle is activated as required. Due to the design, the high-voltage battery is located between the vehicle's two axles.Power-split serial hybrid Electric motor/generator 1Electric motor/ generator 2Combustion engines450_1279Basics of hybrid technologyFurther termsFurther terms which are frequently used in connection with hybrid technology will be briefly explained at this point.RecuperationIn technology, this term generally refers to an energy Energy conversion recovery process. During recuperation, an existing form of energy is converted into another, reusable form of energy. s450_039 The chemical energy bound in the fuel is converted into kinetic energy in the drive train. If the vehicle is now braked using conventional brakes, surplus kinetic energy generated via brake friction is converted into Surplus kinetic energy thermal energy. The heat which is created is released is converted into into the environment and cannot therefore be reused. electrical energy and is Braking If, in contrast, a generator is used as a motor brake in stored. process Kinetic energy addition to the classic brakes, as in the case of hybrid technology, part of the kinetic energy can be recovered in the form of electrical energy and is therefore available for use again. The vehicle's energy balance improves. This is also referred to as regenerative braking. During overrun, as soon as the vehicle reduces its speed via braking with the brake pedal or rolls to a stop or drives downhillHeat Chemical energythe hybrid system switches the electric motor over and uses it as an alternator. It then charges the high-voltage battery. During overrun, it is therefore possible to "top up" an electric hybrid with electrical energy. When the vehicle rolls to a stop, only that amount of kinetic energy which the 12 Volt vehicle electrical system requires to operate is converted via the electric motor, as the alternator.10Electric motor/generatorElectric motor as a generatorThe term electric motor/generator is used instead of generator, motor and starter. Every electric motor can always additionally be used as a generator. If the electric motor's shaft is driven externally, it supplies electrical energy as a generator. If electrical energy is supplied to the electric motor/generator, it functions as a motor.Electric motor as a drive motorAn electric hybrid's electric motor/generator therefore replaces the combustion engine's conventional starter and the conventional alternator.s450_147Electric boostAlong the lines of the kick-down function in combustion engines, which makes the maximum engine power available, the hybrid drive offers an electric boost function. If it is carried out, the electric motor and the combustion engine supply their maximum outputs, which therefore add up to a higher total value. The total of the individual outputs of both drive types corresponds to the total output of the drive train.34 kW + 245kWElectric boost 279kW maximum total outputDue to the technical power loss within the electric motor/generator, however, the generator output is s450_040 less than the driving power. The driving power or the mechanical output of the electric motor is 34kW. The alternator output or the electrical output of the electric motor is 31kW. In the Touareg Hybrid, the combustion engine has an output of 245kW and the electric motor, as an alternator, has an output of 31kW. As a motor, the electric motor has an output of 34kW. Together, the combustion engine and the electric motor have an output of 279kW.11Basics of hybrid technologyStart-stop functionDue to the hybrid technology, a start-stop function can be integrated into this vehicle design. In a conventional vehicle with a start-stop system, the vehicle has to be stationary in order to deactivate the combustion engine (example: Passat BlueMotion). In a full hybrid vehicle, however, the vehicle can be driven electrically. This characteristic enables the start-stop function to deactivate the combustion engine even when the vehicle is driving or rolling. The engine is actuated as required. This may be the case in the event of high acceleration, high speed, high load or a low high-voltage battery charge. If the charge of the high-voltage battery is low, the hybrid system is able to use the combustion engine, with the electric motor/generator as a generator, to charge the high-voltage battery. In other cases, the full hybrid vehicle can be driven electrically. The combustion engine is then stopped. This is also true in slowly flowing traffic, when stationary at a red traffic light, during overrun when descending hills or when the vehicle is rolling to a stop. When the combustion engine is not running, it does not consume any fuel and does not generate any emissions. The start-stop function integrated into the hybrid system increases the vehicle's efficiency and therefore its environmental friendliness. Whilst the combustion engine is stopped, the air conditioner can continue to be operated. The air conditioner compressor forms part of the high-voltage system.STARTaSTOPb Combustion engine on Legend a - High-voltage battery voltage too low b - High acceleration required c - High speed d - Hill climbingcdSTARTeSTOPf Combustion engine off Legend e - Rolling to a stop f - Low speed g - Vehicle stopped h - Hill descentgh s450_130, s450_13112The arguments in favour of hybrid technologyTorque curve, electric motor Torque Torque curve, combustion engineWhy do we combine an electric motor/generator with a combustion engine?The combustion engine requires an idling speed to output a torque. The engine cannot output any torque when it is stationary. When the combustion engine's rotational speed is increased, its torque is increased. The electric motor reaches its maximum torque as of its first revolution. It does not require any idling speed. As its rotational speed increases, its torque decreases.800Rotational speed [rpm]800Rotational speed [rpm] s450_102The electric motor supports the combustion engine wherever this reveals weaknesses due to its concept: below the idling speed. Thanks to the support provided by the electric motor, the combustion engine can be used in the optimal efficiency range. This load point shift increases the efficiency of the drive concept.Why a full hybrid drive?Microhybrid Mild hybrid Full hybrid Start-stop function Electric boost and recuperation Pure electric driving modeIn comparison with the other hybrid drives, the full hybrid drive combines the function of the integrated start-stop system, electric boost, recuperation and purely electric