Description & Operation

WARNING: Accidental air bag deployment is possible. Personal injury may result. Read and follow all WARNINGS and AIR BAG SAFETY PRECAUTIONS before working on air bag system or related components.

The Supplemental Restraint System (SRS), also known as air bag system, is designed to provide increased accident protection for driver and front passenger by deploying front air bags in a front-end collision. The air bag system is designed to work in conjunction with the 3-point seat belt system

The main components of the Air Bag System are the driver-side air bag module, contact coil (clockspring or SIR coil), passenger-side air bag module, Sensing and Diagnostic Module (SDM), left and right forward sensors and AIR BAG warning light. The driver-side air bag module, passenger-side air bag module and seat belt pretensioners are deployed by current supplied from SDM through squib circuits. The current ignites an ignition compound which causes the generation of a large quantity of nitrogen gas to rapidly inflate the air bags or activate pretensioner piston.

The contact coil is combined with the combination switch assembly and is mounted on the steering column. It allows rotation of the steering wheel while maintaining continuous contact of the driver-side deployment loop to the driver-side air bag module. The forward sensors and Sensing and Diagnostic Module (SDM) functions to detect velocity changes as a result of frontal collision severe enough to warrant air bag deployment. The SDM also performs malfunction monitoring of the air bag system, providing malfunction diagnosis through use of a Tech 1 scan tool.