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Condenser > < Mechanically driven air conditioner compressor

A4 Mk2

Electrically driven air conditioner compressor for vehicles with a high-voltage system
Electrically driven air conditioner compressor for vehicles with a high-voltage system
Hybrid vehicles
For all work on vehicles with a high-voltage system, note the additional warning instructions for working on such vehicles → Chapter „Warning instructions when working on vehicles with high-voltage system“ and → Electrical system; Rep. gr.93.
  WARNING
Safety hazard: the engine can start unexpectedly.
Before carrying out general work on a vehicle with high-voltage electrical system, switch off the ignition and remove the ignition key from the vehicle.
  WARNING
Working on vehicles with high-voltage wiring:
l  Do not support yourself or tools on high-voltage wiring or associated components --> this can damage the insulation.
l  High-voltage wiring must not be excessively bent or kinked --> this can damage the insulation.
l  The round high-voltage connectors are colour-coded with an external coloured ring and are provided with mechanical coding or guide lugs. It is important to observe this coding when joining up the round high-voltage connectors, otherwise the connectors can be damaged.
  DANGER!
Risk of fatal injury if high-voltage components are damaged.
Observe the following when working in the vicinity of high-voltage components or wiring:
t  It is not permitted to use cutting or forming tools, other sharp-edged tools or heat sources such as welding, brazing, soldering, hot air or thermal bonding equipment.
t  Before starting work, visually inspect the high-voltage components in the areas involved.
t  Before working in the engine compartment, visually inspect the power electronics -JX1-, electric drive motor -V141-, air conditioner compressor -V470- and high-voltage wiring.
t  Before working on the vehicle underbody, visually inspect the high-voltage wiring and covers.
t  Before working on the rear section of the vehicle, visually inspect the high-voltage wiring and the electro-box with the maintenance connector for high-voltage system - TW -.
t  Visually inspect all potential equalisation lines.
Check the following when making the visual inspection:
t  There must be no external damage on any component.
t  The insulation of the high-voltage wiring and potential equalisation lines must not be damaged.
t  There must be no unusual deformation of the high-voltage wiring.
t  All high-voltage components must be identified by a red warning sticker.
If work is necessary in the vicinity of high-voltage system components, perform a visual inspection of the high-voltage components and wiring to check for damage → Chapter and note → Electrical system; Rep. gr.93.
If work is necessary on high-voltage system components, de-energise the high-voltage system → Electrical system; Rep. gr.93 and note → Electrical system; Rep. gr.93.
De-energising high-voltage system
  DANGER!
Voltage can cause fatal injury.
Danger of severe or fatal injuries from electric shock.
t  For reasons of safety, persons with life-preserving or other electronic medical devices in or on their body must not perform any work on the high-voltage system. Such medical devices include internal analgesic pumps, implanted defibrillators, pacemakers, insulin pumps and hearing aids.
t  The high-voltage system may only be de-energised by a suitably qualified person (Audi high-voltage technician).
t  It must be definitely confirmed that the high-voltage system is de-energised. The system may only be de-energised using the vehicle diagnostic tester via „Guided Fault Finding“.
t  The qualified person (Audi high-voltage technician) confirms that the system is de-energised and uses the locking cap -T40262- to ensure that the system cannot be re-energised. The ignition key and the maintenance connector for high-voltage system - TW - should then be stored in a safe place by the qualified person.
t  The qualified person (Audi high-voltage technician) marks the vehicle by attaching the appropriate warning signs.
  Note
t  De-energising high-voltage system:
t  Connect vehicle diagnostic tester
t  Select Guided Fault Finding mode
t  Using the Go to key, select the following menu items in succession
t  Function/component selection
t  Body
t  Electrical system
t  Self-diagnosis compatible systems
t  8C - Hybrid battery management -J840
t  8C - Hybrid battery management, functions
t  51 - De-energise high-voltage system (Rep. gr. 93)
Re-energising high-voltage system
  DANGER!
Voltage can cause fatal injury.
Danger of severe or fatal injuries from electric shock.
t  For reasons of safety, persons with life-preserving or other electronic medical devices in or on their body must not perform any work on the high-voltage system. Such medical devices include internal analgesic pumps, implanted defibrillators, pacemakers, insulin pumps and hearing aids.
t  The high-voltage system may only be re-energised by a suitably qualified person (Audi high-voltage technician).
t  The system may only be re-energised using the vehicle diagnostic tester via „Guided Fault Finding“.
t  The vehicle is then made ready for operation again by the qualified person (Audi high-voltage technician).
t  The qualified person (Audi high-voltage technician) marks the vehicle by attaching the appropriate warning signs.
  Note
t  Re-energise high-voltage system:
t  Connect vehicle diagnostic tester
t  Select Guided Fault Finding mode
t  Using the Go to key, select the following menu items in succession
t  Function/component selection
t  Body
t  Electrical system
t  Self-diagnosis compatible systems
t  8C - Hybrid battery management -J840
t  8C - Hybrid battery management, functions
t  51 - Re-energise high-voltage system (Rep. gr. 93)
  DANGER!
When working on a vehicle with the ignition switched on or while the drive system is active, the engine can start unexpectedly and exhaust fumes can cause a health hazard in closed rooms. Moving parts can trap or draw in parts of the body and/or clothing (safety hazard).
Before switching on the ignition, perform the following steps:
t  Move selector lever to position P
t  Activate parking brake
t  Switch off ignition
t  Open bonnet
t  Connect battery charger (e.g. -VAS 5095A-) to jump-start connections of 12 V electrical system
t  Switch on ignition
–  To minimise the number of automatic engine starts when the vehicle's drive system is active during test and measurement work, charge the vehicle batteries e.g. with the battery charger 60A -VAS 5904- in battery standby mode → Electrical system; Rep. gr.27 and → Electrical system; Rep. gr.93.
–  For test and measurement work that requires the vehicle's drive system to be active or the ignition to be switched on, move the selector lever to position „P“, activate the parking brake and arrange the tools needed so that they cannot come into contact with moving components of the engine and so that they cannot even come near to components that turn when the engine is running.
   