driving (electric driving mode).s450_13213Basics of hybrid technologyThe hybrid concept from Volkswagens450_076The hybrid concept developed at Volkswagen, which will initially be launched in the Touareg, is based on the parallel hybrid drive. The electric motor and the combustion engine are therefore used for mechanical propulsion via a common drive train. Both drive types are seated on a single shaft. The hybrid concept from Volkswagen therefore requires significantly fewer hybrid components than is the case in the power-split or serial hybrid system. Thanks to the option of using the electric motor as both a drive motor, a generator and a starter, it has been possible to omit the starter, the alternator and a poly V-belt. Electric driving using the electric motor/generator makes it necessary to equip components which are supplied by the rotating combustion engine in conventional vehicle concepts with electric drives. These include: - Electric coolant pumps, - Electric power steering, - Electric vacuum pump for the brake servo, - Electric air conditioner compressor, - Electric pressure pump for the oil pressure in the automatic gearbox. The combustion engine and electric motor are separated from each other by a hydraulically actuated single-plate dry clutch. The hybrid vehicle's operating modes and therefore actuation of the clutch are controlled by the hybrid system. The driver has no direct influence on actuation of the single-plate dry clutch. It is controlled by an electric clutch actuator. The clutch is closed when the combustion engine is running. It is open when the combustion engine is not running.14Technical data on the Touareg HybridCombustion engine Combustion engine output Electric motor/generator Electric motor/generator output Maximum output during E boost Maximum torque during E boost High-voltage battery voltage High-voltage battery capacity Top speed Acceleration from 0 to 100km/h Additional weight due to the hybrid components 3.0 l V6 TSI engine with supercharging 245kW 3-phase AC motor/generator 31kW generator output (electrical output) 34kW motor output (mechanical output) 279kW 550Nm 288V (2 x 144V) 6.5Ah corresponding to 1.87kW/h 240km/h 6.6 seconds 175kgTorque/output graphs450_210T [Nm] O [kW] 300 b 600 500 400250a200 150 100 50300200Particularly in the lower speed range, the electric motor compensates the combustion engine's slow torque increase. For its weight class, the Touareg Hybrid therefore offers unusually high acceleration from stationary. In the output curve, the driving power of the combustion engine and the electric motor add up to a maximum total output of 279kW. This means that the output curve is increased by the amount of the electric motor's driving power, 34 kW. This occurs over almost the entire speed range. Whilst the combustion engine is running, a mixed mode occurs. As a result of this, the combustion engine's optimal efficiency range can be controlled. This load point shift increases the efficiency of the full hybrid vehicle.100 1000 2000 3000 4000 5000 [rpm] Total torque Torque, combustion engine Total output Output, combustion engine Torque increase, e.g. during electric boost Output increase due to electric motor/generator0a b15Basics of hybrid technologyLegal CO2 emission limitationA vehicle's CO2 emissions and consumption are almost proportionately connected. The higher the fuel consumption, the more CO2 which is emitted into the environment. The legal specifications for limiting CO2 emissions are therefore aimed particularly at high-volume vehicles with high outputs. The hybrid technology enables vehicles to remain below the legal limit values, even with high outputs, as the value for the CO2 which is emitted is formed as a mean value in grams of CO2 per kilometre which is covered. On integration of the kilometres covered in pure electric driving mode, the mean CO2 value per kilometre is reduced.s450_064 CO2 emissionsFuel consumption The CO2 emissions increase as fuel consumption rises.16Mechanical designOverview of the drive trains450_043The drive train on the Touareg Hybrid consists of: The 3.0l 245 kW TSI engine with supercharging, A disengagement clutch between the combustion engine and the electric motor/generator, The electric motor/generator, The automatic 8-speed gearbox 0C8 from Aisin, The drive shafts, The transfer box on the rear and front axles, The Torsen differential. The combustion engine, the clutch, the electric motor/ generator and the automatic gearbox are located behind one another on a common shaft. This method enabled installation space and weight caused by additional hybrid components to be saved. Adaptation of the propshaft tunnel from the standard Touareg was not necessary. The mechanical components will be briefly explained in the following.Further information on the combustion engine, the gearbox and the vehicle can be found in the self-study programmes: 449 "The Touareg 2011", 452 "The 3.0 l 245kW TSI Engine with Supercharging", 466 "The 8-speed Automatic Gearbox 0C8" and 469 "The Touareg 2011 Running Gear and Four-wheel Drive Concept".17Mechanical designThe 3.0l 245kW TSI engine with superchargingThe engine is a 3.0l V6 TSI with a supercharger. The supercharger is driven using a belt. The second belt on the engine drives the engaged water pump. It forms part of the entire drive train's thermal management system. Thanks to the electric motor/generator, the starter and the generator for the 12Volt vehicle electrical system have been omitted. The TSI engine does not therefore have a belt for the alternator.s450_209The disengagement clutch K0 to the combustion engineThis single-plate dry clutch is located between the engine and the electric motor/generator. The clutch actuator (pressure regulator for disengagement clutch N511) for this clutch is located behind the left front wheel housing liner. It is controlled by the hybrid system. The driver has no direct influence on this clutch. The hydraulic fluid is made available from the brake fluid reservoir. The clutch is closed when the combustion engine is running. When the vehicle is driven electrically, is in recuperation mode or is stationary, the combustion engine is deactivated and the clutch is open. When the high-voltage battery's charge is low, the hybrid system allows the combustion engine to run in order to charge the high-voltage battery. In this case, the clutch is closed.s450_12218The electric motor/generatorThe core element of the hybrid drive is the electric motor/generator. This performs three essential tasks in the hybrid system: 1. Combustion engine starter, 2. Generator for charging the high-voltage battery, 3. Electric motor for moving the vehicle.The rotor runs, without contact, in the stator. In generator mode, the electric motor has an output of 38kW. As a motor, the electric motor/generator has an output of 34kW. This difference arises from the power loss, which every electric motor/generator displays due to its design. The Touareg Hybrid can be driven purely electrically up to approx. 