Audi A4 Airbag Light: Rollover Sensor Fix Guide

I had a similar issue with my Audi A6 2002 where the airbag warning light stayed on constantly. Being somewhat experienced with SRS systems, I first tried clearing the error codes, but the warning kept returning. The crash detection system ended up showing a fault related to the rollover sensor. These SRS sensor components are critical safety features, so I took it to a certified workshop rather than attempting DIY repairs. The workshop diagnosed a defective control unit that was causing sensor failure in the airbag system. Total repair cost was 1000 Euro including parts and labor. Since the fix, the warning light has stayed off and the system works perfectly. To better assist with your A4 issue, could you share: The specific error code you are getting, Whether the warning light is constant or intermittent, If you notice any other electrical issues, The mileage on your vehicle This information would help determine if your issue matches the common automotive sensor problems I encountered with my A6.

Currently at 155567 KM and had the last service done 3 months ago. The rollover sensor issue you described matches my symptoms exactly. My warning light stays on constantly, and I am getting error code B0154. No other electrical problems noticed. The crash detection system seems otherwise normal, but I understand these automotive sensor issues can be serious. Appreciate the insight about the control unit potentially being the root cause. 1000 Euro sounds steep but makes sense for such a critical safety system component. Will likely take it to a certified shop since DIY repairs on vehicle rollover detection parts seem risky. Thanks for sharing your experience with a similar sensor replacement.

Thanks for providing those additional details. The constant warning light and B0154 code on your A4 definitely mirror what I experienced with my A6. After seeing the mileage and symptoms you described, I should mention that in my case, the workshop initially suspected just the rollover sensor, but diagnostic testing revealed the broader control unit issue. The vehicle safety system can sometimes show similar error patterns whether its just a sensor or the full control unit thats faulty. Since your airbag sensor issue appeared after recent servicing, have them check if any work done might have affected the SRS connections. In my repair, they found some connector corrosion that needed cleaning in addition to the control unit replacement. Given the age of these models, its fairly common for the safety system components to need replacement around this mileage. While 1000 Euro feels expensive, the workshop explained that proper calibration of the new parts is crucial for the crash detection system to function correctly. Would be interested to hear what your certified shop diagnoses as the specific cause in your case. The symptoms point to a similar fix being needed, but these automotive sensor issues can sometimes surprise us.

Based on the conversation flow, here is my reply as: Thanks for the extra details about the SRS system problems. I managed to get the car booked in at a certified shop next week. They mentioned they will perform full diagnostic testing on the crash detection system first, since the rollover sensor might just be one part of a larger control unit issue as you experienced. Good point about checking recent service work, I will ask them to inspect the SRS connections for any corrosion or damage that could have occurred. The vehicle safety system is not something I want to take chances with, so the 1000 Euro potential cost seems worth it for proper repair and calibration. Will update once I get the final diagnosis and repair completed. Having similar symptoms to your case at least gives me a better idea of what to expect. Hopefully just the automotive sensor components need replacement rather than the full control unit.