Circuit/System Description

As the power mode master (PMM), the body control module (BCM) monitors the ignition inputs off/run/crank voltage, ignition 1 voltage and the accessory voltage signals supplied from the ignition switch. The BCM uses the sequence that the signals appear, their voltage levels, the engine run flag (ERF) status and the remote start status to determine the power mode.

When the vehicle operator places the ignition switch in the ACC or RUN position, the switch supplies B+ to the BCM accessory voltage input terminal. If this circuit becomes shorted to B+, ground or the circuit opens, DTC B1380 will set.