50km/h over flat terrain. The maximum speed is dependent on motion resistance and the high-voltage battery's state of charge. The K0 clutch is located in the electric motor/generator's housing.s450_123The 8-speed automatic gearboxThis gearbox extensively corresponds to the 6-speed automatic gearbox 09D which is already available on the market. An additional friction element and a pressure control valve are used to implement the eight gears. The gearbox is equipped with an electric pressure pump, which maintains the oil pressure when the vehicle is stationary or is driving in electric mode. A conventional mechanical pressure pump is installed in the gearbox to provide pressure in combustion engine mode.s450_11319Mechanical designTorsen differential, differential and drive shaftsThese components are carry-over parts from the Touareg. They are used without modifications for the hybrid drive. In principle, the Touareg is available with two drive train layouts: "4motion" and "4Xmotion". The Touareg Hybrid is exclusively available in the "4motion" version. This means that it is equipped with a self-locking Torsen transfer box. The drive shafts are weight-optimised and have a splined connection to the gearbox. The drive shaft splines for transmitting the torque are self-centring.More detailed information on the drive train can be found in the self-study programmes: 449 "The Touareg 2011", 452 "The 3.0 l 245kW TSI Engine with Supercharging", 466 "The 8-speed Automatic Gearbox 0C8" and 469 "The Touareg 2011 Running Gear and Four-wheel Drive Concept".20Electrical componentsThe electric motor/generators450_063 Electric motor/generatorThe electric motor/generator is located between the combustion engine and the automatic gearbox. It is an AC induction motor and is driven by a 3-phase field. The power electronics convert the 288V DC voltage to AC voltage with three phases. These 3 phases build up an electromagnetic 3-phase field in the electric motor/generator. In the service literature, the electric motor/generator is described as "electric drive motor V141".Electric motor power connectionRotor Stator s450_124 Hybrid housing Clutch pressure plate Flywheel Clutch drive plate21Electrical componentsTasks Depending on the driving situation and operating mode, the electric motor/generator performs different tasks. On switching from electric drive to combustion mode, the electric motor/generator operates as a starter for the combustion engine. During continued combustion mode, the electric motor/generator is switched over by the hybrid system to act as the generator. The electrical energy which is generated in this case is used, via voltage converters, to charge the high-voltage battery (288V) and the 12Volt vehicle electrical system battery. When the vehicle is braked, the electric motor/generator supplies electrical energy to the high-voltage battery by means of recuperation, and thereby recovers part of the surplus kinetic energy in the form of electrical energy. The pedal travel sensor is located on the brake pedal. If slight braking is detected, the hybrid system switches the electric motor/generator over so that it acts as a generator and charges the high-voltage battery. Energy which is converted into heat in conventional hydraulic brakes can now be stored in the high-voltage battery. This energy is subsequently used to drive the vehicle. During recuperation, at least the amount of energy which the 12Volt vehicle electrical system requires is converted. During this process, the combustion engine is deactivated. The electric motor/generator thus implements the concept of a start-stop system for the hybrid drive. During electric driving mode, the electric motor/generator switches back from functioning as a generator to functioning as an electric motor. When the combustion engine is decoupled, the electric motor is then used to drive the vehicle. Depending on motion resistance (aerodynamic drag, rolling, slope, frictional resistance), the electric motor is able to drive the vehicle up to approximately 50km/h. If, however, the driver requires greater acceleration, the electric motor's output is no longer sufficient to implement the driver's command. The hybrid system therefore independently starts the combustion engine. The electric motor/generator is supplied via a three-phase cable from the power electronics.22Design The electric motor consists of: The diecast aluminium housing, The internal, magnetic rotor, The stator with solenoids, An intermediate plate for connecting to the automatic gearbox's torque converter, The main electric motor bearing, The high-voltage connection with three phases.On the engine side, the clutch to the combustion engine connects with a flywheel. The three phase connections are routed to the solenoids in such a way that three adjacent solenoids are each connected to different phases.How it worksNo current With current -/+ With current +/-Magnet (rotor) Coil (stator)s450_105 The magnet is oriented according to the coil's magnetic field.The electric motor/generator is equipped with a wound stator coil, which generates a rotating magnetic field as a motor. When the electric motor/generator operates as a motor, the stator coil generates a rotating magnetic field. The rotor is fitted with permanent magnets for field generation. The speed of the induction motor is precisely specified via the frequency of the AC current which is supplied. A frequency inverter is used to enable infinitely variable synchronous motor speed regulation. The rotor position sensors constantly measure the position of the rotor. From this, the control electronics determine the actual rotational speed.If the electric motor/generator operates as a generator, the rotor is driven externally by the gearbox. As the rotor's magnetic field runs past the stator's coils, a voltage is induced in the coils for each phase. The rotor's magnetic field runs through the coils in sequence. The power electronics convert the electrical energy which is obtained into a DC charging current of 288V for the high-voltage battery.23Electrical