Side Impact Air Bag System Description

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 side of the driver or front passenger seat. A side crash of sufficient force will deploy a side air bag.

The side impact air bag system consists of the following components:
1. Two Inflatable Restraint Side Impact Sensors (SIS) (One in each B-pillar)
2. An Inflatable Restraint Front Side Impact Module in the driver's seat
3. An Inflatable Restraint Front Side Impact Module in the front passenger's seat
4. An AIR BAG Warning Lamp in the Instrument Panel Cluster
5. An Inflatable Restraint Sensing and Diagnostic Module (SDM)

The inflatable restraint side impact sensor (SIS), the inflatable restraint front side impact 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 SISs detects a side impact severe enough to warrant deployment.

The SIS contains a sensing device (accelerometer) that converts acceleration into an electrical (analog) signal. This signal is converted by a microprocessor in the SIS 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 SIS will send deployment data to the SDM. The SDM will then compare the received data to the data that is stored within the SDM. If the received data matches the stored data, the SDM will cause current to flow through either the driver or passenger inflatable restraint front side impact module, causing the inflator module to deploy.