Circuit/System Description
WARNING: This page is about a different car, the 2017 Chevrolet Spark. However, it is still accessible from the selected car via links, so may be relevant.
When the ignition switch is turned to ON, the inflatable restraint sensing and diagnostic module (SDM) will perform turn-on test to diagnose critical malfunctions within SDM itself. The SDM continuously checks the passenger air bag disable switch position and circuit defect by letting the regular voltage flow through the passenger air bag disable switch circuit and verifying the current.