Circuit/System Description

The body control module (BCM) controls the ignition main relay through the control circuit by applying voltage to the ignition run/crank relay coil control circuit. The ignition main relay is energized when the ignition is in the ON, CRANK positions, or when a remote start is requested.

The keyless entry control module controls the backup power for the ignition main relay through the control circuit by applying voltage to the ignition circuit. This circuit is a pass-thru in the BCM and will energize the ignition circuit when the vehicle is in the ON, CRANK positions or when a remote start is requested.