2021-2023 Audi e-tron Electric Motor Leak & P0AA600 TSB

Audi has issued Technical Service Bulletin (TSB) 2073858/8 to address various warning messages in the instrument cluster and electric motor coolant leaks, specifically related to Diagnostic Trouble Code (DTC) P0AA600, for certain 2021-2023 Audi e-tron vehicles. This bulletin provides guidance for technicians to diagnose and repair these conditions, particularly focusing on the Audi e-tron electric motor leak.

Revision History

This TSB, identified as 2073858/8, has undergone several revisions:

• Revision 8 (May 14, 2025): Revised Service information, including updated ETKA details.
• Revision 7 (February 20, 2025): Revised Warranty information, specifically updating labor operations.
• Revision 6 (January 23, 2025): Revised the title of the bulletin.

Symptoms and Owner Observations

Owners of affected Audi e-tron vehicles may experience a range of symptoms and warning messages. The primary customer complaint involves a "Drive System/Electrical System Malfunction" message appearing in the instrument cluster. This message may be accompanied by the verbatim warning: "Electrical system: malfunction! Safely stop vehicle".

Other reported complaints related to engine operation in electro-drive mode include noises and vibrations such as jerking, vibrating, noise, or pinging. Functionality issues like misfire, no function, the system not switching on or connecting, or being unable to switch on or activate are also noted. Transmission-related complaints include issues with control operation, power distribution, and leaks, including the vehicle not being watertight.

Diagnostic Findings and Fault Codes

During a workshop visit, technicians may find the following:

• DTC P0AA600: This Diagnostic Trouble Code, described as "Hybrid/EV Battery Voltage System Isolation," is stored in the Battery manager control module -J840- (address word 008C).
• Internal Coolant Leak: An internal leak may be observed, indicated by a full coolant drip container or coolant leaking from the active chamber on either the front or rear electric drive motor.

This condition arises from the electric drive motor being damaged due to an internal coolant leak.

Important Warnings for Owners and Technicians

Audi provides critical advisories regarding this issue:

• It can only be assumed that the electric drive motor is damaged due to an internal coolant leak if DTC P0AA600 is present and/or an internal leak is determined on the electric drive motor.
• Vehicles should never be operated without a correctly filled cooling system.
• Caution: The power electronics must not be replaced if the electric drive motor is leaking. Technicians should consult market-specific ETKA information.
• 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 service procedure outlined in TSB 2073858/8 focuses on checking for and localizing the source of the coolant leak. Before any work, the seal on the coolant expansion tank should be checked and re-secured. It is crucial that vehicles are not operated without a correctly filled cooling system.

Technicians will inspect both the rear and front axles for leaks:

• Rear Axle Inspection: If the drip container is overflowing, coolant is leaking from the active chamber. If the drip container is empty, coolant is still leaking from the active chamber, particularly in vehicles with low mileage. Figure 2 in the TSB illustrates the drain plug (1) for reference.
• Front Axle Inspection: Coolant leaking from the active chamber is also a sign. Figure 3 shows the resolver cover (1) and active chamber (2). It notes that a few milliliters of coolant leakage from the resolver cover is not a technical issue, and no coolant should escape from the active chamber bores.

This diagnostic and repair process is crucial to address the Audi e-tron electric motor leak.

Warranty Information

Warranty claims for this issue must comply with the Audi Warranty Policies and Procedures Manual. If the vehicle is outside of its warranty period, this Technical Service Bulletin serves as informational guidance only.

Labor Operation	Description	Time Units (TU)
9340 0199	Check electric drive motor for front axle for leaks	15 TU
9346 0199	Check electric drive motor for rear axle for leaks	10 TU
9340 55xx	Replace front drive motor	See SRT
9346 55xx	Replace electric drive motor for rear axle	See SRT
9346 56xx	Replace 2 electric drive motors for rear axle, e-tron S	See SRT
9310 835X	Deactivate and activate the high-voltage system	See SRT
2706 8950	Charge battery	See SRT
0150 0060	GFF (Guided Fault Finding)	Time stated
No Allowance	Test drive before the service procedure	0 TU
0121 0004	Test drive after the service procedure	10 TU

Note: SRT refers to Standard Repair Time with associated operations. Damage Code for motor replacement is 0050.

NHTSA ID: 2073858/8