2021-2024 Audi e-tron ABS Module No Communication TSB

Symptoms of the ABS/ESC Control Unit Issue

Owners of affected 2021-2024 Audi e-tron models may notice several issues related to the braking system. The primary concerns reported include reduced braking assistance, which can impact vehicle safety and performance. Additionally, various warning lamps may illuminate in the instrument cluster, alerting the driver to a system malfunction. These symptoms indicate a problem with the vehicle's Anti-lock Braking System (ABS) and Electronic Stability Control (ESC).

Diagnostic Trouble Codes (DTCs)

When diagnosing this issue, technicians will typically find that the ABS/ESC Control unit -J104- (Diagnostic address 0003) cannot be reached in communication. This communication failure is often accompanied by specific Diagnostic Trouble Codes (DTCs) stored in the vehicle's system:

• U012100 (Symptom Code 19875): "ABS Control Module no communication"
• P060A00: "Control module internal processor monitoring malfunction"

These codes confirm the communication breakdown with the ABS control module, which is central to the Audi e-tron ABS communication problem.

What Causes the ABS/ESC Communication Fault

The technical background for this issue indicates that the control unit -J104- may perform an unexpected restart. Following this restart, the electromechanical brake servo remains in a hydraulic fallback level, and critical bus communication ceases. This interruption in communication leads to the display of driver messages from other vehicle systems, signaling a fault. Audi notes that this restart is a rare occurrence.

Important Warnings for Owners and Technicians

Audi has issued a crucial notice regarding this issue, emphasizing the following:

• Do not replace any component.
• Any control unit replacement attempted for this concern may be denied under warranty.
• A permanent software solution is currently under development and will be released in a future revision of this bulletin.

This warning is critical for addressing the Audi e-tron ABS communication issue correctly and avoiding unnecessary part replacements.

Repair Procedure Summary

Until a permanent software solution is available, the current procedure for addressing the Audi e-tron ABS communication fault involves a temporary reset. The steps are similar for vehicles with ABS/ESC control unit -J104- software versions SW 2XX and SW 321, though the anticipated software update timelines differ:

1. Disconnect the 12V battery from the vehicle for 5 minutes.
2. Reconnect the battery and then check the accessibility of the control unit -J104- in the diagnostic system.
3. If present, delete any intermittent DTCs, including P060A00 "Control module internal processor monitoring malfunction," from all control units.
4. After cycling the ignition off and back on, recheck control unit -J104- for communication.

If communication is restored and no other DTCs are present in diagnostic address 0003, the vehicle can be released. Audi plans to release a software solution for SW 2XX vehicles in the second quarter of 2024 and for SW 321 vehicles in the third quarter of 2024.

Warranty Information

This service is covered under Audi's warranty program, specifically Claim Type 110, for vehicles up to 48 months or 50,000 miles. The claim comment for this procedure should reference TSB 2072977/1. The labor operation for disconnecting and reconnecting the battery is 4770 4999, allotted 20 time units (TU), with a damage code of 0040. Diagnostic time (GFF 0150 0000) is capped at 50 TU. Road tests before and after the service procedure are not allotted additional time units.

NHTSA ID: 10250553