Door Modules
WARNING: This page is about a different car, the 2002 Oldsmobile Aurora and 2001 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
The drivers door module (DDM) communicates with the other door modules via the power door serial data circuit. The DDM sends a class 2 message to the RIM in order to perform the appropriate function.