Removing and installing mechanically driven air conditioner compressor, vehicles with high-voltage system — AUDI

🧭 Before you start

Have the high-voltage system de-energised, remove the engine cover and move the expansion tank aside. Detach the refrigerant lines and air pipe, expose and unplug the high-voltage connector keeping it horizontal, and cap both halves. Remove the fixings, unplug the low-voltage connector and lift the compressor out. Refit, lock the connector, evacuate and charge the circuit, re-energise, clear event memory and start the compressor with the run-in function.

Fits: Audi A6/A7 C7 (4G, 2011–2018); platform code 4X

• Opens: refrigerant (A/C)

Don't miss

• Only a qualified high-voltage technician may de-energise and re-energise the system.
• Unplug the high-voltage connector horizontally without turning it, and never bend the cables.
• Cap the high-voltage connector and mating plug with clean bungs while apart.
• The removed compressor holds an unknown amount of refrigerant oil; follow the compressor renewal notes.
• After charging, start the compressor with the run-in function before normal use.
• Visually inspect high-voltage parts before work and use no cutting tools or heat near them.

Written for this job from the workshop steps below · TorqFix editorial.

📋 Procedure

1. ⚠ Risk of fatal injury if high-voltage components are damaged.Observe the following when working in the vicinity of high-voltage components or wiring: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.Before starting work, visually inspect the high-voltage components in the areas involved.Before working in the engine compartment, visually inspect the power and control electronics for electric driveJX1, electric drive motor V141, air conditioner compressor V470 and high-voltage wiring. Before working on the vehicle underbody, visually inspect the high-voltage wiring and covers. 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 . Visually inspect all potential equalisation lines.Check the following when making the visual inspection:There must be no external damage on any component. The insulation of the high-voltage wiring and potential equalisation lines must not be damaged. There must be no unusual deformation of the high-voltage wiring. All high-voltage components must be identified by a red warning sticker. — Switch off ignition.
2. De-energise high voltage system Electrical system, hybrid93De-energising high-voltage system. [Note: De-energising high-voltage system:Connect vehicle diagnostic testerSelect Guided Fault Finding modeUsing the Go to key, select the following menu items in successionFunction/component selectionBodyElectrical systemSelf-diagnosis compatible systems8C - Hybrid battery management -J8408C - Hybrid battery management, functions51 - De-energise high-voltage system (Rep. gr. 93)]
3. ⚠ Potentially fatal voltageRisk of fatal or serious injury from electric shocks. The high-voltage system may only be de-energised by a suitably qualified person (Audi high-voltage technician). 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”". The qualified person (Audi high-voltage engineer) makes sure the system has been isolated from the supply and guards it against renewed switch-on by means of the locking cap T40262. Renewed switch-on of the system is additionally prevented by the qualified person taking charge of the ignition key and the maintenance connector for high-voltage system TW .The qualified person (Audi high-voltage technician) marks the vehicle by attaching the appropriate warning signs. — Discharge refrigerant circuit Air conditioner with refrigerant R134a87Refrigerant circuit.
4. Detach engine cover panel (arrows)10Engine cover panel; Removing and installing engine cover panel.
5. Unfasten coolant expansion tank from bracket and swivel to one side.

6. Detach refrigerant lines from air conditioner compressor .
7. Unfasten hose clips (arrows).
8. Remove bolt (1) and detach air pipe.
9. Expose attachment points (1 and 3) of high-voltage system wire (4) on engine.
10. ⚠ Risk of damaging cable or connector of high-voltage systemTake care not to bend high-voltage cables.After releasing the connector, make sure it is horizontal when unplugging it. Do NOT turn the connector. — Pull locking element in direction of (arrow).
11. Unplug connector from air conditioner compressor; connector must be horizontal and must not be turned.
12. Cover high-voltage cable connector and mating plug at air conditioner compressor to prevent damage and contamination (e.g. with clean plugs from engine bung setVAS 6122).
13. Remove nuts (1 and 2) and bolt (3).
14. Remove threaded pins (1 and 3). [Note: Bolts may also be fitted instead of threaded pins (1 and 3)Electronic parts catalogue.]
15. Move air conditioner compressor (2) slightly to the side and unplug electrical connector (4) (for low voltage on air conditioner compressor).
16. Lift out air conditioner compressor upwards and towards front. [Note: When it is removed, the air conditioner compressor contains an indeterminate amount of refrigerant oil. For this reason it is important to observe the notes on renewing the compressor Air conditioner with refrigerant R134a87Renewing components of refrigerant circuit.] [Note: After installing the electrically driven air conditioner compressor and then charging the refrigerant circuit, first start up the compressor by way of the "“Compressor run-in”" function of the basic setting routine. Otherwise, the air conditioner compressor may be damaged if refrigerant oil has accumulated in the compression chamber of the air conditioner compressor due to inappropriate storage prior to installation in "“Guided Fault Finding”" mode for air conditioner and battery regulation.An electrically driven air conditioner compressor may only be activated when the refrigerant circuit is charged. Running the air conditioner compressor with the refrigerant circuit empty could lead to compressor damage ("“Guided Fault Finding”" for air conditioner and battery regulation).]
17. Evacuate and charge refrigerant circuit Air conditioner with refrigerant R134a87Refrigerant circuit.
18. Plug in and lock high-voltage system connector at air conditioner compressor.
19. ⚠ Risk of damaging cable or connector of high-voltage systemTake care not to bend high-voltage cables.Always plug the connector in at the air conditioner compressor in the specified position (connector coding). Do NOT turn the connector. — Check connector for dirt and damage.
20. Plug in connector at air conditioner compressor.
21. Fasten locking element in direction of (arrow).
22. Re-install remaining components removed in reverse order.
23. Re-energise power supply of high voltage system Electrical system, hybrid93De-energising high-voltage system. [Note: Re-energising high-voltage system:Connect vehicle diagnostic testerSelect Guided Fault Finding modeUsing the Go to key, select the following menu items in successionFunction/component selectionBodyElectrical systemSelf-diagnosis compatible systems8C - Hybrid battery management -J8408C - Hybrid battery management, functions51 - Re-energise high-voltage system (Rep. gr. 93)]
24. ⚠ High voltage can cause fatal injury. Danger of severe or fatal injuries from electric shock. The high-voltage system may only be re-energised by a suitably qualified person (Audi high-voltage technician). The system may only be re-energised using the vehicle diagnostic tester via "“Guided Fault Finding”". The vehicle is then made ready for operation again by the qualified person (Audi high-voltage technician).The qualified person (Audi high-voltage technician) marks the vehicle by attaching the appropriate warning signs. — Switch on ignition.
25. Interrogate event memory of operating unit (Climatronic control unit J255) and erase any entries displayed ("“Guided Fault Finding”").
26. By way of the "“compressor run-in”" function, start up the electrical air conditioner compressor V470 in "“Guided Fault Finding”" mode for air conditioner and battery regulation.
27. Start up air conditioner after charging refrigerant circuit . [Note: Also observe notes on starting up air conditioner after charging Air conditioner with refrigerant R134a87General notes on air conditioning systems.]

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