Circuit Operation

The Supplemental Restraint System (SRS) consists of the Sensing and Diagnostic Module (SDM), the driver's inflator module, the SRS coil assembly, the passenger's inflator module, and the AIR BAG readiness indicator light in the meter assembly. The SDM, SRS coil assembly (driver side only), driver's inflator module, passenger 5 inflator module, and connector wire make up the deployment loops. The function of the deployment loops is to supply current through the inflator modules, which will cause deployment of the air bags in the event of a frontal crash of sufficient force, up to 30 degrees of the centerline of the vehicle. The inflator modules are only supplied enough current to deploy when the SDM detects vehicle velocity changes that are severe enough to warrant deployment.

The SDM contains a sensing device which converts vehicle velocity change to an electrical signal. The electrical signal generated is processed by the SDM and then compared to a value stored in memory. When the generated signal exceeds the stored value, the SDM will cause current to flow through the inflator modules deploying the air bags.