Circuit/System Description

WARNING: This page is about a different car, the 2015 Chevrolet Trax and 2015 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.

The body control module (BCM) controls the ignition main (underhood), ignition main (rear body), ignition run, blower motor and the retained accessory power relays by applying voltage to their individual relay control circuits. The ignition main relay (underhood) and ignition main relay (rear body) are energized when the ignition is in the ON or the CRANK position. The BCM controls the ignition main relay (underhood) and ignition main relay (rear body) through the control circuit by applying voltage to the ignition run/crank relay control circuit. The blower motor relay and the ignition run relay are energized when the ignition switch is in the ACCESSORY or ON positions. The BCM controls the blower motor relay and ignition run 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 BCM also controls the battery saver relay through individual circuits by applying voltage to the battery saver set and reset circuits. The battery saver relay is a latching relay that when enabled disconnect some modules from their ignition power or memory power sources.

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