Circuit/System Description

The body control module (BCM) controls the ignition main, ignition run/crank, steering wheel heater and the retained accessory power relays by applying voltage to their individual relay control circuits. The ignition main relay and ignition run/crank relays are energized when the ignition is in the ON or the CRANK position. The BCM controls the ignition main relay and ignition run/crank relay through the control circuit by applying voltage to the run/crank relay control circuit. The steering wheel heater relay is energized when the ignition switch is in the ACCESSORY or ON positions. The BCM controls the steering wheel heater relay through the control circuit by applying voltage to the auxiliary ignition run relay control circuit. The retained accessory power relay is energized during all power modes, except OFF-awake and CRANK. The retained accessory power relay is also energized for approximately 10 min after shutting the ignition OFF, providing no door is opened. The BCM controls the retained accessory power relay through the control circuit by applying voltage to the accessory/retained accessory power relay control circuit.

The engine control module (ECM) controls the powertrain relay by applying voltage to the powertrain relay control circuit.