Air Bag Control Module: Description and Operation

The electronic air bag control module governs the operation of the whole system, including the diagnostic element. It contains two frontal impact sensors; a crash sensor and a safing sensor. The crash sensor produces a signal corresponding to the rate of deceleration. The safing sensor detects only deceleration. These two sensors are connected in series and if they both sense a deceleration in excess of a predetermined limit, the electronic air bag control module will deploy the air bag module(s).

The electronic air bag control module will also deploy the corresponding side air bag module dependent on the signal received from either crash sensor.

The electronic air bag control module also performs continual system diagnostics. In the event of a fault being detected the warning light is illuminated either constantly or intermittently. The behavior of the warning light depends on the type of fault present. The warning light is located in the instrument cluster.

The wiring harness provides power to the electronic air bag control module from the vehicle supply and hence to the air bag module(s), side impact crash sensors (if equipped with side air bags) and the warning indicator.