Headlamp Washer System
The headlamp washer pump is controlled by the body control module (BCM) via a printed circuit board (PCB) relay. If the headlamp lights are on, the BCM will activate the headlamp washer pump the first time the windshield washer pump is activated. After the initial headlamp washer activation, the BCM will only allow headlamp washer function every 5 windshield washer cycles. When the headlamp washer function is requested by the BCM's internal logic, it applies voltage through a control circuit to the headlamp washer pump relay. With the relay energized, battery voltage is applied through the switch contacts of the relay and the fused control circuit to activate the headlamp washer pump.