Wiper/Washer System Description and Operation Front

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

With the ignition in the ON position, accessory voltage is supplied through the WIPER SW 10 A fuse in the fuse block that is part of the BCM to the wiper/washer switch.

G101 provides ground for the following:

The windshield wiper/washer switch supplies voltage on the signal circuit or the control circuit of the windshield washer pump to the BCM for windshield wiper/washer operation. When WASH, MIST, DELAY, LOW, or HIGH is detected, the BCM energizes the WPR Relay  70 by suppling voltage to the relay coil. This allows battery voltage from the WIPER fuse to flow through the relay switched input then through the contacts and out the relay switched output to the WPR Relay  52 switch contacts. Since the WPR Relay  52 switch contacts are normally closed to the low speed circuit of the windshield wiper motor, the motor will operate at low speed.

In the WASH position windshield wiper/washer switch supplies voltage on the signal circuit of the windshield washer pump to the BCM. The BCM then supplies voltage on the control circuit to the WASHER PUMP Relay  39 and the relay controls the windshield washer pump operation. The BCM monitors this voltage input to detect when a WASH cycle is requested so it can enable the wipers. The BCM energizes the WPR Relay  70 which will operate the windshield wiper motor at low speed.

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.

In the MIST position, voltage is supplied through a internal 562 Ω resistor to the signal circuit of the windshield wiper/washer switch for the BCM. The BCM will momentarily energizes the WPR Relay  70 which will operate the windshield wiper motor at low speed.

The windshield wipers make one sweep at low speed and returns to the park position. If the windshield wiper/washer switch is held in MIST mode, the windshield wipers will continue to operate until the switch is released.

In the desired INT position, the BCM will cycle the WPR Relay  70 ON and OFF to acquire the desired intermittent speed of the windshield wiper motor. The intermittent speed of the windshield wipers can also be effected by the vehicle speed. Refer to Vehicle Speed Sensitive Wipers for more information.

In the INT position 1, voltage is supplied through the following internal resistors to the signal circuit of the windshield wiper/washer switch for the BCM.

In the INT position 2, voltage is supplied through the following internal resistors to the signal circuit of the windshield wiper/washer switch for the BCM.

In the INT position 3, voltage is supplied through the following internal resistors to the signal circuit of the windshield wiper/washer switch for the BCM.

In the Low position, voltage is supplied through a internal 562 Ω resistor to the signal circuit of the windshield wiper/washer switch for the BCM. The BCM will energizes the WPR Relay  70 which will operate the windshield wiper motor at low speed.

In the High position, the windshield wiper/washer switch supplies voltage to both the WPR Relay  70 and WPR Relay  52 coils. This energizes both relays and allows battery voltage from the WPR Relay  70 switched output to the switched input of the WPR Relay  52 through its contacts and out the switched output of the relay to the high speed circuit of the windshield wiper motor. The windshield wiper motor will operate at high speed.

When the wipers are placed in any of the INT positions, the BCM will decrease the wiper delay as vehicle speed increases in order to keep windshield visibility clear. The BCM receives vehicle speed via class 2 from the ECM.

The BCM supplies voltage to signal circuit of the windshield wiper motor park switch. The BCM monitors this signal to determine if the windshield wiper motor is still operating or it has parked. The signal will be pulled to ground by the 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 windshield wiper switch being open.

Wiper/Washer System Description and Operation Rear

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

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.

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.

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.