The Wiper/Washer System consists of the following components:

Refer to Wiper/Washer Component Views .

The body control module (BCM) controls wiper motor low speed operation, washer pump and high speed operation. The windshield wiper/washer switch supplies a Low or Ground on the signal circuits to the BCM for windshield wiper/washer operation. When WASH, MIST, DELAY, LOW, or HIGH is detected, the BCM energizes the Wiper relay by suppling Low signal 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 WIPER HI relay switched contacts. Since the WIPER HI relay switched contacts are normally closed to the low speed circuit of the windshield wiper motor, the motor will operate at low speed. For HI speed operation the BCM supplies the same Low signal to the Wiper relay control circuit and also supplies a Low signal to the Wiper HI relay control circuit. The Wiper HI relay's normally opened contacts are now in series with the current supplying Wiper relay contacts. The Wiper HI relay normally open contact at this point supply current to the wiper motors HI input.

In the WASH position windshield wiper/washer switch supplies a ground signal to the body control module (BCM). The BCM monitors for a Low signal condition on this circuit to detect when a WASH cycle is requested. After a short delay, the BCM energizes the Wiper 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.

Windshield wiper/washer system MIST operation is identical to LOW operation, except that the MIST switch is a press and release type switch. When the wiper switch is moved to the MIST position and released, low speed wiper motor operation is started and will continue until 1 cycle is complete. If the wiper switch is moved to the MIST position and held, the wiper motor will operate in the LOW mode until the switch is released.

In the MIST position, voltage is supplied through an internal resistor to the signal circuit of the windshield wiper/washer switch of the body control module (BCM). The BCM will energize the Wiper relay which will operate the windshield wiper motor at low speed.

Windshield wiper DELAY operation is a low speed wiper motor function with a variable delay interval between the wiper motor cycles. The DELAY interval is determined by a series of 5 resistors within the wiper/washer switch. During DELAY wiper operation the signal circuit voltage is further reduced through the DELAY resistors. The BCM monitors the voltage on the signal circuit to determine the delay interval between the low speed wiper motor cycles.

If the wiper switch is moved from a longer delay interval to a shorter delay interval, the BCM will command an immediate wipe cycle, and reset the delay timer to the shorter delay interval.

When the wiper switch is in the Low position, voltage is supplied through an internal resistor to the signal circuit. The body control module (BCM) monitors the windshield wiper switch signal circuit, and energizes the Wiper relay which will operate the windshield wiper motor. The wiper motor will operate at low speed, since the Wiper HI relay is de-energized. Low speed can also be commanded with a scan tool, by commanding Wiper Relay on and off. Refer to Scan Tool Output Controls .

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

Windshield wiper motor park operation is controlled by the body control module (BCM) using an input from the park switch within the wiper motor assembly. The BCM monitors the windshield wiper motor park switch circuit to determine if the windshield wiper blades are at the bottom of the glass. The circuit will be pulled to ground by the wiper motor park switch while the windshield wiper motor is operating. When the wiper switch is turned to the OFF position while the wiper motor is somewhere in mid-cycle, the BCM will continue to operate the motor until the wipers reach the park position. If the ignition is turned off while the wipers are in mid-cycle, the wipers will stop immediately where they are. The BCM will park the wipers the next time the ignition is cycled on.

The BCM provides stall protection for the wiper motor by monitoring the park switch. If the park switch does not transition for 3 seconds while the wipers are operating, the BCM will assume that the wiper motor is stalled, and will de-energize the wiper relay until the wiper switch is cycled off and on again.

The power source for the wiper system is supplied from the Fuse Block underhood. The WIPER/WS fuse supplies the current for the drive motor. The WASHER/RVC fuse supplies current to the body control module (BCM) for the control of the washer pump. G100 supplies the ground for the washer pump and washer fluid level switch. Refer to Wiper/Washer Schematics .

G200 provides ground for the following: