2021-2024 Audi Q5 Airbag Warning Light DTCs B100A1B, B100B1B

If you own a 2021-2024 Audi Q5, Q5 e quattro, or SQ5 and have noticed the "airbag warning light on" in your instrument cluster, Audi has issued a Technical Service Bulletin (TSB) 2072349/2 to address this concern. This bulletin, which supersedes TSB Group 69 number 23-05 dated December 13, 2023, provides a detailed explanation and repair procedure for the underlying cause of the warning light.

The TSB specifically targets situations where diagnostic trouble codes (DTCs) B100A1B or B100B1B are stored in the airbag control module. These codes indicate a resistance issue with the airbag igniters, which can compromise the proper function of the airbag system. This article will explain the symptoms, causes, and the recommended repair for the Audi Q5 airbag warning light.

Symptoms

The primary symptom owners will notice is the "airbag warning light on" illuminating on the vehicle's dashboard. This light indicates a detected fault within the airbag system, which requires immediate attention to ensure the safety system is fully operational.

Fault Codes / DTCs

When the airbag warning light is on, a scan of the airbag control module (-J234-, address word 0015) will typically reveal one or both of the following diagnostic trouble codes:

Code	Description	Module
B100B1B	Driver thorax airbag igniter Resistance too high	J234
B100A1B	Front passenger side airbag igniter Resistance too high	J234

These codes directly point to an issue with the electrical resistance in the igniter circuits for the side/thorax airbags.

Technical Background

Audi has identified that the root cause of the increased resistance is the wire harness for the side/thorax airbag being positioned too close to the seat foam. Over time, the seat foam can exert pressure on this wire harness, leading to movement of the airbag connector. This movement can cause an increase in electrical resistance within the circuit, triggering the airbag warning light and storing the associated DTCs. Audi implemented an optimization in series production for Model Year 2024 vehicles to prevent this issue.

Repair Procedure Summary

The repair outlined in TSB 2072349/2 involves replacing the affected side/thorax airbag wire harness(es) and ensuring proper routing to prevent future issues.

1. Harness Replacement: Technicians must replace the faulty side/thorax airbag wire harness(es). This procedure should follow the detailed instructions found in the Elsa repair manual under "Body >> Body Interior >> Passenger Protection, Airbags, Seat Belts >> Thorax Airbags >> Thorax Airbag Wire, Removing and Installing."
2. Proper Routing: After replacement, the new wire harness(es) must be routed as close to the seat frame as possible. This is achieved using a specific zip tie/clip, part number N10546701. (Figures in the TSB illustrate the correct routing and clip usage, though the TSB notes that the clip shown in the photo may not be identical to the one to be used).
3. DTC Deletion: Once the new harness is installed and correctly routed, all stored DTCs in the airbag control module (J234) must be deleted.
4. Final Verification: A final check of the airbag control module's fault memory is required to confirm that the DTCs B100A1B and B100B1B have not returned, ensuring the repair is successful and the Audi Q5 airbag warning light is off.

Required Parts and Tools

To perform this repair, specific parts and tools are necessary:

• Side Airbag Harness: Part Number 80A 971 553 (Quantity: 01 or 02, depending on which side(s) are affected).
• Tie Wrap/Clip: Part Number N10546701 (Quantity: 01 or 02, considered a shop supply).
• Fasteners: Various fasteners, bolts, nuts, and screws as needed per the repair manual (See ETKA/ELSA).
• Diagnostic Tool: VAS 6160/VAS 6150 tester with the current version of ODIS (Windows 10) for diagnosis and DTC management.

Warranty Information

This repair is generally covered under Audi's New Vehicle Limited Warranty for up to 48 months or 50,000 miles, whichever comes first (Claim Type 110). For Audi Certified Pre-Owned (CPO) vehicles, coverage may apply under Claim Type G10, subject to owner verification.

Important Warning: If your vehicle is outside of any applicable warranty, this Technical Service Bulletin is informational only, meaning the repair costs would likely be the owner's responsibility. Owners should consult with their Audi dealership for specific warranty applicability.

The service number for this procedure is 9766, with a damage code of 0015. Labor operations include "Side airbag wire harness, remove+reinstall" (9766 1999 for one harness, 9766 2099 for two harnesses), and diagnostic time (GFF 0150 0060). Additional time is allocated for battery charge (2706 8950). All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual.

What Owners Should Do

If your 2021-2024 Audi Q5, Q5 e quattro, or SQ5 is displaying the "airbag warning light on" or you suspect an issue with the airbag system, it is recommended to contact an authorized Audi dealership. Provide them with your vehicle's symptoms and mention Technical Service Bulletin 2072349/2. The dealership can diagnose the issue, confirm the presence of DTCs B100A1B or B100B1B, and perform the necessary repair to ensure the safety of your vehicle.

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Source: NHTSA ID: 11002141