componentsThe power and control electronics for electric drive3 connection sockets, electric motor/ generator 2 connection sockets, high-voltage battery 1 connection socket, air conditioner compressors450_149s450_062To make the system easier to understand, the power and control electronics for electric drive JX1 will be shortened to the term "power electronics" in the following. The power electronics are the electric drive's energy converter. The aluminium housing, which is mounted on the driver side between the engine and the wheel housing, contains various high-voltage system and electric drive components. They are: The control unit for power electronics, The temperature sender for power electronics, A 288Volt DC/12Volt DC voltage converter, A bi-directional DC/AC voltage converter for the electric motor/generator, The high-voltage network distributor, The two high-voltage connections for the lines from the high-voltage battery, The three high-voltage connections for the lines to the electric motor, One high-voltage connection for the line to the air conditioner compressor, The low-voltage connection to the 12Volt vehicle electrical system, A cooling system integrated into the housing, with a connection to the low-temperature cooling circuit, The safety line with safety connector.The power electronics must not be opened, and are exchanged completely in the event of damage. They can be obtained as an exchange part at a later point in time.24The voltage convertersTwo voltage converters are integrated into the power electronics. They process the high-voltage battery's 288Volt DC voltage for the electric motor and the 12Volt vehicle electrical system.Voltage converter A19This voltage converter is the interface between the vehicle's high-voltage system and 12Volt system. Task As the alternator has been omitted, the vehicle electrical system's 12Volt battery can only be charged via the electric motor/generator. To achieve this, the 288Volt DC voltage from the high-voltage system has to be converted into a charging voltage for the 12Volt vehicle electrical system battery. The 12Volt vehicle electrical system battery is located, as in the basic Touareg vehicle, beneath the driver seat.Inverter for drive motor A373-phase AC voltage To the electric motor/generatorAs the electric motor/generator is a three-phase synchronous alternator, but batteries are only able to store DC voltage, a DC/AC voltage converter is also integrated into the power electronics. Task This voltage converter transforms the high-voltage battery's 288Volt DC voltage for supplying the electric motor/generator into AC voltage with three phases. When the electric motor/generator is operated as a generator, it converts the AC voltage into 288Volt DC voltage for charging the high-voltage battery. The rectified voltage is attenuated via the high-voltage battery for the high-voltage system, and for the 12Volt vehicle electrical system, via the 12V battery beneath the driver seat and the capacitors in the power electronics.Rectified voltageAttenuated DC voltageInverter in the power electronicss450_104To the high-voltage battery25Electrical componentsThe high-voltage batteryThe high-voltage battery is deceased via the luggage compartment floor cover. It is designed as a module and contains various components belonging to the Touareg's high-voltage system. The entire highvoltage battery module weighs 85kg and may only be exchanged completely. In the service literature, the high-voltage battery is referred to as "hybrid battery A38".s450_058Warning Even AC voltages of 25Volts and DC voltages of 60Volts are hazardous to persons. It is therefore vital to observe the safety instructions in the service literature and in guided fault finding plus the warnings on the vehicle. Only qualified personnel who are aware of the hazards of high voltage may carry work out on high-voltage vehicles.The high-voltage battery cannot be compared with a conventional 12 Volt battery. During regular operation, the high-voltage battery is operated between the loose charge boundaries of 20% and 85%. A 12Volt battery would be unable to tolerate this load over a long period of time. The high-voltage battery therefore has to be regarded as a short-term store for the electric drive. Like a capacitor, it is able to absorb energy and emit it again. Recuperation, or energy recovery, can therefore essentially be viewed as an option for fuelling the vehicle whilst driving. Use of the high-voltage battery in a hybrid vehicle is characterised by alternately charging the high-voltage battery (recuperation) and discharging it (electric driving). Example: If the high-voltage battery's energy is compared with the energy which is released when fuel is combusted, the energy which the battery is able to supply corresponds to approx. 200 ml fuel. This shows that the battery still has scope for optimisation on the road to a purely electric vehicle in terms of its energy storage capability.26Design The high-voltage battery module consists of: The 288Volt high-voltage battery, The battery box, The connection and distribution box (electronics box), The air inlet and outlet ducts, The fan housing with two electric fans (12V).Air inlet ducts288 Volt high-voltage batteryElectronics boxBattery boxAir outlet ductsFan housing with two electric fanss450_150The high-voltage battery is a nickel-metal hydride battery. The battery acid has the form of a gel. No fluid would escape even in the event of large holes in the battery housing. The battery consists of two battery banks, each with a voltage of 144V. These two battery banks are connected via safety switches and, together, supply 288V. With a charge level of 75%, the high-voltage battery has a voltage of approx. 288V. The electrical charge is approx. 