2025 Audi A5/S5 Side Assist False Warning TSB 2078803/1

Audi has issued Technical Service Bulletin (TSB) 2078803/1 to address instances where the side assist system in certain 2025 Audi A5 and S5 models generates warnings without cause. This bulletin, released for publishing on July 31, 2025, provides a solution for owners experiencing these phantom alerts.

The core problem identified is that reflections within the bumper carrier can interfere with the side assist system's sensors. This interference leads to the system incorrectly detecting vehicles in the blind spot, causing the corresponding warning light in the exterior mirror to illuminate.

Symptoms

Owners of affected 2025 Audi A5 and S5 vehicles may observe the following symptoms related to the side assist system:

• The side assist system "issues warnings for no reason" regarding vehicles in the blind spot.
• The system may display a "vehicle in adjacent lane warning" or provide "vehicle in adjacent lane information" when no vehicle is present.
• The warning light in the exterior mirror on the corresponding side of the vehicle "lights up" without an actual obstacle.

These symptoms indicate that the side assist functionality "activates without cause," leading to unnecessary alerts.

Diagnosis and Trigger Conditions

Audi's workshop findings confirm that the complaint of false side assist warnings can typically be reproduced during diagnostic checks. The technical background points to reflections originating from the bumper carrier as the root cause of these erroneous detections. These reflections can trick the side assist sensors into believing there's an object in the blind spot when there isn't one.

Repair Procedure Summary

The repair outlined in TSB 2078803/1 involves modifying the bumper carrier to eliminate the reflections causing the false warnings. Technicians will close off specific openings on both sides of the bumper carrier using aluminum adhesive tape. This physical barrier prevents light from reflecting off internal surfaces and interfering with the side assist sensors.

For vehicles equipped with a towing bracket, the repair focuses on sealing the bumper carrier opening on the left side, as illustrated in Figure 1 of the bulletin. For vehicles without a towing bracket, the procedure is more extensive, requiring the sealing of openings on both the side and top of the bumper carrier, as depicted in Figures 2 and 3.

Important Repair Notes

Technicians performing this repair must adhere to specific instructions to ensure proper functionality and prevent future issues:

• "When attaching the aluminum adhesive tape, please ensure that there is a small drainage opening at the bottom so that water can drain."
• "For the version without a towing bracket, please also seal off the openings on the top of the bumper carrier (see figures 2 and 3)."

These steps are critical to prevent water accumulation and ensure the long-term effectiveness of the repair.

Warranty Information

Warranty claims for this repair should be submitted in accordance with the Audi Warranty Policies and Procedures Manual. The relevant codes for this service are:

• Service Number: 9635
• Damage Code: 0010

Labor operations include removing and installing the rear bumper cover (Labor Code 6369 1900) and modifying the bumper carrier (Labor Code 6350 5099), which is allotted 10 Time Units (TU). If the vehicle is outside of its warranty period, this Technical Service Bulletin serves as informational guidance.

Owner Action

If you own a 2025 Audi A5 or S5 and are experiencing a "2025 Audi A5 side assist warning" or false blind spot alerts, it is recommended to contact your authorized Audi dealership. Inform them about the symptoms you are observing and mention Technical Service Bulletin 2078803/1. The dealership will be able to diagnose the issue and perform the necessary repair using aluminum adhesive tape to resolve the false warnings.

NHTSA ID: 11021484