Description & Operation
WARNING:
Deactivate air bag system before performing any service operation. See AIR BAG RESTRAINT SYSTEM article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.
NOTE:
Body Control Module (BCM) may also be referred to as Multifunction Alarm, Lock & Lighting (MALL) module.
The Multifunction Alarm, Lock and Lighting (MALL) controls different body systems by obtaining information from various sensors and switches, then using this information to command the output to each body system. MALL module provides a set of internal service diagnostic features to assist technician in troubleshooting electrical short conditions that may affect MALL. If electrical short occurs during vehicle operation, MALL module stores history codes. These codes can be accessed by entering MALL module diagnostic mode. After providing history codes, MALL module enters Input/Output (I/O) mode. I/O mode enables verification that inputs to MALL module are functioning properly.