What the airbag control module does on your Audi
Audi uses the same airbag computer as Volkswagen, the airbag control module, sometimes called the ACU. On an A4, a Q5 or an A6, it runs the supplemental restraint system. It reads the impact sensors, fires the airbags and pretensioners in a crash, and records the deployment along with the supply-voltage and fault data that keeps the warning light on.
Once that data is stored, the module locks and the airbag light stays on. A scanner cannot clear it, and Audi modules are coded to the car, which is why a dealer replacement has to be coded to your VIN before it will work. We reset your original Audi airbag control module in our shop, erase the crash data and hard codes, and return it factory-ready with its coding intact. It plugs straight back in and works the moment you reinstall it.
