2022-2024 Audi Airbag Warning Light On: DTC B13BCF2

Owners of 2022-2024 Audi vehicles may experience an illuminated airbag warning light in the instrument cluster. This condition is often accompanied by the diagnostic trouble code (DTC) B13BCF2, which indicates a "Multiple collision brake No function" fault stored in the airbag control module (J234).

This Technical Service Bulletin (TSB) 2056406/4, superseding earlier bulletin 22-84, provides diagnostic steps and a repair procedure to address the Audi B13BCF2 airbag light issue.

Symptoms

The primary symptom owners will notice is the persistent illumination of the airbag warning light on the dashboard. This light will remain on until the DTC B13BCF2 is manually cleared from the airbag control module.

Fault Codes / DTCs

When diagnosing this issue, technicians will find the following diagnostic trouble code:

Code	Description	Module
B13BCF2	Multiple collision brake No function	Airbag control module (J234, address word 0015)

This DTC can be present as active/static or passive/sporadic.

Diagnosis and Trigger Conditions

The "Multiple collision brake" system is managed by the ABS control module (J104) and is an integral part of the Anti-lock Braking System (ABS) and Electronic Stability Control (ESC) functionality. If the ABS control module detects an error related to the ABS/ESC system, the "Multiple collision brake" feature is deactivated. This deactivation triggers both the ESC and airbag warning lights to illuminate, and the DTC B13BCF2 is stored in the airbag control module.

It's important to note that the airbag warning light acts as an indicator that the "Multiple collision brake" has been deactivated. The presence of the Audi B13BCF2 airbag light is a symptom, not the root cause of the deactivation itself. If the brake system error is temporary and does not recur, the ESC warning light will turn off after the next ignition cycle. Any DTCs stored in the ABS control module will clear automatically after 40 ignition cycles if no further issues are detected.

Repair Procedure Summary

The repair process for the Audi B13BCF2 airbag light involves a systematic diagnostic approach:

1. Connect the vehicle to the ODIS Service system and perform a Guided Fault Finding (GFF) scan.
2. Address any other DTCs found that could have caused the ABS/ESC system to deactivate. The root cause of these DTCs must be eliminated first.
3. Once any underlying issues are resolved, clear the DTC B13BCF2 from the airbag control module.
4. If no other DTCs were present that could explain the ABS/ESC deactivation, proceed directly to erasing DTC B13BCF2 in the airbag control module.
5. If DTC B13BCF2 cannot be cleared initially, disconnect the scan tool from the Diagnostic Link Connector (DLC). Park the vehicle, turn off the ignition, and lock the vehicle. After 30 minutes, attempt to clear the DTC again.
6. After successfully clearing B13BCF2, road test the vehicle to confirm that no faults return.
7. If the customer experiences this concern again, an immediate GFF scan should be performed to identify the recurring root cause.

Important Warnings

Owners and technicians should be aware of a critical note regarding this issue:

• Replacing the airbag control module does not solve this issue. Claims for replaced parts will be subject to review, indicating that this is a diagnostic and software-related problem, not a hardware failure of the airbag control module itself.

Warranty Information

This service is covered under Audi's warranty policies for vehicles up to 48 months or 50,000 miles. For Audi Certified Pre-Owned (CPO) vehicles, coverage is under claim type G10, requiring owner verification. If the vehicle is outside of warranty, this Technical Service Bulletin serves as informational guidance only.

The Service Number associated with this bulletin is 6953, and the Damage Code is 0039. Diagnostic time for GFF is 0150 0000 (Max 50 TU), with road tests before (0121 0002, 0 TU) and after (0121 0004, 10 TU) the service procedure.

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Source: NHTSA ID 10238396