Rear Wiper and Washer System

Rear Wiper And Washer System:

The Generic Electronic Module (GEM) allows operation of the rear wiper functions when the ignition switch is in the RUN or ACC position only. When the liftgate or liftgate glass is ajar (ground potential is present at the liftgate and/or liftgate glass ajar switch), the rear wiper is moved to the PARK position (if not in this position) and deactivated. The GEM controls the cycling of the rear wiper motor via two external relays (rear wiper up relay and rear wiper down relay).

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

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

In the interval mode, there are two interval wiper settings to provide the following rear wiper dwell times:
Interval Setting 1 - 12 Seconds Dwell
Interval Setting 2 - 6 Seconds Dwell

When the rear wiper mode/wash switch is placed in one of the intervals, the GEM will activate one rear wipe cycle of the rear wiper motor. Once the wiper cycle has reached the LO position, after the initial wipe, the GEM will start a cyclical timing function with the dwell times specified.

In the low mode, the liftgate wiper motor will cycle the rear motor continuously at a low speed setting.

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

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

In the mist mode, 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.

Rear Washer Hose Location And Routing:

Fluid for the rear washer is supplied by a two-way washer pump located in the windshield washer fluid reservoir in the engine compartment.

The rear washer hose contains a check valve, which is located in the hose that passes through the liftgate in the rear of the vehicle. This check valve holds the entire line full of washer fluid between washer operation. There is also a stand pipe located along the right hand D-pillar of the vehicle. This stand pipe prevents the unintentional release of washer fluid from the rear washer nozzle. If the hose is cut or disconnected after the line was initially primed with fluid, and the washer system is turned on, the stand pipe may fill with fluid. To resolve this, once the hose is repaired, temporarily disconnect the check valve to allow fluid in stand pipe to drain to lowest point in the hose; then reinstall the check valve.