6.5Ah. This means that the charged energy content of the high-voltage battery is 1.87kWh. The high-voltage battery is air cooled. Two fans draw in a small amount of the air from the interior of the vehicle. Heated air discharge is ensured via a forced ventilation system in the rear bumper. The electronics box is flanged onto the high-voltage battery.27Electrical componentsThe battery cooling systemTask When charging a battery, the chemical processes which occur spontaneously during discharge are reversed. Heat is released during this thermodynamically forced process, leading to battery heating. If the heat cannot be adequately dissipated to the environment, the risk of destroying the battery is run. As the high-voltage battery in the Touareg is subject to constant charging and discharging, significant volumes of heat can also develop here. In addition to possible damage to the battery, this particularly results in increased electrical resistance on the part of the involved conductors. This leads to the fact that the electrical energy is not converted into power but is emitted as heat. The high-voltage battery therefore has a separate electric cooling system.s450_151Design Two electric cooling fans, which are actuated by the battery management control unit, are the core element of this cooling system. The two fans form part of the high-voltage battery module and intake part of the air from the interior via the battery. They operate with the 12 Volt vehicle electrical system voltage. The fans are referred to as: - Battery fan 1 V457 and - Battery fan 2 V458 in the service literature.How it works If the battery management control unit determines an excessively high battery temperature via the sensor cluster on the battery connection terminal, it actuates the two cooling fans. The air is drawn in through the intake duct, which is located beneath the rear seats, and is supplied to the high-voltage battery. The high-voltage battery's cells have small intermediate spaces between each other, through which the air is able to flow. The two fans then force the heated air laterally into the luggage compartment.28The battery boxIn order to protect the high-voltage battery, particularly in the event of a rear impact, both battery banks are surrounded by a battery box. The frame consists of welded and bolted aluminium profiles. These transmit the impact energy into the vehicle structure. The frame can also be used to lift the entire battery out of the luggage compartment floor using workshop equipment.s450_078The connection and distribution box SX1The connection and distribution box, shortened to electronics box in the following, is flanged onto the left of the high-voltage battery.Task The electronics box is used to connect the highvoltage battery to the vehicle's 288Volt system. It contains part of the safety systems for the highvoltage system and the monitoring facility for the high-voltage battery.s450_057Design The connection and distribution box (electronics box) contains: The battery regulation control unit J840, The safety connector 1 TV44, The maintenance connector for high-voltage system TW, The protective relays (contactors), The connections for the two high-voltage lines from the high-voltage battery to the power electronics.29Electrical componentsBattery regulation control unit J840Electronics box housingThe control unit is located on the left-hand side in the electronics box.Battery regulation control unitTask The battery regulation control unit monitors the battery's charge and operating status. The control unit determines values for the highvoltage battery's charge, discharge and temperature. It registers the battery temperature and regulates battery cooling via the electric cooling fans. For vehicle diagnosis purposes, it stores faults which occur on the battery or in the electronics box in its fault memory.Connection sockets for high-voltage lines s450_213All battery-relevant data are stored by the control unit as protection against tuning. High-voltage battery deep discharge or overheating can therefore also be determined at a later point in time.Safety connector 1 TV44s450_202The safety connector is located between the maintenance connector and the connection elements for the two high-voltage lines to the power electronics.Maintenance connectorSafety connectorTask The safety connector functions as a switch which is located in an electrical circuit. If the safety connector is disconnected, the switch is opened and the safety line is interrupted. The high-voltage system is now deactivated. If the safety connector is connected, the switch and therefore the safety line are closed. The monitoring system assumes that the two highvoltage lines are connected to the high-voltage battery. The hybrid system is able to run.High-voltage linesThe safety connector is mechanically connected to the high-voltage lines' locking detents. If the lines have to be disconnected, the safety connector has to be removed.30The maintenance connector for high-voltage system TWThis is located beneath the orange-coloured cover in the electronics box. Task The maintenance connector is an electrical bridge between the high-voltage battery's two battery banks. If the connector is removed, the connection is separated. The residual voltage in the high-voltage system dissipates. The high-voltage system is then deenergised. The maintenance connector is always disconnected when work has to be carried out on high-voltage components or in the vicinity of high-voltage components with metal-removing, deforming or sharp-edged tools.The maintenance connector on the electronics boxs450_155How it worksHigh-voltage line to the power electronics s450_079 Maintenance connectorRemove the orange-coloured rubber cover on the electronics box. The maintenance connector is now exposed. Release the maintenance connector by pulling the upper section to the side. Then fold the upper side of the connector upwards. The maintenance connector is now released and can be removed. To recommission the high-voltage system, reposition the maintenance connector. Precise information on carrying out measurements for recommissioning can be found in guided fault finding.Electronics boxBattery bank 1 (144 Volt) Safety lineBattery bank 2 (144 Volt)31Electrical componentsRemoval of the maintenance connector One way of deactivating the high-voltage system is to actuate the maintenance connector, because it acts as an electric bridge between the two halves of the battery. The process is carried out with two defined switching positions.Maintenance connector connecteds450_184In the first position, the safety line is separated. The protective relays (contactors) are then opened as an emergency shut-off facility. The safety line is used primarily to protect against arcs.Maintenance connector in position 1s450_185In the second position, the series connection between the two halves of the battery is separated. The maintenance connector can now be removed from the retainer. The high-voltage system is now deactivated and must be checked to determine whether it is de-energised.Maintenance connector in position 2s450_186Warning: Only qualified high-voltage technicians may remove this maintenance connector to de-energise the system.32The fuse in the maintenance connector A blow-out fuse for the