2022-2024 Audi Exterior Lighting Warning TSB

Owners of certain 2022-2024 Audi A3, S3, RS 3, and Q4 models may encounter an Audi S3 exterior lighting warning displayed in the instrument cluster. This warning can appear for the exterior lighting or adaptive light system, even when all lighting functions appear to be working correctly.

This concern is addressed by Audi Technical Service Bulletin (TSB) 94 24 83 2074786/1, issued on July 31, 2024. The TSB indicates that the diagnostic software in the onboard supply control unit J519 (address 0009) is too sensitive, leading to the erroneous warning.

Symptoms

The primary symptom is a verbatim message: "A warning lamp for the exterior lighting or adaptive light is displayed in the instrument cluster." Despite this warning, the lighting system typically appears to be functioning as it should, with all lights working normally. This suggests a false positive rather than a true hardware malfunction.

Fault Codes / DTCs

When this Audi S3 exterior lighting warning occurs, the following Diagnostic Trouble Codes (DTCs) may be stored in the onboard supply control unit J519 (address 0009):

DTC Code	Description	Module
B126A29	Light switch Range/Performance	J519
U112100	Data bus missing message	J519
U110B00	Light switch no communication	J519

Diagnosis / Trigger Conditions

The root cause of this issue is identified as overly sensitive diagnostic software within the J519 onboard supply control unit. This sensitivity can trigger the warning lamp and store the associated DTCs even when there is no actual fault with the lighting system's hardware. Audi has planned an optimized software solution for production week 25/25 to address this sensitivity in future vehicles.

Important Warnings for Owners

• Specific DTC U110B00 Condition: If only DTC "U110B00 Light switch no communication" is stored without the other entries (B126A29 or U112100), the cause may be a loose connector, a pin that has been pushed back, or a wiring problem. In this specific scenario, the resolution outlined in this TSB may not apply, and further diagnosis for a physical connection issue would be necessary.
• Warranty Claim Conditions: This TSB emphasizes that the repair should only be carried out if all criteria (model/type, chassis number, engine/motor and gearbox code, PR numbers, part number, software version, code, etc.) apply exactly. If the solution is applied when criteria are not met, it will not resolve the problem, and repeat repairs may be necessary. In such cases, Audi may reject the warranty claim and charge back the cost of parts.

Repair Procedure Summary

This TSB, 94 24 83 2074786/1, supersedes and closes a previous issue identified as PSS 20373612, which also related to headlight warnings and DTCs B126A29 and U110B00 stored in the 09 module. The repair procedure for the current Audi S3 exterior lighting warning is straightforward and involves the following steps:

1. Verify the Complaint: Technicians must first confirm that the situation matches the description of the warning lamp for exterior lighting or adaptive light being displayed, and that all lighting functions are working as expected.
2. Clear the Warning: Pressing the "AUTO" button in the vehicle will cause the warning lamp to go out. Simultaneously, the stored DTC entry will change from active to intermittent.
3. Delete DTCs: Once the DTC has changed to intermittent, it can then be deleted from the control unit's memory.

Warranty Information

For vehicles still under warranty, this repair can be claimed using the following information:

• Claim Type: If the vehicle is outside of any warranty, this Technical Service Bulletin is informational only, meaning the repair may not be covered.
• Service Number: 9405
• Damage Code: 0040
• Labor Operations: Service light switch (9405 4199) and GFF / Guided Functions (0150 0010 for diagnostic time, 0150 0060 for labor according to diagnostic log).
• Claim Comment: As per TSB 2074786/1.

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

Required Parts and Tools

No specific parts or special tools are required for this particular repair procedure, as it primarily involves a diagnostic and software interaction.

Owner Action

If your 2022-2024 Audi A3, S3, RS 3, or Q4 is displaying an Audi S3 exterior lighting warning as described, and your lights appear to be functioning normally, it is recommended to contact an authorized Audi service center. They can perform the diagnostic check and apply the simple procedure outlined in TSB 94 24 83 2074786/1 to clear the warning and associated DTCs.

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Source: NHTSA ID: 10255315, TSB ID: 94-24-83-2074786/1