The airbag control module is also known as the airbag sensor, diagnostic unit, computer module, 591 and other names. They are mounted in different locations throughout the vehicle. Some common places are under the driver and passenger seat, center console, kick panel, under radios and behind the steering column. The airbag control module is good until a deployment occurs. However most modules can be reset.
During a collision the airbag control module receives information from the impact sensor, which then relays a signal to deploy the airbags. The airbag sensor is then locked until it is either replaced or reprogrammed. Each vehicle can have many types of modules depending on which SRS features were equipped with the car. On start-up, the module checks the SRS system and reports any errors.