2023-2026 Audi Airbag Warning Light TSB B13BCF2

Symptoms

Owners of affected Audi vehicles may observe the following:

• The "airbag warning light is illuminated in the instrument cluster."
• The ESC warning light may also be illuminated.

These warning lights indicate a potential issue with the vehicle's safety systems, specifically related to the "Multiple collision brake" function.

Fault Codes / DTCs

When diagnosing this issue, technicians will find the following Diagnostic Trouble Code (DTC) stored in the airbag control module (J234):

• B13BCF2: Multiple collision brake No function

This DTC can be active/static or passive/sporadic. The presence of B13BCF2 in the airbag control module is the primary indicator for this specific concern.

Technical Background

The "Multiple collision brake" system is managed by the ABS control module (J104) and is an integral part of the ABS/ESC functionality. If the ABS control module detects an error relevant to the ABS/ESC system, the "Multiple collision brake" is automatically deactivated. This deactivation triggers the illumination of both the ESC and airbag warning lights in the instrument cluster, and DTC B13BCF2 is stored in the airbag control module.

It's important to note that the airbag warning light is a symptom, not the root cause. If the underlying brake system error is passive or sporadic and does not recur, the ESC warning light will typically turn off after the next ignition cycle. Any DTCs stored in the ABS control module will clear themselves after 40 ignition cycles if not detected again. However, the Audi e-tron airbag warning light will remain on permanently until DTC B13BCF2 in the airbag control module is manually cleared. The "Multiple collision brake" will also stay deactivated as long as DTC B13BCF2 is present.

Important Warnings

Audi explicitly states the following regarding this issue:

• "Replacing the airbag control module does not solve this issue. Claims for replaced parts will be subject to review."

This means that the airbag control module itself is not the faulty component, and replacing it will not resolve the underlying problem causing the Audi e-tron airbag warning light to illuminate.

Diagnosis and Repair Procedure Summary

Addressing the illuminated airbag warning light and DTC B13BCF2 involves a specific diagnostic and repair process:

1. Connect and Scan: The vehicle must be connected to ODIS Service, and a Guided Fault Finding (GFF) scan performed.
2. Identify Root Cause: If other DTCs are present that could have caused the deactivation of the ABS/ESC functionality, follow the GFF instructions to determine and eliminate the root cause of those DTCs first.
3. Clear DTC B13BCF2: Once any underlying root causes are resolved, or if no other DTCs were present, manually clear DTC B13BCF2 from the airbag control module.
4. Persistent DTC: If DTC B13BCF2 cannot be cleared immediately, the scan tool should be disconnected from the Diagnostic Link Connector (DLC). The vehicle should then be parked, the ignition switched off, and the vehicle locked. After 30 minutes, attempt to clear the DTC again.
5. Verification and Release: Once B13BCF2 is successfully cleared, the vehicle should be road-tested to verify that no faults return. If no faults reappear, the vehicle can be released to the customer without further repairs.
6. Recurrence: If the customer experiences this concern again, an immediate vehicle scan with GFF should be performed to determine the root cause.

This procedure, identified by TSB 2056406/5, focuses on correctly diagnosing the underlying ABS/ESC issue rather than directly replacing components related to the airbag system.

Warranty Information

This Technical Service Bulletin (TSB) is covered under Audi's New Vehicle Limited Warranty for up to 48 months or 50,000 miles, whichever comes first. For Audi Certified Pre-Owned (CPO) vehicles, coverage is under the G10 program, requiring owner verification. If the vehicle is outside of any warranty coverage, this TSB serves as informational guidance only. The service number for this procedure is 6953, with a damage code of 0039. Diagnostic time is allocated as 0150 0000 (Max 50 TU), and a post-service road test is allocated 0121 0004 (10 TU).

TSB Revision History

This bulletin, TSB 69 24 11 2056406/5, was last revised on June 26, 2024 (Revision 5) to add model year 2025 to the header. It supersedes Technical Service Bulletin Group 69 number 23-91 dated June 30, 2023. Previous revisions include Revision 4 (June 30, 2023) and Revision 3 (February 10, 2022).

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Source: NHTSA ID: 11002933