K 3500 Truck 4WD V8-5.7L VIN R (1998)
Air Bag: Description and Operation
The inflator modules consist of an inflatable bag and an inflator. An inflator consists of a canister of gas-generating material and an initiating device. The
initiator is part of the deployment loop. When the vehicle is in a frontal crash of sufficient force, the inflatable restraint Sensing and Diagnostic Module
(SDM) causes current to flow through the deployment loops. Current passing through the initiator ignites the material in the inflator module. The gas
produced from this reaction rapidly inflates the air bag.
There is a shorting bar on the inflatable restraint steering wheel module side of the upper steering column connector that connects the inflatable restraint
steering wheel module coil to the inflatable restraint steering wheel module. The shorting bar shorts across the inflatable restraint steering wheel module
circuits during the disconnection of the upper steering column connector. The shorting of the inflatable restraint steering wheel module circuitry will help
prevent unwanted deployment of the air bag when servicing the inflatable restraint steering wheel module, the steering column or other SIR system
components.
There is a shorting bar on the inflatable restraint IP module connector that connects to the SIR wiring harness. The shorting bar shorts across the
inflatable restraint IP module circuits during the disconnection of the inflatable restraint IP module connector. The shorting of the inflatable restraint IP
module circuitry will help prevent unwanted deployment of the air bag when servicing the inflatable restraint IP module, the instrument panel or other
SIR system components. In the event of a fault in the inflatable restraint IP module switch circuitry, the SDM will detect the fault and set Diagnostic
Trouble Code (DTC) B1054, the SDM will attempt to illuminate the AIR-BAG OFF lamp, the AIR BAG warning lamp will turn ON and the inflatable
restraint IP module will default to the suppressed (disabled) state.
