GM Service Manual Online
For 1990-2009 cars only

Restraint Devices


Object Number: 68681  Size: LH

The frontal Supplemental Inflatable Restraint (SIR) system supplements the protection offered by the driver and front passenger seat belts. 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 (1). The knee bolsters (3) absorb crash energy. The driver and passenger knee bolsters are below the instrument panel. The steering column is collapsible. After an AIR BAG deployment, the SDM will send out a post-air bag deployment message to the Rear Integration Module (RIM). The RIM will unlock the doors and turn ON the interior lights 15 seconds after receipt of this message.

Frontal Inflatable Restraint Devices


Object Number: 143167  Size: SH

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

Frontal SIR System Description

The frontal SIR system consists of the following components:

    • An inflatable restraint sensing and diagnostic module (SDM)
    • An inflatable restraint steering wheel module (steering wheel air bag)
    • An inflatable restraint steering wheel module coil
    • An inflatable restraint IP Module (IP air bag)
    • An AIR BAG Warning Lamp in the instrument panel cluster (IPC)

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, deploying the frontal inflator modules simultaneously. 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 generates 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 inflator modules.

Side Impact Inflatable Restraint Devices


Object Number: 235716  Size: MH

The side impact inflatable restraint system supplements the protection offered by the driver or passenger door (2), and the vehicle structure along with the protection offered by the driver and passenger seat belts. The side impact air bag system deploys an air bag (1) from the side of the driver or front passenger seat. A side crash of sufficient force will deploy a side air bag.

Side Impact Air Bag System Description

The side impact air bag system consists of the following components:

    • Two inflatable restraint side impact sensors (SIS) (one in each lower center pillar)
    • Two inflatable restraint side impact inflator modules (one side air bag in each front seat)
    • An inflatable restraint sensing and diagnostic module (SDM)
    • An AIR BAG Warning Lamp in the instrument panel cluster (IPC)

The inflatable restraint side impact sensor (SIS), inflatable restraint side impact inflator modules (Side Air Bags), inflatable restraint sensing and diagnostic module (SDM), and the connecting wires make up the side impact inflatable restraint system. The SDM contains a sensing device (accelerometer) that converts vehicle velocity changes to an electrical signal. The SIS is treated as a discriminating sensor and is a input to the SDM. If the SIS determines that the side air bags should be deployed, the SIS tells the SDM to deploy the side air bags. The SDM will then check to see if there is enough vehicle acceleration to warrant a deployment. If so, the SDM will send current to the side air bag deploying the side air bag module. Deployment occurs when the SDM receive vehicle velocity changes through the SIS that are severe enough to warrant deployment.