Circuit Description
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
When ignition switch is turned on, SDM performs tests to diagnose critical internal malfunctions. Sensing and Diagnostic Module (SDM) monitors passenger-side air bag high-side and low-side circuit voltage differences. SDM uses voltage difference to calculate circuit resistance. A low deployment loop resistance indicates passenger-side air bag module circuits are shorted together.