2025-2026 Audi A5/A6 Side Assist Warning TSB 2078803/3

Symptoms of False Side Assist Warnings

Owners of certain 2025-2026 Audi A5, S5, and A6 vehicles may experience the side assist system issuing warnings for no reason. This manifests as the light in the exterior mirror on the corresponding side of the vehicle lighting up, even when no vehicle is present in the blind spot. Customers report issues such as "assistance systems, comfort controls -> lane change assistance -> vehicle in adjacent lane warning" or "assistance systems, comfort controls -> lane change assistance -> vehicle in adjacent lane information." The core complaint is that the side assist system "issues warnings for no reason" about vehicles in the blind spot.

Technical Background

Audi has identified that the root cause of these unwarranted side assist warnings is reflections occurring within the bumper carrier. These reflections can interfere with the side assist sensors, causing them to incorrectly detect objects or vehicles in the blind spot, leading to false alerts. Workshop findings confirm that the complaint can usually be reproduced, indicating a consistent underlying issue with the side assist system's functionality.

Revision History of TSB 2078803/3

Technical Service Bulletin 2078803/3 has undergone several revisions since its initial publication:

• Revision 1 (July 31, 2025): Initial publication of the bulletin.
• Revision 2: Included a revised Condition section, an updated model table, and modifications to the Service section, including changes to images.
• Revision 3: Revised the header of the bulletin and added additional models to the scope.

Repair Procedure Summary

Technical Service Bulletin (TSB) 2078803/3 outlines a detailed repair procedure to eliminate the reflections within the bumper carrier that cause the false Audi A5 A6 side assist warning. The repair involves closing specific openings on both sides of the bumper carrier using specialized caps or aluminum adhesive tape. The procedure is as follows:

1. Preparation: The first step requires the removal and subsequent reinstallation of the rear bumper cover to gain access to the bumper carrier.
2. Addressing Vehicles with Towing Bracket: For Audi A5, S5, and A6 models equipped with a towing bracket, technicians must close off the openings on both the left and right sides of the bumper carrier. This is achieved using part number 8B3.907.753.A. Figure 1 in the TSB visually demonstrates the left side of a bumper carrier closed with this specific cap for a version with a towing bracket.
3. Addressing Vehicles without Towing Bracket: For vehicles not equipped with a towing bracket, different parts are utilized. The left side opening of the bumper carrier is closed with part number 8B3.907.753, while the right side uses part number 8B3.907.754. Figure 2 illustrates the left side of a bumper carrier closed with a cap for a version without a towing bracket.
4. Sealing Top Openings (Vehicles without Towing Bracket): An additional critical step for versions without a towing bracket involves sealing the openings located on the top of the bumper carrier. This is done using commercially available aluminum adhesive tape. Figure 3 provides a visual reference, showing the left side of the bumper carrier with the upper opening securely closed using aluminum adhesive tape.
5. Final Reassembly: After all necessary openings are sealed, the rear bumper cover is reinstalled, completing the repair.

Required Tools and Parts

To perform the repair described in TSB 2078803/3, specific parts are required, depending on the vehicle's configuration:

• For vehicles equipped with a towing bracket:
  • Part number 8B3.907.753.A (used for both the left and right sides of the bumper carrier).
• For vehicles without a towing bracket:
  • Part number 8B3.907.753 (for the left side of the bumper carrier).
  • Part number 8B3.907.754 (for the right side of the bumper carrier).
  • Commercially available aluminum adhesive tape (for sealing top openings).

Warranty Information

This Technical Service Bulletin provides guidance for warranty claims related to the Audi A5 A6 side assist warning issue. If the vehicle is outside of its warranty period, this TSB is considered informational only, meaning the repair may not be covered under warranty. For in-warranty repairs, the following codes and labor operations are relevant:

• Service Number: 9635
• Damage Code: 0010
• Labor Operations:
  • 6369 1900: This operation covers the removal and installation of the rear bumper cover. Technicians should refer to the Service Repair Time (SRT) guide for associated operations.
  • 6350 5099: This operation is for modifying the bumper carrier, which includes the sealing process. It is estimated to take 10 Technical Units (TU).

All warranty claims submitted for payment must adhere strictly to the Audi Warranty Policies and Procedures Manual and are subject to review and audit by Audi Warranty. The claim comment should explicitly reference "As per TSB 2078803/3."

Important Warnings

NOTICE: For vehicles that are not equipped with a towing bracket, it is crucial to also seal off the openings located on the top of the bumper carrier. This additional step requires the use of commercially available aluminum adhesive tape, as depicted in Figure 3 of the TSB. Failing to seal these specific openings may prevent the complete resolution of the Audi A5 A6 side assist warning issue and could lead to continued false alerts from the side assist system.

Owner Action

If you own a 2025 Audi A5 or S5, or a 2026 Audi A6, and are experiencing an Audi A5 A6 side assist warning where the system issues warnings for no reason, you should contact your authorized Audi dealership. Provide them with the details of your vehicle's symptoms and reference Technical Service Bulletin 2078803/3. The dealership will be able to diagnose the issue and perform the necessary repair to resolve the false side assist warnings.

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Source: NHTSA ID: 11028438