Windshield Washer System

The windshield washer pump is controlled by the body control module (BCM) via a printed circuit board (PCB) relay. When the washer switch is depressed, the BCM monitors the Windshield Washer Switch signal circuit from the Windshield Wiper/Washer Switch. The BCM then applies voltage through a control circuit to the PCB windshield washer pump relay. With the relay energized, fused battery voltage is applied through the switch contacts of the relay and the control circuit to activate the windshield washer pump. To initiate wash operation, the Windshield Wiper/Washer switch should be pressed, causing the windshield washer to spray the washer fluid into the windshield, and the wiper automatically starts wiping.

Fig 1: Windshield Washer System Block Diagram

Courtesy of GENERAL MOTORS COMPANY