Airbag control unit

Airbag control modules don’t have any common faults, but like any module/control unit they can experience electrical issues and corrosion.

It’s worth noting that airbag control modules will show a fault after the airbags and restraints are deployed in a collision—as far as we understand it means that the module will need to reset by a BMW dealer or someone with dealership grade equipment.

The airbag control module plays a central and critical role in BMW’s earlier Multiple Restraint System (MRS), as well as their later Active Crash Safety (ACS) systems.

Ultimately the role of this module is to process data from various sensors in the car, and if it predicts/senses a crash—to then deploy the airbags and restraint systems.

The more advanced ACS systems are much more predictive—and are usually integrated with the brake system.

Second-hand airbag modules are already coded and can have different firmware versions installed.

Therefore, the best way of determining whether an airbag control module is compatible with your vehicle is to match the part numbers physically on both units. This will mean that the firmware version is the same as the unit in your vehicle, making it easy to code the module.

The location of the airbag control module varies between model—but in most BMWs it is located under the centre console or above the transmission tunnel.

Whilst there is interchangeability between models, it is worth finding a module from the same model if you can—it will ensure coding is more straight forward.