The Wiper/Washer System consists of the following components:

The body control module (BCM) controls wiper motor operation during intermittent mode and wash request, via an internal relay with the module. The windshield wiper/washer switch supplies battery power directly to the wiper motor for low and high speed operation. The switch also supplies power on the signal circuits to the BCM for windshield wiper intermittent operation as well as during a wash request.

In the WASH position windshield wiper/washer switch supplies power and ground to the washer pump motor. The switch also sends a positive voltage signal to the body control module (BCM). The BCM monitors for a high signal condition on this circuit to detect when a WASH cycle is requested. After a short delay, the BCM energizes the internal wiper relay which will operate the windshield wiper motor at low speed. The wiper motor will continue to operate for a set number of cycles determined by the length of time the wash request switch was held in the on position.

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 the variable resistance value of the wiper dwell switch within the wiper/washer switch. During DELAY wiper operation the signal circuit voltage is further reduced through the DELAY resistors. The body control module (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 the wiper switch the wiper motor. The voltage is then reduced by a resistor within the wiper motor assembly.

In the HIGH position, the windshield wiper/washer switch supplies voltage to the wiper motor.

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. G102 provides ground for the windshield washer motor.