Circuit Description
WARNING: This page is about a different car, the 2003 GMC Sonoma, 2003 GMC Jimmy, 2003 Chevrolet S10 Pickup, and 2003 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.
After enter RUN mode, the inflatable restraint sensing and diagnostic module (SDM) receives the VIN from BCM, via class 2 serial data circuit. SDM receives also a message from BCM containing its restraints ID. The restraints ID contains the last four digits of the SDM part number. The module compares the information stored in its memory with the information received from the BCM.