Door LOCK Button
WARNING: This page is about a different car, the 2000 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
When transmitter LOCK button is pressed once, transmitter sends an identification code to remote control door lock receiver to lock both doors. The receiver sends a signal to both Door Control Modules (DCMs) on the serial data line to lock both doors. The DCM then locks both doors. The Body Control Module (BCM) arms Universal Theft Deterrent (UTD) system.