Wiper and Washer Systems: Description and Operation

An electrically operated Intermittent Windshield Wiper and Washer System is standard safety equipment. The Windshield Wiper and Washer Systems include the following major components, which are described in further detail within this service information:
- Body Control Module - The Body Control Module (BCM) (6) is located in the engine compartment on the passenger side inside the control module box.
- Heated Washer Nozzle Thermoswitch - The thermoswitch is mounted to the under side of the cowl grille.
- Multi-Function Switch - The multi-function switch (2) is secured to the left side and near the top of the steering column, just below the steering wheel. Only the control stalk for the multifunction switch is visible; the remainder of the switch and control circuitry is concealed below the steering column shrouds.
- Washer Fluid Level Switch - The washer fluid level switch (6) is located in the washer fluid reservoir, behind the right front inner fender liner.
- Washer Nozzles - Two heated washer nozzles (4) are secured into dedicated openings within the cowl grille at the base of the windshield.
- Washer Plumbing - The plumbing for the washer system consists of rubber hoses and molded plastic fittings. The plumbing is routed from behind the right front inner fender liner, through the right side of the plenum, up along the underside of the cowl grille to the washer nozzles.
- Washer Pump/Motor - The washer pump/motor unit (5) is located on the lower and forward side of the washer reservoir, behind the right front inner fender liner.
- Washer Reservoir - The washer reservoir (5) is concealed behind the right front inner fender liner. The washer reservoir filler neck is the only visible portion of the reservoir, and it is accessed from the right side of the engine compartment just forward of the battery.
- Wiper Arm - Two wiper arms (1) are secured with attachment nuts to tapered and threaded studs on the ends of wiper pivot shafts, near the base of the windshield.
- Wiper Blade - The two wiper blades (1) are secured with an integral latch to the wiper arms. When the system is not in operation, the wiper blades are parked on the glass at the bottom of the windshield.
- Wiper Module - The wiper module (3), except the two pivot shafts, is concealed within the cowl plenum beneath the cowl grille. It includes the module bracket, three rubber-isolated mounts, the wiper motor, the wiper motor crank arm, the wiper linkage and wiper pivot shafts.

WINDSHIELD WIPER SYSTEM
The Windshield Wiper System will operate when the ignition switch is in the ACC or ON/RUN position and the multifunction switch lever is rotated to the intermittent, low, or high positions. The Wiper System completes the wipe cycle and parks the wiper blades in the lowest portion of the wipe pattern when the multifunction switch lever is rotated to the OFF position. Fuses, located in the Underhood Accessory Fuse Block protect the circuitry of the Wiper System and the vehicle. The wiper motor has permanent magnet fields. The speeds are determined by current flow to the appropriate set of brushes.

The Wiper System in addition to low and high speed has a constant intermittent delay mode. The amount of delay is controlled by the Body Control Module (BCM) and is not adjustable.

The mist function is available by pressing the end of the multifunction switch lever inward toward the steering column to the point of resistance. If the multifunction switch lever is held in, the wipers will continue to operate. If it is pressed inward momentarily then released, the Wiper System will only cycle once. A mist and wash function is also available if the multifunction switch lever is pressed inward past the point of resistance momentarily. This will operate the washers and cycle the Wiper System twice, then return the wipers to the park position.

The most reliable, efficient, and accurate means to diagnose the BCM inputs and outputs related to the various Wiper System operating modes requires the use of a DRB III(R) scan tool.

WASHER SYSTEM
The Washer System is activated by pressing inward on the multifunction switch lever whenever the ignition switch is turned to the ACC or the ON/RUN position. The multifunction switch lever must be pressed past the point of resistance for at least 0.5 seconds to get the washer system to cycle. Holding the multifunction switch lever switch depressed will operate the wipers and washers continuously. Releasing the switch will stop the washer pump motor, but the Wiper System will complete the current wipe cycle, followed by several more wipe cycles (�1) before the wipers park. If the wash switch is pressed momentarily with the wipers in the OFF or INTERMITTENT position, a pulse wipe cycle consisting of two wipes will occur.

Fluid is gravity fed from the washer reservoir to the washer pump motor. The washer fluid is forced by the washer pump motor through rubber hoses to the cowl grille mounted nozzles which distribute the fluid streams on the surface of the windshield. The washer pump motor, washer nozzles, and washer reservoir are serviced separately.