Restraints Control Module (RCM)
WARNING: This page is about a different car, the 2002 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.
RCM contains microcomputer, which monitors electrical system components and connections. RCM performs a system self-check of air bag system internal circuits every time ignition switch is turned to RUN position. RCM also energizes AIR BAG warning light during initial system self-check and whenever a fault is detected. Faults are stored in RCM memory and translated into flash codes, which are displayed through AIR BAG warning light. RCM also communicates through Data Link Connector (DLC) current and historical Diagnostic Trouble Codes (DTCs).
If a system fault exists and AIR BAG warning light is malfunctioning, RCM signals Generic Electronic Module (GEM) to activate a chime, indicating need for service.