Circuit/System Description

The body control module (BCM) monitors the ignition inputs ignition off/run/crank voltage, ignition 1 voltage and the accessory voltage signals supplied from the ignition switch. The ignition key resistor signal circuit provides 5-volt reference from the BCM to 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.