2022-2023 Audi A3, S3, RS 3 3rd Brake Light Warning TSB

Symptoms of the 3rd Brake Light Warning

Owners of 2022-2023 Audi A3, S3, and RS 3 models may observe a "3rd brake light warning" message displayed in the instrument cluster. Despite this warning, the 3rd brake light itself typically continues to operate as expected. Technicians have confirmed that the wiring for the 3rd brake light is usually in good condition, and the light functions normally.

A key characteristic of this issue is that the warning message will disappear after the ignition is switched off and then turned on again. However, it may reappear intermittently.

Fault Codes / DTCs

When diagnosing this condition, technicians will find the following Diagnostic Trouble Code (DTC) stored in the Electronic Central Electrical (BCM), specifically the J519 control unit (address word 0009):

• DTC B12C615: "Bulb for high-mount brake light open circuit/short circuit to B+_intermittent"

This DTC indicates a perceived electrical fault with the high-mount brake light, even when no physical fault exists.

Technical Background

Audi has identified that the root cause of this persistent Audi S3 3rd brake light warning and the stored DTC B12C615 is overly sensitive diagnostic software. The system incorrectly interprets normal operating conditions or minor electrical fluctuations as a fault, triggering the warning message and logging the DTC.

Important Warnings for Owners and Technicians

Audi Technical Service Bulletin 94 22 59 2067742/2 provides critical guidance:

• Do not replace components: Owners should be informed that no repairs are necessary at this time, and replacing any components for this condition will not resolve the concern. This prevents unnecessary parts replacement and charges.
• No capacitor replacement: There is no need to remove or replace the suppression capacitor C24 in the wiring harness for the 3rd brake light. This component is not the cause of the issue.

What Owners Should Do

If you experience an Audi S3 3rd brake light warning in your 2022-2023 Audi A3, S3, or RS 3, and the light is still working, you should contact your authorized Audi dealer. Explain the symptoms you are observing. The dealer will be able to confirm if your vehicle is affected by this known software sensitivity issue.

Audi is actively preparing a software solution to address this problem, which is expected to be available by the end of the first quarter of 2023, though this timeline is subject to change. While waiting for the software update, your dealer will create a PSS (Pending Service Solutions) record to document the concern. This ensures that your vehicle's issue is officially noted and that you will be informed when the permanent software fix is released.

It is important to note that this Technical Service Bulletin (TSB) 94 22 59 2067742/2 is informational and does not apply to any Audi warranty claims. If your 3rd brake light is genuinely inoperative, and not just showing a warning, a normal diagnostic procedure should be followed, as this TSB specifically addresses the scenario where the light functions despite the warning.

TSB Revision History

This bulletin, identified as 94 PSS and reference number 94 22 59 2067742/2, was initially published on August 10, 2022. It was revised on October 21, 2022, to update the header and include Model Year 2023 vehicles. This bulletin supersedes Technical Service Bulletin Group 94 number 22-57, which was dated August 9, 2022.

NHTSA ID: 10225556