Side SIR System Description

WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

The side impact SIR system consists of the following components:

AIR BAG indicator in the instrument panel cluster (IPC)
Inflatable restraint sensing and diagnostic module (SDM)
Inflatable restraint side impact modules-LF
Inflatable restraint side impact modules-RF
Inflatable restraint side impact sensors (SIS)-LF
Inflatable restraint side impact sensors (SIS)-RF
Inflatable restraint seat belt pretensioner-LF, Buick
Inflatable restraint seat belt pretensioner-RF, Buick

The side impact modules are located in the outside portion for the front seat backs. The side impact modules consist of a housing, inflatable air bag, initiating device, and a canister of gas generating material. The initiator is part of the side impact module deployment loop. When a side impact of sufficient force occurs, the SIS detects the impact and sends a signal to the SDM. The SDM compares the signal received from the SIS to a value stored in memory. When the generated signal exceeds the stored value, the SDM will cause current to flow through the side deployment loop, deploying the inflator module. The SDM, side impact modules, and the connecting wires make up the side deployment loops. The SDM continuously monitors the side deployment loops for malfunctions and commands the IPC to turn the AIR BAG indicator ON if a fault is present. Each side impact module is equipped with a shorting bar located in the connector of the module. The shorting bar shorts the side impact module deployment loop circuitry to prevent unwanted deployment of the air bag when it is disconnected.