Electrically driven air conditioner compressor
  WARNING
Danger of short circuit
The air conditioner compressor operates at up to 288 V in a speed range between 800 and 8600 rpm.
Avoid contact with the air conditioner compressor when switching on the ignition or starting the drive units - danger of short circuit.
t  The air conditioner compressor draws refrigerant gas from the evaporator, compresses it and sends it to the condenser.
t  The electric motor of the air conditioner compressor is supplied with power by the power and control electronics for electric drive -JX1-.
t  The control unit for air conditioning compressor -J842- integrated into the air conditioner compressor regulates the speed and thus the output of the air conditioner compressor (electrical air conditioner compressor -V470-) on the basis of the request received via the data bus → Vehicle diagnostic tester, „Guided Fault Finding“ function for air conditioner and battery regulation.
t  The electrically driven air conditioner compressor is not fitted with an air conditioner compressor regulating valve -N280-.
t  Prior to installation, check the air conditioner compressor and holder attachment points. The contact surfaces must be clean and free from rust and grease. If this is not the case, treat the contact surfaces accordingly with the contact surface cleaning set -VAS 6410- → Electrical system general information; Rep. gr.97.
  Note
t  If the control unit for air conditioning compressor -J842- is defective, the amount of refrigeration oil in the new air conditioner compressor must be adjusted. The refrigerant circuit does not have to be flushed with R134a.
t  The control unit for air conditioning compressor -J842- and the electrical air conditioner compressor -V470- form one component and cannot be separated at present.
t  The electrically driven air conditioner compressor is not fitted with -N280-. The output of the air conditioner compressor is regulated externally by way of the air conditioner compressor speed → Current flow diagrams, Electrical fault finding and Fitting locations and → Vehicle diagnostic tester, „Guided Fault Finding“ function for air conditioner and battery regulation.
t  At present, the electrically driven air conditioner compressor operates on the principle of a spiral-type supercharger.
t  The air conditioner compressor contains refrigerant oil which mixes with refrigerant R134a at all temperatures.
t  The rating plate indicates the refrigerant for which the air conditioner compressor is designed.
t  The integrated electronics regulate the output of the air conditioner compressor (and thus the pressure on the low-pressure end) within the specified range (control characteristic) by way of the speed.
t  The engine should only be started after the refrigerant circuit has been assembled completely.
t  The air conditioner compressor has an internal oil circuit to ensure that the air conditioner compressor is not damaged when the refrigerant circuit is empty. This means that roughly 40 to 50 cm3 of refrigeration oil remains in the air conditioner compressor.
t  Like the mechanically driven air conditioner compressor, the electrically driven air conditioner compressor has a high-pressure safety valve.
t  On vehicles with battery cooling, hybrid operation is only possible with the air conditioner charged and with no air conditioner faults stored → Vehicle diagnostic tester, „Guided Fault Finding“ function for air conditioner and battery regulation.
t  After installing the air conditioner compressor and then filling the refrigerant circuit, first start up the electrically driven air conditioner compressor by way of the „Compressor run-in“ function of the basic setting routine. Otherwise, the air conditioner compressor may be damaged if refrigeration oil has accumulated in the compression chamber of the air conditioner compressor on account of inappropriate storage prior to installation → Vehicle diagnostic tester, „Guided Fault Finding“ function for air conditioner and battery regulation
t  Electrically driven air conditioner compressors are only to be actuated with the refrigerant circuit charged. Running the air conditioner compressor with the refrigerant circuit empty could lead to compressor damage → Vehicle diagnostic tester, „Guided Fault Finding“ function for air conditioner and battery regulation.
  N87-10738

Condenser > < Mechanically driven air conditioner compressor