Circuit/System Description

WARNING: This page is about a different car, the 2016 Chevrolet Trax and 2016 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.

The body control module (BCM) controls the windshield washer based on an input from the windshield washer switch, which is part of the windshield wiper/washer switch. The BCM monitors the windshield washer switch through a discrete signal circuit. When the washer switch is pressed, the signal circuit is pulled to ground. The BCM will respond by commanding the washer function.

The windshield washer uses a single windshield washer pump to provide fluid for both the front and rear washers. Changing the polarity of the motor will cause it to spin in opposite directions, feeding fluid to the front or rear. When front washers are requested, the BCM applies voltage to the windshield washer pump relay control circuit. This causes the contacts in the windshield washer pump relay to close and supplies voltage to the windshield washer pump. Ground for the windshield washer pump is provided through the rear window washer pump relay, which is switched to ground in it's at-rest state.