GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 146
SUPPLEMENTAL INFLATABLE RESTRAINT SYSTEM
GENERAL INFORMATION
All 1990-1992 models are equi
pped with an airbag system. The Supplemental
Inflatable Restraint (SIR) syst em helps supplement the protection offered by the
seat belts by deploying an ai r bag from the center of the steering wheel. The air
bag deploys when the vehicle is involved in a frontal crash of sufficient force up
to 30 degrees off the center line of the vehicle. To further absorb the crash
energy, there is a knee bolster located beneath the instrument panel and the
steering column is collapsible.
Fig. 1: SIR system deployment window
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 147
SYSTEM OPERATION
The main portions of the SIR system
are the deployment loops and the
Diagnostic Energy Reserve Module (D ERM). The main function of the
deployment loops is to supply current through the inflator module(s), which will
cause deployment of the air bag(s) in t he event of a frontal crash of sufficient
force. The arming sensor, SIR coil assembly (driver side only), passen\
ger
inflator module jumper (passenger side only), inflator module(s), passenger
compartment discriminating sensor and fo rward discriminating sensor make up
the deployment loops.
The DERM has two functions. One to supply the deployment loops with a 36
volt reserve to ensure sufficient energy is available to deploy the airbag(s) if the
battery voltage feed to the arming sensor is lost during a frontal crash. Another
function is SIR electrical system diagnostics.
The arming sensor switches power to th e inflator module(s) on the high side
(power side) of the deployment loops. Ei ther of the discriminating sensors can
supply ground to the inflator module(s) on the low side (ground side) of the loop.
The inflator module(s) ar e only supplied sufficient cu rrent to deploy when the
arming sensor and at least one of the two discriminating sensors are closed
simultaneously.
SYSTEM COMPONENTS
DIAGNOSTIC ENERGY RESERVE MODULE
The DERM is designed to perform the following functions in the SIR system:
• Energy Reserve - Maintains 36 volt energy reserve(s) to provide
deployment energy when the vehicle volt age is low or lost in a frontal
impact
• Malfunction Detection - Performs diagnostic monitoring of the SIR
system electrical components
• Malfunction Recording - Provides diagnostic trouble code information
• Frontal Crash Recording - Record s the SIR system status during a
frontal crash
WARNING LAMP
The "INFL REST" or "AIR BAG" warning lamp is used to do the following:
• Verify lamp and DERM oper ation by flashing seven to nine times when
the ignition key is first turned ON
• Warn the driver of SIR electrical system faults which could potentially
affect the operation of the SIR system
• Provide diagnostic information by fl ashing the fault codes when the
diagnostic mode is enabled