high-voltage system is integrated into the maintenance connector. The system is usually fused to 125A. In order to exchange the fuse, the cover on the top of the maintenance connector has to be released.s450_183 Blow-out fuse in the maintenance connectorWarning: Only qualified high-voltage technicians may remove this maintenance connector to de-energise the system.The protective relaysIn addition to the battery regulation control unit, the electronics box also contains the protective relays, also called the contactors. The contactors are technical devices from the field of electrical engineering, and are used to protect the highvoltage system and therefore the vehicle electrical system from faults in individual sections of the system. If a fault is ascertained by the hybrid monitoring system, the contactors are opened. This is necessary, for example, in the event of an accident involving the hybrid vehicle. In this case, the airbag control unit triggers the contactors.Task The two protective relays connect the high-voltage battery to the high-voltage system. In addition to the maintenance connector, they serve to separate the two areas from each other.33Electrical componentsDesign Each relay is an electromagnetically actuated switch via which a high operating current can be switched on and off using a low control current. If the relay coil is supplied with current by the control unit, an armature is pulled into the coil. As a result of this movement, a mechanical switch for the operating current is closed. If the coil is not supplied with current, the switch for the operating current remains open.How it works When the Touareg's vehicle electrical system is activated, the battery regulation control unit actuates the protective relays and therefore switches on the 288Volt system. If the ignition (terminal 15) is not activated, the contactors are open. If the ignition is switched on, the contactors are closed. Shutting off the 12Volt vehicle electrical system opens the contactors.Effects in the event of failure If the contactors cannot be closed after switching on the ignition, the high-voltage system cannot be activated. Firstly, the "Ready" lettering in the instrument cluster does not light up. Secondly, the combustion engine will not start, as the electric motor cannot be switched on. If the contactors cannot be opened, the high-voltage system cannot be de-energised. One possible cause may be the protective relays' 288Volt switch contacts "sticking". This is the only case in which the vehicle cannot be de-energised.34The high-voltage linesThe high-voltage system's electrical lines differ significantly from the lines in the rest of the vehicle electrical system and the 12Volt vehicle electrical system. Due to the high voltage and current strengths, they have a significantly larger cross-section and are connected via special connectors. Unlike the 12 Volt vehicle electrical system, the high-voltage system has no electrical potential to the body. In order to draw attention to the danger of high voltage, all of the high-voltage system's cables are coloured orange throughout. All manufacturers of electric vehicles have agreed to colour all lines which conduct highvoltage orange. The high-voltage lines are secured to prevent polarity reversal. They cannot be incorrectly installed, as they are colour and mechanically coded. The high-voltage system has a potential equalisation line. This line is monitored by the hybrid system. The following line sections are formed in the high-voltage system: - Two high-voltage lines from the high-voltage battery to the power electronics, - Three high-voltage lines from the power electronics to the electric motor/generator, - One two-wire high-voltage line from the power electronics to the air conditioner compressor.s450_044 One high-voltage line from the power electronics to the air conditioner compressor Three high-voltage lines from the power electronics to the electric motor Two high-voltage lines from the high-voltage battery to the power electronics35Electrical componentsFrom the high-voltage battery to the power electronicsBetween the high-voltage battery and the power electronics, the electrical charges are transmitted via two orange-coloured high-voltage lines. Both lines conduct a potential. A DC voltage of 288Volt is present. The 1-pin lines are designed with a screen.High-voltage connector 1 (negative) brown ring s450_072a d b c s450_083 eHigh-voltage connector 2 (positive) red ring s450_071From the power electronics to the electric motor/generatorIn the power electronics, the high-voltage battery's 288Volt DC voltage is converted by a DC/AC voltage converter into a three-phase AC voltage (alternating current) for operating the electric motor. The electric motor is connected to the power electronics via three short high-voltage cables. Like all of the others, the three-phase lines are colour and mechanically marked and coded so that they cannot be interchanged with each other. For the corresponding designations of the lines in the service literature, please refer to the parts catalogue.High-voltage line connector between power electronics and electric motor/generator s450_074s450_08336From the power electronics to the air conditioner compressorDue to the air conditioner compressor, the air conditioner forms part of the Touareg Hybrid's highvoltage system. This innovative actuation of the compressor has the advantage that the climate inside the vehicle can be controlled when the combustion engine is switched off. The air conditioner remains active depending on the battery's state of charge. If the high-voltage battery's charge declines further, the system automatically starts the combustion engine. The air conditioner compressor is connected to the power electronics via a line. Thanks to colour and mechanical coding, it is not possible to interchange the high-voltage lines. This two-pin line is designed with screening and the safety line's line. If one of this line's two connectors is disconnected, this corresponds to removing a safety connector. The high-voltage system is deactivated.a d b c s450_083 s450_073 eConnector for connecting the air conditioner compressor to the power electronicsLegend a - Electric drive motor V141 (electric motor) b - Electric air conditioner compressor V470 c - Power and control electronics for electric drive JX1 d - Connection and distribution box SX1 (electronics box) e - High-voltage battery37Electrical componentsThe safety conceptIn the event of improper handling, the high-voltage current system