Wiper and Washer Systems: Description and Operation

Wiper/Washer System Description and Operation

Wiper/Washer System Components

The windshield wiper/washer system consists of the following components:

* Body control module (BCM)
* Windshield washer pump
* Windshield washer solvent container
* Windshield wiper arm and blade assembly
* Windshield wiper motor
* Windshield wiper/washer switch
* WSW PUMP fuse 15 A
* REAR WPR fuse 20 15 A
* REAR WPR Relay 17
* REAR WSW Relay 48

Windshield Wiper/Washer System Description and Operation

Battery positive voltage is supplied through the REAR WPR fuse to the coil and switched sides of the REAR WPR relay. When the BCM receives a signal from the Rear Wiper/Washer switch, the BCM provides ground to the coil side of the relay and providing a path for voltage to the Rear Window Wiper motor, activating the motor. The Rear Window Wiper motor receives a path to ground from G402. Except for when it is in the Wash mode, the rear window wiper wipes the rear window at delay time intervals.

Wash Operation

During the Wash mode, if the rear washer switch is momentarily turned to ON, the rear wiper will wipe the rear window 3-5 times and then park. However, if the rear washer switch is held to ON, the rear window wipers will continue to operate until the switch is released. The REAR WSW relay 48 receives voltage on the coil and switched sides from the WSW PUMP fuse. When the rear washer is activated, the BCM supplies ground to the switched side of the REAR WSW relay 48, activating the relay. The relay then supplies voltage to the Windshield Washer Fluid pump. The Windshield Washer Fluid pump receives a path to ground through the WSW PUMP relay. The Windshield Washer Fluid pump is bidirectional and provides washer fluid for both the front and rear windshields. The direction of the Windshield Washer Fluid pump is determined by the state of the REAR WSW relay and the WSW PUMP relay.

The windshield washer pump sprays solvent onto the windshield. The windshield wipers operate at low speed for 3-5 wipes and returns to the park position.

Park Position Operation

The BCM supplies voltage to signal circuit of the rear windshield wiper motor park switch. The BCM monitors this signal to determine if the Rear Window Wiper motor is still operating or it has parked. The signal will be pulled to ground by the rear windshield wiper motor park switch while the windshield wiper motor is operating. When the windshield wiper motor has parked, the signal is at normal voltage because of the rear windshield wiper motor park switch being open.