Circuit Description
WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
When ignition is turned on, Sensing and Diagnostic Module (SDM) compares the restraints identification that is stored in SDM to restraints identification that is stored in Body Control Module (BCM). Next, SDM compares Vehicle Identification Number (VIN) stored in SDM to VIN stored in Electronic Control Module (ECM)/Powertrain Control Module (PCM).