Side Impact Restraint Devices

The side impact air bag system supplements the protection offered by the driver door, the front passenger door, and the vehicle structure. The side impact air bag system deploys an air bag from the driver or front passenger door panel (Figure 1).

A side crash of sufficient force will deploy a side air bag.

SIDE IMPACT AIR BAG SYSTEM DESCRIPTION (DEVILLE MODELS ONLY)

The side impact air bag system consists of the following components:
^ Two Inflatable Restraint Side Impact Sensing Modules (SISM) (One in each front door)
^ Two Inflatable Restraint Side Impact Inflator Modules (One in each front door)
^ An AIR BAG Warning Lamp in the Instrument Panel Cluster (IPC)
^ An Inflatable Restraint Sensing and Diagnostic Module (SDM).

The inflatable restraint Side Impact Sensing Modules (SISM), the inflatable restraint side impact inflator modules, and the connecting wires make up the side impact deployment loops. The function of the side impact deployment loop is to supply current through the side impact inflator module, which will cause deployment of the side impact air bag. Deployment occurs when one of the SISM detects a side impact severe enough to warrant deployment.

The SISM contains a sensing device (Accelerometer) that converts acceleration into an electrical (analog) signal. This signal is convened by a microprocessor in the SISM into acceleration and velocity data. This data is used by a sensing algorithm and compared to various predetermined boundary conditions. when the acceleration value exceeds the predetermined threshold, and the velocity boundary is crossed, the SISM will cause current to flow through the inflatable restraint side impact inflator module.