Principles of Operation (How Does it Work?)

The wiper system has four different operating modes: off mode, low-speed mode, high-speed mode, and interval mode.

In the off mode, there is no windshield wiper motor activity, and the windshield wiper motor is in the PARK position.

In the ON mode, the windshield wiper motor is set to a low-speed setting. The wiper/washer switch provides voltage to the windshield wiper motor through the low-speed circuit. The windshield wiper motor provides ground through a dedicated ground circuit.

In the high-speed mode, the windshield wiper motor is set to a high-speed setting. The wiper/washer switch provides voltage to the windshield wiper motor through the high-speed circuit. The windshield wiper motor provides ground through a dedicated ground circuit.

In the interval mode, the windshield wiper motor is set to a low-speed setting. The windshield wiper interval relay is activated at the beginning of each wipe and deactivated when the windshield wiper motor park switch reaches the run position. The interval relay is part of the wiper/washer switch.

When the wiper/washer switch is in the Interval (INT) position, the windshield wipers will make a single sweep followed by a pause.

If the washer switch is pressed between 100 ms and 300 ms, with the mode switch in the off position, the wiper system will provide one low-speed wipe with no wash.

To engage the windshield washer, push the knob of the wiper/washer switch toward the steering column. When the wiper/washer switch is in the OFF or INT position, the windshield wipers will run as long as the knob is depressed (up to 10 seconds). When the knob is released, the washer will stop immediately, but the windshield wipers will continue to run for two to three sweeps, then return to their previous set operation. Washer engagement does not affect windshield wiper operation when the wiper/washer switch is in the LOW or HIGH position, but the washer will be deactivated if the knob is held for longer than 10 seconds.

Rear Window Wiper Washer
The Generic Electronic Module (GEM) allows operation of the rear window wiper functions when the ignition switch is in the RUN or ACC position only. The GEM controls the cycling of the rear window wiper motor through a single relay (rear window wiper relay).

There are four modes of operation: off mode, interval mode, on mode and wash mode.

NOTE: The GEM does not control the rear window washer, only the rear window wiper.

In the off mode, there is no liftgate wiper motor activity and the liftgate wiper motor will be in the PARK position.

When the wiper/washer switch is placed in the interval position, the GEM will activate the rear window wipe cycle of the rear window wiper motor. Once the wiper cycle has reached the LO position, after the initial wipe, the GEM will start a cyclical timing function.

In the ON mode, the GEM will cycle the rear window motor continuously at a set-speed setting. The GEM provides a ground to activate the rear window wiper relay.

In the wash mode, when the wiper/washer switch is pressed and held for a time greater than 100 ms, the GEM supplies a ground through the wiper/washer switch and will cycle the rear window wiper motor three times.

Fluid for the rear window washer is supplied by a washer pump located in the rear passenger compartment.