2021-2023 Audi e-tron Electric Motor Leak TSB 2073858/8

Audi has released Technical Service Bulletin (TSB) 2073858/8 to address various warning messages and electric drive motor coolant leaks in 2021-2023 Audi e-tron vehicles. This TSB specifically covers issues such as a "Drive System/Electrical System Malfunction" message appearing in the instrument cluster and the diagnostic trouble code (DTC) P0AA600.

The bulletin highlights that internal coolant leaks can damage the electric drive motor, leading to these symptoms and fault codes. It provides detailed diagnostic and repair procedures for technicians to identify and resolve the issue.

Symptoms

Owners of affected 2021-2023 Audi e-tron models may observe one or more of the following symptoms:

• A "Drive System/Electrical System Malfunction" warning message displayed in the instrument cluster.
• Unusual noises or vibrations from the engine or transmission, described as jerking, vibrating, misfiring, or pinging.
• Functionality issues, including the vehicle not switching on, not connecting, or exhibiting general malfunction.
• Visible coolant leaks, particularly from the electric drive motor area, which may appear as a full coolant drip container or coolant leaking from the active chamber on the front or rear axle.

Fault Codes / DTCs

When diagnosing this issue, technicians may find the following diagnostic trouble code (DTC) stored in the Battery manager control module -J840- (address word 008C):

Code	Description	Module
P0AA600	Hybrid/EV Battery Voltage System Isolation	Battery manager control module -J840-

Diagnosis / Trigger Conditions

Diagnosis typically begins with the customer's complaint of a warning message or observed leak. During a workshop visit, the following conditions confirm the issue:

• The presence of DTC P0AA600, indicating a Hybrid/EV Battery Voltage System Isolation fault.
• An internal coolant leak detected on the electric drive motor. This can be identified by a full coolant drip container or coolant leaking from the active chamber on either the front or rear axle.

It is crucial to note that the electric drive motor is considered damaged due to an internal coolant leak only if these specific conditions are met. Technicians are advised to check the seal on the coolant expansion tank and re-secure it if necessary. Vehicles should never be operated without a correctly filled cooling system.

Repair Procedure Summary

The repair procedure focuses on identifying and rectifying the source of the coolant leak. The high-level steps include:

1. Check for Coolant Leaks: Thoroughly inspect the electric drive motor for any signs of internal coolant leakage. This involves checking the drip container and the active chambers on both the rear and front axles.
   • For the rear axle, inspect if the drip container is overflowing or empty. Coolant leaking from the active chamber is a key indicator, especially in vehicles with low mileage.
   • For the front axle, check for coolant leaking from the active chamber.
2. Evaluate Leak Severity: A few milliliters of coolant leakage from the resolver cover (Figure 3, item 1) is generally not considered a technical issue. However, no coolant should escape from the bores of the active chamber (Figure 3, item 2).
3. Replace Electric Drive Motor (if necessary): If an internal coolant leak is confirmed and causing damage, the electric drive motor(s) may need replacement. Specific labor operations are provided for replacing front or rear electric drive motors, or both for e-tron S models.
4. High-Voltage System Management: Deactivate and reactivate the high-voltage system as part of the repair process.
5. Battery Charge and Test Drive: Charge the battery and perform test drives both before and after the service procedure to confirm the repair's effectiveness.

Important Caution: The power electronics must not be replaced if the electric drive motor is only leaking. Refer to market-specific ETKA information for further guidance.

Required Tools or Parts

While no specific special tools are listed, the TSB outlines various labor operations and associated service numbers for warranty claims:

• Checking for Leaks:
  • Check electric drive motor for front axle for leaks: Labor Operation 9340 0199 (15 TU)
  • Check electric drive motor for rear axle for leaks: Labor Operation 9346 0199 (10 TU)
• Replacing Motors:
  • Replace front drive motor: Labor Operation 9340 55xx
  • Replace electric drive motor for rear axle: Labor Operation 9346 55xx
  • Replace 2 electric drive motors for rear axle, e-tron S: Labor Operation 9346 56xx
• System Operations:
  • Deactivate and activate the high-voltage system: Labor Operation 9310 835X
  • Charge battery: Labor Operation 2706 8950
  • GFF (Guided Fault Finding): Labor Operation 0150 0060
• Test Drives:
  • Test drive before service: No Allowance
  • Test drive after service: Labor Operation 0121 0004 (10 TU)

Owner Action

If your 2021-2023 Audi e-tron is displaying a "Drive System/Electrical System Malfunction" message, exhibiting unusual noises, or showing signs of a coolant leak, it is recommended to schedule an appointment with an authorized Audi service center. The Audi e-tron electric motor leak P0AA600 issue requires professional diagnosis and repair by trained technicians.

Warranty claims for this issue must adhere to the Audi Warranty Policies and Procedures Manual. If your vehicle is outside of warranty, this TSB serves as informational guidance for repairs.