Air Bag

The inflatable restraint Sensing and Diagnostic Module (SDM) controls the air bag indicator over the class 2 serial data line. The SDM will turn the indicator ON for approximately 3 seconds during the engine start up in order to perform a bulb check. The SDM will turn the indicator ON in order to warn the driver of a Supplemental Inflatable Restraint (SIR) electrical system malfunction, possibly affecting the operation of the SIR system. Refer to SIR System Operation in SIR.