General System Description

Description:

Wiring Diagram:

CAUTION: This vehicle has a Supplemental Inflatable Restraint (SIR) System. Refer to the SIR Component and Wiring Location view in order to determine whether you are performing service on or near the SIR components or the SIR wiring. When you are performing service on or near the SIR components or the SIR wiring, refer to the SIR Service information. Failure to follow the CAUTIONS could cause air bag deployment, personal injury, or unnecessary SIR system repairs.

NOTICE: Always use the correct fastener in the proper location. When you replace a fastener, use ONLY the exact part number for that application. General Motors will call out those fasteners that require a replacement after removal. General Motors will also call out the fasteners that require thread lockers or thread sealant. UNLESS OTHERWISE SPECIFIED, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems.

RESTRAINT DEVICES

The Supplemental Inflatable Restraint (SIR) system supplements the protection offered by the driver and front passenger seat belts. The SIR system deploys an air bag from the center of the steering wheel and from the right side of the instrument panel.
A frontal crash of sufficient force up to 30 degrees off the centerline of the vehicle will deploy the air bags. The knee bolsters and the steering column absorb crash energy. The driver and passenger Knee bolsters are below the instrument panel.

SYSTEM DESCRIPTION

The SIR system consists of the following components:

^ An Inflatable Restraint Sensing and Diagnostic Module.

^ An Inflatable Restraint Steering Wheel Module.

^ An Inflatable Restraint Steering Wheel Module Coil.

^ An Inflatable Restraint I/P Module.

^ An AIR BAG warning lamp in the instrument cluster.

The inflatable restraint Sensing and Diagnostic Module (SDM), inflatable restraint steering wheel module coil (SIR coil assembly), inflatable restraint steering wheel module (driver inflator module), inflatable restraint I/P module (passenger inflator module) and connector wires 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. Deployment occurs when the inflatable restraint sensing and diagnostic module detects vehicle velocity changes severe enough to warrant deployment.

The inflatable restraint sensing and diagnostic module contains a sensing device (Accelerometer) that converts vehicle velocity changes to an electrical signal. The inflatable restraint sensing and diagnostic module compares this electrical signal to a value stored in memory. When the generated signal exceeds the stored value, the inflatable restraint sensing and diagnostic module 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 inflatable restraint sensing and diagnostic module will cause current to flow through the inflator modules, deploying the air bags.