Circuit Description

When ignition is turned to RUN position, Instrument Panel Cluster (IPC) flashes AIR BAG indicator seven times. Inflatable restraint Sensing And Diagnostic Module (SDM) performs diagnostic tests on Supplemental Inflatable Restraint (SIR) system and then commands IPC to turn AIR BAG indicator OFF, if no SIR malfunction exists. AIR BAG indicator is controlled by SDM via class 2 serial data. If ignition 1 voltage is outside of normal operating voltage range 9-16 volts, SDM will command IPC to turn AIR BAG indicator On with no DTCs present.