Air Bag Control Module: Description and Operation

The inflator modules consist of an inflatable bag (1) and an inflator (4) (a canister of gas-generating material and an initiating device). These components are concealed behind a trim vinyl cover (2), positioned in the center of the steering wheel (3).

When the vehicle is in a frontal crash of sufficient force, the Inflatable Restraint SDM causes a current to flow through the deployment loops. Current passing through the initiator ignites the material in the inflator module. The gas produced from this reaction rapidly inflates the air bag.

A shorting bar is placed on the Inflatable Restraint Steering Wheel Module side of the upper steering column connector which connects the Inflatable Restraint Steering Wheel Module Coil to the Inflatable Restraint Steering Wheel Module. The shorting bar shorts across the Inflatable Restraint Steering Wheel Module circuits when the upper steering column connector disconnects. The circuit to the Inflatable Restraint Steering Wheel Module is shorted in this way in order to help prevent unwanted deployment of the air bag while you are servicing the Inflatable Restraint Steering Wheel Module, the steering column (3), or the other SIR system components.

A shorting bar is placed on the Inflatable Restraint Instrument Panel (IP) module connector which connects to the SIR wiring harness. This shorting bar shorts across the Inflatable Restraint IP module circuits when the Inflatable Restraint IP module connector disconnects. The circuit to the Inflatable Restraint IP module is shorted in this way in order to help prevent unwanted deployment of the air bag while you are servicing the Inflatable Restraint IP module, the instrument panel (2), or the other SIR system components.