2025-2026 Audi Loose Wheel / Tire Pressure Warning TSB

Symptoms

Owners of affected Audi vehicles, including the 2026 Audi A6, may observe an active "loose wheel or tire pressure warning" message. This warning may appear on its own or in conjunction with other messages on the instrument cluster. Dealership technicians have confirmed that this complaint can be reproduced, and various diagnostic trouble codes (DTCs) may be stored in the vehicle's memory.

Diagnosis / Trigger Conditions

Audi Technical Service Bulletin 2077226/8 indicates that the loose wheel warning is being addressed with increased software robustness, with a measure planned for Q2 2026. If the software updates are not yet available, or if the warning persists after an update, technicians should follow several diagnostic aids:

• Software Update: Ensure the vehicle's software is updated to the latest version, including any relevant campaigns or other TSBs.
• DTC Checks: Examine control unit addresses 812C, 0003, and 0065 for any relevant DTCs. These addresses are key areas where diagnostic information related to wheel and tire systems is stored.
• Wheel Balancing/Swapping: If DTCs are logged for individual wheels or all four, performing wheel balancing or swapping tires may help identify or resolve the issue.
• Vibration Sources: Inspect the vehicle for other potential sources of vibration, such as issues with brake discs or suspension links.
• Sensor Integrity: Verify that the speed sensors and sensor rings for the affected wheel are clean and functioning correctly. These components are crucial for accurate tire pressure monitoring and wheel speed detection.
• Guided Fault Finding: If there are problems with the overall availability of the system, technicians should correct these issues using Guided Fault Finding procedures.
• Cross-System DTCs: Check for DTCs in other control units and consult specific TSBs that might be related to the loose wheel warning, especially if the warning appears with other messages in the instrument cluster.

It is important to note that loose wheel and tire pressure messages can sometimes be a symptom of other underlying vehicle issues. The primary cause of the fault should always be identified and rectified first.

Repair Procedure Summary

The primary repair involves performing a software update. This update is described in TSB 2079690, specifically referencing software version 00 Combined software update 03.10.00/C (28.13.01) KD2. The service procedure includes connecting a battery charger to maintain voltage during the update process. Technicians will perform all necessary preliminary and follow-up work, including the bus sleep cycle, calibration drives, and any additional work required for the software update.

In cases where a flash abort occurs during the software update, additional attempts may be necessary. The goal is to ensure the vehicle's systems receive the updated software to improve the robustness against the Audi A6 loose wheel warning.

Important Warnings

If your vehicle is outside of its warranty period, this Technical Service Bulletin is for informational purposes only. This means that any diagnostic or repair costs may not be covered by Audi.

Warranty Information

For vehicles under warranty, claims are processed according to Audi's policies. The relevant information for warranty claims related to this TSB 2077226/8 includes:

• Service Number: 4545
• Damage Code: KD02
• Labor Operations:
  • 0151 0010: Software update, including connecting a battery charger (refer to SRT for associated operations).
  • 0151 0040: Fixed rate for software update, including all required preliminary and follow-up work (130 TU).
  • 0150 9999: Additional attempts after a flash abort, with 50 TU claimable per documented attempt.

All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual and are subject to review by Audi Warranty.

Revision History

This Technical Service Bulletin has undergone several revisions to provide the most current information:

• Revision 8: Updated service information.
• Revision 7 (January 28, 2026): Revised header to add models.
• Revision 6 (December 18, 2025): Revised header to add model years, updated the condition section with a revised model table, updated service verbiage, and revised warranty labor operations.

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Source: NHTSA ID: 11031008