Removing and installing power and control electronics for electric drive — AUDI

🧭 Before you start

Fits: Audi A8 D4 (4H, 2010–2017)

Don't miss

• Check that the red warning label on the power and control electronics for electric driveJX1 is present and take care not to damage it.
• Catch escaping coolant using a suitable container.
• High-voltage wires can only be connected and secured in specified sequence.Connect and lock high-voltage wire connectors in reverse sequence to removal.

🔧 Engine codes this applies to

🔩 Torque settings

Values can differ between engine variants — check the code stamped on your block.

ℹ️ Always cross-check the exact figure against your vehicle's factory manual before final tightening — a wrong torque can damage the engine. These values are extracted from workshop data and may not cover every variant or revision.

📋 Procedure

1. ⚠ Working on vehicles with high-voltage wiring:Do not support yourself or tools on high-voltage wiring or associated components --> this can damage the insulation. High-voltage wiring must not be excessively bent or kinked --> this can damage the insulation. 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. — De-energise high-voltage system. [Note: De-energising high-voltage system:Connect vehicle diagnostic testerSelect Guided Fault Finding modeUsing the Go to button, select the following menu options in succession:Selecting function/componentBodyElectrical systemSelf-diagnosis-compatible systems8C - Hybrid battery management -J8408C - Hybrid battery management, functions51 - De-energise high-voltage system (Rep. gr. 93)]
2. ⚠ High voltage can cause fatal injuryDanger of severe or fatal injuries from electric shock 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 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 are then stored in a safe place by the qualified person.The qualified person (Audi high-voltage technician) marks the vehicle by attaching the appropriate warning signs. — Disconnect 12 V batteries Electrical system27Battery; Disconnecting and connecting battery.
3. Remove front left headlight Electrical system94Headlights; Removing and installing headlights.
4. Remove upper longitudinal member General body repairs, exterior50Lock carrier; Exploded view - lock carrier.
5. Unplug connector to bonnet lock (left-side) above cover of power and control electronics for electric driveJX1.

6. Remove bolts (arrows) on cover (1) and take cover off power and control electronics for electric driveJX1(2).
7. Check that the red warning label on the power and control electronics for electric driveJX1 is present and take care not to damage it.
8. Slide locking mechanism (5) for high-voltage wire for electrical air conditioner compressor P3(3) in direction of (arrow).
9. Disconnect high-voltage wire for electrical air conditioner compressor P3(2) from power and control electronics for electric driveJX1 as described below.
10. Use release tool T40258 to release and unplug high-voltage connector for high-voltage wire for electrical air conditioner compressor P3 from right side.
11. ⚠ Do not use excessive force when releasing and unplugging the high-voltage connectors.To release the catch, first press gently on the high-voltage connector you wish to unplug and then pull the connector upwards.Never use levering tools to release and unplug the high-voltage connectors.Only unplug high-voltage connectors by pulling them upwards. Do NOT rotate or tilt them; this could damage the coding on the high-voltage wires. — Push locking mechanism (4) in direction of (arrow).
12. As described below, release and unplug high-voltage wiring harness for hybrid batteryPX1/high-voltage wiring harness for drive motorPX2(1) and (2) from power and control electronics for electric driveJX1.
13. From left side, use release tool T40258 to release and unplug high-voltage connectors for high-voltage wiring harness for hybrid batteryPX1/high-voltage wiring harness for drive motorPX2.
14. ⚠ Do not use excessive force when releasing and unplugging the high-voltage connectors.To release the catch, first press gently on the high-voltage connector you wish to unplug and then pull the connector upwards.Never use levering tools to release and unplug the high-voltage connectors.Only unplug high-voltage connectors by pulling them upwards. Do NOT rotate or tilt them; this could damage the coding on the high-voltage wires. — Place the high-voltage wiring harness for hybrid batteryPX1(1), the high-voltage wiring harness for drive motorPX2 and the high-voltage wire for electrical air conditioner compressor P3(2) on a cover on the engine.
15. Release and unplug connector (2) on power and control electronics for electric driveJX1(1).
16. Remove bolt (arrow) on bracket (front) (1).
17. Remove bolts (arrows) on bracket (rear) (1).
18. Unscrew nuts (arrows) on terminal 30 wiring junction 2TV22(1) and move terminal 30 wiring junction 2TV22(1) to side.
19. Unfasten potential equalisation line (2) on body (3).
20. Unscrew securing nut for B+ wire (9 Nm) (1) and pull B+ wire off threaded connection on power and control electronics for electric driveJX1(2). — 9 Nm (6.6 lb-ft)
21. Clamp off both coolant lines (3) and (4) with hose clamps up to 25 mm3094(2) and (5).
22. Open and pull off both hose connectors (6). [Note: Catch escaping coolant using a suitable container.]
23. Lift power and control electronics for electric driveJX1(1) upwards slightly.
24. Disconnect breather hose.
25. Lift power and control electronics for electric driveJX1 upwards out of vehicle (guide potential equalisation line out while doing so).
26. Remove potential equalisation line on power and control electronics for electric driveJX1.
27. Remove bolts (2) and take bracket (front) (1) off power and control electronics for electric driveJX1.
28. Remove bolts (2) and take bracket (rear) (1) off power and control electronics for electric driveJX1. [Note: Check the contact surfaces of the potential equalisation lines prior to installation.The contact surfaces must be clean and free from rust and grease.Otherwise, repair the contact surfaces using the contact surface cleaning setVAS 6410Electrical system; General information97Cleaning contact surfaces.]
29. ⚠ Working on vehicles with high-voltage wiring:Do not support yourself or tools on high-voltage wiring or associated components --> this can damage the insulation. High-voltage wiring must not be excessively bent or kinked --> this can damage the insulation. 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. — Connect high-voltage wires according to their coding .
30. Tighten all screw connections to the tightening torques specified . [Note: High-voltage wires can only be connected and secured in specified sequence.Connect and lock high-voltage wire connectors in reverse sequence to removal.]
31. Check that the red warning label on the power and control electronics for electric driveJX1 is present and take care not to damage it.
32. Re-energise high-voltage system. [Note: Re-energising high-voltage system:Connect vehicle diagnostic testerSelect Guided Fault Finding modeUsing the Go to button, select the following menu options in succession:Selecting function/componentBodyElectrical systemSelf-diagnosis-compatible systems8C - Hybrid battery management -J8408C - Hybrid battery management, functions51 - Re-energise high-voltage system (Rep. gr. 93)]
33. ⚠ 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. — Bleed low-temperature circuit 19Cooling system/coolant; Draining and filling coolant.
34. Select Guided Fault Finding mode.
35. Using the Go to button, select the following menu options in succession:

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