2021 Audi e-tron Parking Brake Warning TSB

Owners of the 2021 Audi e-tron may experience a sporadic Audi e-tron parking brake warning in the instrument cluster when starting their vehicle. This warning is typically accompanied by the text "Parking brake fault" and indicates a potential issue with the electronic parking brake system.

Symptoms

If your 2021 Audi e-tron is affected, you may observe the following symptoms:

• A warning lamp for the electronic parking brake briefly illuminates in the instrument cluster.
• The text message "Parking brake fault" appears on the display.
• These symptoms primarily occur when starting the vehicle.

Fault Codes / DTCs

When diagnosing this issue, technicians may find the following Diagnostic Trouble Code (DTC) stored sporadically in the ABS control module, identified as J104 (address word 0003):

Technical Background

The root cause of the Audi e-tron parking brake warning and DTC U103100 is outdated software within the Anti-lock Braking System (ABS) control module. An updated software version has been implemented in production to prevent this condition in newer vehicles.

Repair Procedure Summary

To resolve the parking brake warning and DTC U103100, Audi dealerships will perform a software update on the affected control modules. The procedure involves the following steps:

1. Software Version Management (SVM) Update: Technicians will follow the instructions detailed in TSB 2011732, specifically the 00 Software Version Management (SVM) operating instructions.
2. Module Updates: The ABS control module (J104, address word 0003) and the suspension control module (J775, address word 0074) will be updated using the SVM action code 74A006.
3. Basic Settings: After the software update, basic settings for the electromechanical parking brake and the tire pressure monitoring system must be performed.
4. Post-Update Check: If the DTC U103100 persists in the ABS control module (J104) after the update, additional steps are required. This includes locking the vehicle, waiting for sleep bus mode to activate, reading the ABS memory log, deleting any remaining DTCs, and reevaluating the vehicle.

Required Software and Part Numbers

The software update involves specific part numbers and software versions for the ABS and suspension control modules:

Owner Action

If your 2021 Audi e-tron displays a Audi e-tron parking brake warning or the "Parking brake fault" message, it is recommended to schedule an appointment with an authorized Audi service center. The software update is typically covered under warranty for vehicles up to 48 months or 50,000 miles, whichever comes first. Certified Pre-Owned (CPO) vehicles may also be covered. If your vehicle is outside of warranty, this Technical Service Bulletin serves as informational guidance.