Circuit/System Description
WARNING: This page is about a different car, the 2007 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) stores the last 4 digits of the sensing and diagnostic module (SDM) part number, information also called restraints ID. After the BCM is reprogrammed, the restraint ID is set to zero, and a restraint ID relearn needs to be performed.