2021-2025 Audi Q8/SQ8/RS Q8 Window Reversal TSB

Owners of 2021-2025 Audi Q8, SQ8, and RS Q8 models may experience an issue where a front or rear door window fails to close properly, reversing its direction and opening again. This behavior is addressed by Technical Service Bulletin (TSB) 2080696/1, released on January 28, 2026, which identifies a software-related problem within the vehicle's door control units.

This TSB provides a detailed procedure for dealerships to diagnose and resolve the Audi Q8 window reversal issue through a software update, ensuring proper window operation and preventing potential damage to high-voltage components during the repair process.

Symptoms

Owners may notice the following symptom:

• "When attempting to close one of the front or rear door windows using a window regulator switch, the window opens (reverses) again."

This indicates that the window's anti-pinch or safety reversal system is being triggered incorrectly, preventing the window from fully closing.

Fault Codes / DTCs

When diagnosing this issue, technicians may find a specific diagnostic trouble code (DTC) logged in the door control units. The primary fault code associated with this Audi Q8 window reversal problem is:

• B148754: "Motor for window regulator - no basic setting – passive/intermittent"

This DTC suggests that the window regulator motor's basic settings are either missing or intermittently failing, leading to the window reversal behavior.

Important Warnings for Owners

This TSB includes critical information regarding the repair process, especially for vehicles equipped with high-voltage components:

• High-Voltage Battery Safety: "To prevent the high-voltage battery from charging during the software update, the high-voltage charging cable on vehicles with high-voltage components must be unplugged BEFORE the SVM code is entered." This is crucial to protect both the vehicle's systems and the technician.
• Component Damage Risk: "Please note that charging the high-voltage battery during a software update can cause damage to the high-voltage components." Owners should be aware of this specific risk if the procedure is not followed correctly by the service center.

Diagnosis and Trigger Conditions

Workshop findings confirm that the customer's reported symptom can be reproduced. The presence of DTC B148754 in door control units with diagnostic addresses 0042, 0052, or others, confirms a software issue as the root cause. The problem stems from a changed target data container in production, indicating a software configuration discrepancy.

Before proceeding with the software update, technicians must verify that one of the following target data container (TDC) part numbers is present in the corresponding door control units:

• 4M8.909.872.D
• 4M8.909.872.E
• 4M8.909.872.F
• 4M8.909.872.G

If none of these TDC part numbers are found, the SVM code for the update cannot be run.

Repair Procedure Summary

The resolution for the Audi Q8 window reversal issue involves a software update to the affected door control units. The general procedure is as follows:

1. Prepare the Vehicle: For vehicles with high-voltage components, ensure the high-voltage charging cable is unplugged before proceeding with the software update to prevent potential damage.
2. Wake Up Door Control Units: Fully open and close all electric windows using their respective regulator switches. This step ensures that all door control units are active and ready for the update.
3. Verify TDC Part Numbers: Confirm that one of the specified TDC part numbers (4M8.909.872.D, 4M8.909.872.E, 4M8.909.872.F, 4M8.909.872.G) is present in the relevant door control units.
4. Perform Software Update: Use the "Flash" mode on the ODIS tester to enter SVM code 42A029. This will update all door control units simultaneously. Technicians must follow the instructions provided by the ODIS tester during this process.

Warranty Information

Audi's warranty policies apply to this TSB. If the vehicle is outside of its warranty period, this Technical Service Bulletin is for informational purposes only, meaning the repair may not be covered free of charge. Warranty claims are subject to review by Audi Warranty and must adhere to the Audi Warranty Policies and Procedures Manual.

Relevant codes for warranty claims include:

• Service Number: 6438
• Damage Code: 0039
• Labor Operations: 0151 0010 (Software update), 0151 0060 (Software update)

Additional Information for Owners

It is important for owners to understand that this software update may affect previous modifications made to the vehicle's software by third parties (e.g., tuning). The update might neutralize such modifications. If an owner declines the software update, they should be informed that this could lead to ongoing issues or restrictions with the use of the vehicle or individual components.

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Source: NHTSA ID: 11028463