poses a danger due to its high voltage of 288 Volts. In order to reduce the potential danger and to avoid improper work on the system or unintentional contact with high voltage, the Touareg Hybrid is equipped with an extensive safety concept. The safety concept components include: The electric safety line with safety connector, The ignition lock, The protective relays in the electronics box, The airbag control unit, The maintenance connector, The battery regulation control unit.The electric safety line with safety connectorThe safety line is a safety concept which contains a mechanical and an electric component. Task The safety line guarantees that the entire high-voltage system's voltage is switched off as soon as a highvoltage component is disconnected from the system. Together with a locking bow, the safety connector additionally forms a mechanical lock, which prevents the high-voltage lines from being disconnected whilst conducting voltage. The safety line is like an electrical circuit which is closed by its safety connectors. If this circuit is opened by removing the safety connectors, the high-voltage system shuts off. The safety connectors have to be removed before high-voltage lines can be disconnected from the highvoltage components. This guarantees that the system is not conducting voltage when the lines are disconnected.Safety connector connection Locking bows450_061 High-voltage line connections The safety connector bracket with the mechanical locking bow (red) on the electronics box with the safety connector removed and high-voltage lines disconnected38How the safety line worksSafety line closedd e a b cfg k nhi l m s450_128All of the high-voltage system's components are connected to each other via a separate low-voltage line in a loop. In this case, the component's connection with the safety line is designed as a contact breaker point. When all components are ready to operate, the contact breaker points are closed. If voltage is now applied to the safety line, current is able to flow because the line is not interrupted. The measurable current is therefore an indication of the fact that all of the safety line's components are ready to operate. The function of the safety line is comparable with cold monitoring in the case of bulbs.All high-voltage components are ready to operate.Safety line interrupted f eIf a contact breaker point is opened because a component is not ready to operate or because the safety connector has been removed, the safety line is interrupted. No current is able to flow on application of a voltage. This is an indication of the fact that the high-voltage system is not ready to operate. The check to determine whether the safety line is closed or interrupted is carried out by the battery regulation control unit in the electronics box. If the control unit ascertains that the line is interrupted, it does not actuate the protective relays and therefore interrupts the high-voltage battery's connection to the high-voltage system.s450_129 Example: Disconnection of the high-voltage line from the compressor Legend a - Maintenance connector b - Safety connector 1 c - Traction system distributor cover d - Safety connector 2 e - Air conditioner compressor connector f - Air conditioner compressor g - Power electronics h - Power electronics 3-phase cover i - Electric motor connection box k - Battery regulation control unit l - 14-pin connector for motor/generator wiring sensors m - Electric motor/generator n - High-voltage battery with electronics box39Electrical componentsHow the mechanical lock with the safety connector worksSafety connectorAt the start of this work, it is vital to remove the maintenance connector. This work must only be carried out by a high-voltage technician qualified by Volkswagen. If the high-voltage line to the power electronics is connected to the electronics box, a locking bow must be swiveled over the two connectors before the safety connector can be inserted. In connection with the safety line, this means that the high-voltage system is only supplied with current when the safety connector is connected. The high-voltage connections are therefore always inserted when no current is flowing. In turn, the high-voltage line can be disconnected from the electronics box only if the safety connector has been removed beforehand. Only then can the locking bow be swivelled back to disconnect the highvoltage line's connectors. As the safety connector has had to be removed beforehand, the safety line is interrupted and the battery management control unit has decoupled the high-voltage battery via the protective relays. No further voltage is therefore present at the contacts for the high-voltage line, and no electric shocks can occur when disconnecting the high-voltage line.Locking bowHigh-voltage lines450_068 Electronics box1. Remove safety connector2. Fold locking bow backwardss450_0693. Pull high-voltage line from the socket.Attention! This work must only be carried out by a qualified Volkswagen highvoltage technician.s450_07040The ignition lockVia the information "Ignition key is inserted", the ignition lock requests the high-voltage system to switch to drive readiness mode. For the battery management control unit, the information "Ignition key is inserted" is a condition which has to be met so that the control unit actuates the protective relays for coupling the high-voltage battery to the high-voltage current system. If the ignition key is removed, the control unit automatically separates the highvoltage battery from the high-voltage system.Battery regulation control unit shut-off measuresThe battery regulation control unit closes the contactors as soon as terminal 15 (ignition on) has been switched on. If the voltage supply for the battery regulation control unit is disconnected, the contactors are opened. Vehicle electrical system off means that the high-voltage system is off. Fire brigades can introduce measures for deactivating the high-voltage system on-site. The contactors are opened by the battery regulation control unit J840 when: The ignition is deactivated The safety line is separated The seat belt pre-tensioners have triggered The airbags have triggered The 12V battery is disconnected from the vehicle electrical systemThe airbag control unitTo reduce the danger posed to occupants and rescue services by the high-voltage system in the event of a crash, the crash detection signal from the airbag control unit is also evaluated by the battery regulation control unit J840. If a crash is detected, the battery regulation