The headlamp washer system consists of the following components:

Body control module

The body control module controls the headlamp washer pump using a programmed pulse type wash sequence. The washing sequence is a short wash pulse followed by a delay time to let the water soak which is then followed by another wash cycle for a programmed amount of time. The headlamp washer pump is controlled by the body control module through the headlamp washer relay. The headlamp washer switch signal circuit is supplied a 12-volt reference through a resistor then monitored within the body control module. The headlamp washer switch is open when in an inactive state. When the headlamp washer switch is activated the signal circuit is closed to ground. When the headlamp washer switch signal circuit is closed to ground the reference voltage is dropped across the resistor within the body control module. The low voltage on the headlamp washer switch signal circuit indicates to the body control module the switch status is active. Battery positive voltage is supplied to the coil and switch sides of the headlamp washer relay. When a headlamp wash request is active the body control module energizes the headlamp washer relay by grounding the relay coil through the headlamp washer relay control circuit. When the relay is energized battery positive voltage to the relay switch is supplied to the washer pump control circuit. The headlamp washers activate for one wash-wait-rinse cycle when the front windshield washer button is pressed for the first time after the vehicle is turned on. The headlamps washers then activate automatically for one cycle after every four front windshield washes. The headlamps must be on to be washed. If the headlamps are off, only the front windshield will be washed. The headlamp washers use the same fluid bottle as the windshield washer. However, the headlamp washers will run out of fluid before the windshield washer. If the windshield can be washed, but not the headlamps, check the fluid level.