The Wiper/Washer System consists of the following components:

With the ignition in the ON position, accessory voltage is supplied through the 30A WIPER fuse to the wiper ON/OFF relay and the wiper RUN/ACC relay that are all located in the underhood fuse block. With the wiper RUN/ACC relay energized, accessory voltage is supplied to the WPR/WASHER 10A fuse that is located in the instrument panel (I/P) fuse block. Refer to Wiper/Washer Schematics.

G201 provides ground for the windshield wiper motor. G101 provides ground for the following components:

The windshield wiper motor is a 2-speed motor and is operated at LOW speed in all wiper modes except for HIGH. With the ignition in the ON position, accessory voltage is supplied to the windshield wiper/washer switch from the WPR/WASHER fuse located in the instrument panel (I/P) fuse block. The body control module (BCM) controls all wiper motor mist, wash, delay and low speed operations based on inputs received from the wiper/washer switch. The washer pump and high wiper operations are controlled directly by the wiper/washer switch.

When the wiper switch is in the low speed position, battery positive voltage is applied through the switch internal resistor and the wiper switch low signal circuit to the body control module (BCM). In response to this signal, the BCM energizes the wiper ON/OFF relay by applying battery voltage through the windshield wiper switch signal 2 circuit to the coil side of the relay. This allows battery positive voltage from the WIPER fuse to flow through the input side of the ON/OFF relay and out to the switch side of the HI/LO relay. Since the wiper HI/LO relay is de-energized and its switch contacts are normally closed to the low speed control circuit of the windshield wiper motor, the motor will operate at low speed.

Wiper motor low speed operation and the wiper ON/OFF relay can also be commanded ON/OFF by using a scan tool.

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 wipe 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.

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. The body control module (BCM) monitors the voltage on the wiper switch low signal circuit to determine the delay interval between the low speed wiper motor cycles.

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

When the windshield Wash switch is pressed, battery voltage is applied through the switch contacts and the windshield washer switch signal circuit and the body control module (BCM) to the windshield washer pump. The BCM monitors the voltage on the windshield washer switch signal circuit to detect when a WASH cycle is requested so it can also enable the wipers. After a short delay, the BCM energizes the wiper ON/OFF 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.

When the wiper switch is in the high speed position, battery voltage is applied through the windshield wiper switch high signal circuit to both the wiper ON/OFF relay and wiper HI/LO relay coils. This energizes both relays and allows battery voltage from the WIPER fuse to flow through the wiper ON/OFF relay to the switch input of the wiper HI/LO relay through its switch contacts and out to the high speed control circuit of the wiper motor.

Windshield wiper motor park operation is controlled by the body control module (BCM) using an input from the park switch that is located within the wiper motor assembly. The BCM monitors the windshield wiper motor park switch signal circuit, which includes the 10 A WIPER DWELL fuse, to determine if the windshield wiper blades are at the bottom of the glass. During wiper operation, each time the wiper blades are at the bottom of the glass, the park switch is momentarily closed to ground signaling the BCM the wiper position. 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 turned ON.

The wipers will not park when they are commanded ON and OFF with a scan tool. The BCM will park the wipers the next time the wiper switch is turned ON and OFF.