control unit disconnects the high-voltage battery from the high-voltage current system via the protective relays. In the first crash stage, in which only the seat belt pre-tensioners have triggered, the protective relays are opened. This process is reversible. This means that the protective relays can be closed again following a new ignition cycle. If the seat belt pre-tensioners and the airbags have been triggered in the second crash stage, disconnection of the high-voltage battery from the high-voltage system is irreversible. This means that the protective relays can not be closed again via a new ignition cycle. This process must be carried out using the workshop tester. The triggered airbags therefore indicate to the rescue services that the contactors have been opened in the event of a crash and that the high-voltage system has therefore been disconnected from the high-voltage battery.41Electrical componentsThe electric motor sensor systemThe rotor position sendersAs the combustion engine with its speed senders is mechanically decoupled from the electric motor in electric mode, the electric motor requires a separate sensor system to determine the rotor position and the rotor speed. Three speed sensors are integrated into the electric motor for this purpose. They are: Drive motor rotor position sender 1 G713 Drive motor rotor position sender 2 G714 Drive motor rotor position sender 3 G715s450_203Signal use Based on the signals from this total of three individual sensors the engine and gearbox management system receives information regarding whether, and the speed at which, the electric motor is rotating. The signal is used to control the following high-voltage drive components: Electric motor/generator as a generator Electric motor/generator as a motor Electric motor/generator as a combustion engine starterDrive motor rotor position sender 1 G713 Drive motor rotor position sender 2 G714 Drive motor rotor position sender 3 G715Effects in the event of failure In the event that the sensors fail, the warning lamp for the hybrid system appears in the instrument cluster. The nearest workshop must be visited. Starting the engine again is no longer possible. The request not to switch off the combustion engine then appears in the instrument cluster. This is to ensure that the vehicle can still reach a workshop.42Drive motor temperature sender G712This sensor is cast into synthetic resin in the electric motor's housing.Signal use It detects the temperature of the electric motor. The cooling circuits form part of the innovative thermal management system. The electric motor temperature sensor signal is used to control the high-temperature circuit's cooling capacity. Via an electric auxiliary coolant pump and the combustion engine's engaged water pump, the cooling capacity can be regulated from standing coolant to maximum.Drive motor temperature sender G712, cast into the electric motor's housings450_204Effects in the event of failure In the event that the sensor fails, the warning lamp for the hybrid system appears in the instrument cluster. The nearest workshop must be visited. The vehicle remains able to drive, but hybrid drive operation is very limited.Warning Even AC voltages of 25Volts and DC voltages of 60Volts are hazardous to persons. It is therefore vital to observe the safety instructions in the service literature and in guided fault finding plus the warnings on the vehicle. Only qualified personnel who are aware of the hazards of high voltage may carry work out on high-voltage vehicles.43Electrical componentsThe electrical components in the hybrid technologyBecause the combustion engine is decoupled and deactivated during electric driving with the electric motor/ generator, the components which perform comfort- and safety-relevant tasks for vehicle operation must be driven electrically. In the Touareg Hybrid, all functions which are guaranteed by a rotating combustion engine in a conventionally driven vehicle are carried out by means of electric motors and pumps. This is necessary to adequately supply e.g. the brake system, the power steering system, the gearbox hydraulics and the vacuum system with the required pressures even in electric mode. Depending on the ancillary units' power requirements and power consumption, these are assigned either to the 12Volt vehicle electrical system or the 288Volt high-voltage system.12Volt componentsAll electrically driven ancillary units are assigned to the 12Volt vehicle electrical system. Only the air conditioner compressor is connected to the high-voltage system. All electrically driven ancillary units are capable of diagnosis.The 12V batteryThis is installed beneath the driver seat and supplies the 12V vehicle electrical system with electrical energy. The hybrid vehicle has no conventional 12V alternator. The 12Volt vehicle electrical system supply is made available by the high-voltage battery via a DC/DC converter in the power electronics. Battery monitoring is carried out via the battery monitor control unit J367 with battery sensor. This is located on the negative terminal of the 12V battery cable. If the 12V battery is discharged, it can be charged via the jump-starting points in the engine compartment. The battery charge is used to activate the control units, close the high-voltage protective relays and make the ignition available for the combustion engine.J367 battery monitor control unit with battery sensors450_16044The pressure regulator for disengagement clutch K0 N511The pressure regulator is installed in the front left wheel housing above the wheel housing liner. In a conventional Touareg, this is the location of the auxiliary heater. Task The pressure regulator supplies the release bearing of the single-plate disengagement clutch between the combustion engine and the electric motor with the necessary hydraulic pressure. The hydraulic fluid reservoir is the brake fluid expansion tank. When the ignition is deactivated, the clutch is closed. The electric motor is therefore immediately able to rotate the combustion engine when the combustion engine is started. The clutch is always closed when the combustion engine is running. Design A hybrid warning lamp is displayed on the instrument cluster display. The request not to switch off the combustion engine additionally appears in the instrument cluster display, as restarting is not possible. A workshop must be visited. The pressure regulator is a spindle actuator. The "brake fluid" is pressed to the clutch release bearing via an electric motor. The pressure regulator ca