2021-2023 Audi e-tron Electric Drive Motor Leak P0AA600

Audi has released Technical Service Bulletin (TSB) 2073858/5 to address an electric drive motor leak affecting various e-tron models. This TSB, issued on December 19, 2024, supersedes previous bulletin 24-29 dated November 7, 2024, and provides updated measures and warranty information for diagnosing and repairing this issue. The Audi e-tron electric motor leak can trigger critical warning messages and diagnostic trouble codes.

Symptoms

Owners of affected Audi e-tron vehicles may observe specific warnings in the instrument cluster. The primary symptom is a "Drive System/Electrical System Malfunction" message. This warning may not always be present during a technician's inspection, but it indicates a potential underlying issue. Additionally, a more severe message, "Electrical system: malfunction! Safely stop vehicle", may appear, urging immediate attention.

Fault Codes / DTCs

When an electric drive motor leak occurs, the vehicle's diagnostic system will typically store a specific fault code. The following Diagnostic Trouble Code (DTC) is associated with this condition:

Code	Description	Module
P0AA600	Hybrid/EV Battery Voltage System Isolation	Battery manager control module -J840- (address word 008C)

This DTC indicates an isolation fault within the high-voltage battery system, often a direct result of coolant leakage affecting the electric drive motor.

Diagnosis / Trigger Conditions

Technicians will investigate the presence of an internal coolant leak within the electric drive motor. This can be identified if the coolant drip container is found to be full, or if coolant is visibly leaking from the active chamber on either the front or rear axle. For rear axle leaks, an overflowing drip container indicates coolant leaking from the active chamber. If the drip container is empty, coolant may still be leaking from the active chamber, particularly in vehicles with low mileage.

It's important to note that a few milliliters of coolant leakage from the resolver cover (Figure 3, item 1 in the TSB) is considered normal and not a technical issue. However, no coolant should escape from the bores of the active chamber (Figure 3, item 2).

Important Warnings

Audi emphasizes several critical points for both technicians and owners:

• "Vehicles should never be operated without a correctly filled cooling system." Operating the vehicle with insufficient coolant can lead to further damage.
• "The power electronics must not be replaced if the electric drive motor is leaking." This is a crucial directive to prevent unnecessary and costly repairs. The focus should be on addressing the leak itself.
• If the power and control electronics for the electric drive must be replaced as a group, this must be billed separately according to warranty accounting instructions.

Repair Procedure Summary

The repair process for an Audi e-tron electric motor leak involves thoroughly checking for and localizing the source of the coolant leak. Technicians will inspect the electric drive motor for any signs of internal leakage. If an internal coolant leak is confirmed to be damaging the electric drive motor, the motor will require replacement. Before and after any work, the seal on the coolant expansion tank should be checked and re-secured to ensure the cooling system integrity.

Warranty and Labor Operations

This TSB provides detailed warranty claim information and labor operations for technicians. If the vehicle is outside of warranty, this bulletin serves as informational guidance only. Specific service numbers and damage codes are provided for different repair scenarios:

• Service Number 9340: For replacement of the front electric drive motor (Damage Code: 0050).
• Service Number 9346: For replacement of the rear electric drive motor (Damage Code: 0050).
• Service Number 9350: For replacement of the power and control electronics for electric drive (Damage Code: T055).

Labor operations include checking for leaks, replacing drive motors, replacing power and control electronics, deactivating and activating the high-voltage system, charging the battery, and performing test drives. All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual.

Owner Action

If your 2021-2023 Audi e-tron or e-tron Sportback displays a "Drive System/Electrical System Malfunction" message or you suspect an Audi e-tron electric motor leak, it is crucial to contact your authorized Audi dealership promptly. Do not ignore these warnings, as operating the vehicle with a coolant leak can lead to further damage. Your dealer will perform the necessary diagnostics and repairs according to TSB 2073858/5.

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Source: NHTSA ID: 11012533