The frontal Supplemental Inflatable Restraint (SIR) system supplements the protection offered by the driver and front passenger seat belts (2). The frontal SIR system deploys an air bag (1) from the center of the steering wheel and from the right side of the instrument panel. The knee bolsters (3) absorb crash energy. The driver and passenger knee bolsters are below the instrument panel. The steering column is collapsible.

A frontal crash of sufficient force up to 30 degrees off the longitudinal centerline of the vehicle will deploy the frontal air bags.

The frontal SIR system consists of the following components:

1. Inflatable Restraint Sensing and Diagnostic Module (SDM)
2. Inflatable Restraint Steering Wheel Module
3. Inflatable Restraint Steering Wheel Module Coil
4. Inflatable Restraint IP Module
5. AIR BAG Warning Lamp, located within the Instrument Panel

The inflatable restraint sensing and diagnostic module (SDM), inflatable restraint steering wheel module coil, inflatable restraint steering wheel module, inflatable restraint IP module, and the connecting wires make up the frontal deployment loops. The function of the frontal deployment loops is to supply current through the frontal inflator modules, which will cause deployment of the frontal air bags. Deployment occurs when the SDM detects vehicle velocity changes severe enough to warrant deployment.

The SDM contains a sensing device (accelerometer) that converts vehicle velocity changes to an electrical signal. The SDM compares this electrical signal to a value stored in memory. When the generated signal exceeds the stored value, the SDM performs additional signal processing and compares the generated signals to values stored in memory. When two of the generated signals exceed the stored values, the SDM will cause current to flow through the frontal inflator modules, deploying the frontal air bags.

The side impact air bag system supplements the protection offered by the driver door and the vehicle structure. The side impact air bag system deploys the driver side air bag from the side of the driver seat. A side crash of sufficient force will deploy the driver side air bag.

The side impact air bag system consists of the following additional components that interface with the inflatable restraint sensing and diagnostic module (SDM):

1. Inflatable Restraint Side Impact Sensor (SIS), located in the lower LH B pillar
2. Inflatable Restraint Side Impact Module, located in driver's seat back

The inflatable restraint side impact sensor (SIS), the inflatable restraint side impact module, and the connecting wires make up the side impact deployment loop. The function of the side deployment loop is to supply current through the side impact module, which will cause deployment of the driver side air bag. Deployment occurs when the SIS 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 signals the SDM to cause current to flow through the side impact module, deploying the driver side air bag.