Circuit/System Description

WARNING: This page is about a different car, the 2015 Chevrolet Trax and 2015 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.

When the ignition is turned ON, during the bulb check, the driver air bag indicator will flash, and then turn OFF after the bulb check. The inflatable restraint sensing and diagnostic module (SDM) performs diagnostic tests on the SIR system during the bulb check. If any malfunction exists the SDM will request the instrument cluster to illuminate the air bag indicator steady, via serial data. If a preexisting malfunction exists, the air bag indicator will illuminate steady immediately after the ignition is turned ON. If the ignition 1 voltage is outside of the normal operating voltage range of 9-16 V, the inflatable restraint sensing and diagnostic module will command the instrument cluster to illuminate the air bag indicator ON, even with no DTCs present, and then disable all deployment loops.