The body control module plays a part in every sub-system on the vehicle, from engine starting through keyless entry, lighting and retained accessory power. These BCM systems are not described in detail in this section. Refer to the description and operation for more details on the following systems:

Wake-up signals are signals which turn on the BCM. Once active, the BCM begins monitoring and controlling the system functions listed above. With the ignition switch in the OFF position, the BCM ceases control of the system functions after a 10 minute period. This is the sleep mode. During the sleep mode the BCM monitors several circuits for changes in status. The BCM wakes up when a change is detected on any of the following inputs:

The BCM will operate properly with a system voltage of 9-16 volts.

Important: If the BCM is replaced, refer to Body Control Module (BCM) Programming/RPO Configuration to program the new BCM to the current ignition key. Remember the BCM can only be programmed once.

Do not replace the BCM unless directed to do so by the diagnostic procedures in this section. Most system faults are traceable to faulty wiring, connectors or system components other than the control module. Do not replace the BCM before performing a complete diagnosis. This may result in the replacement of a good BCM and a recurrence of the fault.