Wash Operation

When the windshield Wash switch is pressed, battery voltage is applied through the switch contacts and the windshield washer switch signal circuit and the body control module (BCM) to the windshield washer pump. The BCM monitors the voltage on the windshield washer switch signal circuit to detect when a WASH cycle is requested so it can also enable the wipers. After a short delay, the BCM energizes the wiper ON/OFF relay which will operate the windshield wiper motor at low speed. The wiper motor will continue to operate for 2 wipe cycles after the wash switch is released.