TrailBlazer 2WD L6-4.2L VIN S (2003)
Malfunction Lamp / Indicator: Description and Operation
AIR BAG INDICATOR
The AIR BAG indicator, located in the IPC is used to notify the driver of SIR system malfunctions and to verify that the SDM is communicating with
the IPC. When the ignition is turned ON, the SDM is supplied with ignition positive voltage. The SDM requests the IPC to flash the AIR BAG
indicator seven times. While flashing the indicator, the SDM conducts test on all SIR system components and circuits. If no malfunctions are detected
the SDM will communicate with the IPC through the class 2 serial data circuit and command the AIR BAG indicator OFF. The SDM provides
continuous monitoring of the air bag circuits by conducting a sequence of checks. If a malfunction is detected the SDM will store a Diagnostic Trouble
Code (DTC) and command the IPC to turn the AIR BAG indicator ON via class 2 serial data. The presence of a SIR system malfunction could result
in non-deployment of the air bags or deployment in conditions less severe than intended. The AIR BAG indicator will remain ON until the
malfunction has been repaired.
