Circuit/System Description

The washer fluid pump is a reversible motor and is used to wash both the windshield and rear window.

When the windshield wash switch is pressed, ground is applied through the switch contacts and the windshield washer switch signal circuit to the body control module (BCM) indicating the windshield wash request. The BCM then energizes the windshield wash relay by grounding the relay control circuit to the coil side of the relay. With the windshield wash relay energized, battery voltage is supplied to the windshield wash control circuit of the washer fluid pump and grounded through the de-energized rear wash relay.

When the rear window wash switch is pressed, ignition voltage is applied through the switch contacts an the rear window wiper/washer switch signal circuit to the rear window wiper motor module. The rear window wiper motor module energizes the rear window wash relay by applying battery voltage to the relay control circuit. With the rear window wash relay energized, battery voltage is supplied to the rear window wash control circuit of the washer fluid pump and grounded through the de-energized windshield wash relay.