Wiper System & Washer System (Service Information): Operation: Front: Notes
The front wiper and washer system is designed to provide the vehicle operator with a convenient, safe, and reliable means of maintaining visibility through the windshield glass. The various components of this system are designed to convert electrical energy produced by the vehicle electrical system into the mechanical action of the wiper blades to wipe the outside surface of the glass, as well as into the hydraulic action of the washer system to apply washer fluid stored in an on-board reservoir to the area of the glass to be wiped. When combined, these components provide the means to effectively maintain clear visibility for the vehicle operator by removing excess accumulations of rain, snow, bugs, mud or other minor debris from the outer surface of the windshield glass that might be encountered while driving the vehicle under numerous types of inclement operating conditions.
The vehicle operator initiates all front and rear wiper and washer system functions with the control stalk of the right (wiper) multi-function switch that extends from the right side of the steering column, just below the steering wheel. Moving the control stalk to a detent position selects the OFF, DELAY (or INTERMITTENT), LOW or HIGH front wiper system operating modes. Pulling the control stalk to a momentary rearward position actuates the front washer system switch, which selects the front WASH mode and dispenses washer fluid in the wipe pattern on the windshield for as long as the switch is held closed. Lifting the control stalk to a momentary upward position selects the MIST (or PULSE) mode, which cycles the wiper blades for as long as the switch is held closed then completes the current wipe cycle and parks the blades at the base of the windshield after the switch is released.
The right multi-function switch provides hard wired analog and resistor multiplexed inputs to the Body Control Module (BCM) for all of the wiper and washer system functions. The BCM then provides the appropriate hard wired control outputs to energize or de-energize the wiper and washer relays soldered onto its printed circuit board. The relays control the flow of battery current to the front wiper motor and washer pump motor, invoking the requested wiper and washer system operating modes. Front wiper and washer system operation is completely controlled by the BCM logic circuits, and that logic will only allow these systems to operate when the ignition switch is in the ACCESSORY or ON positions.
The hard wired circuits and components of the front wiper and washer system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the front wiper and washer system or the electronic controls or communication between other modules and devices that provide some features of the front wiper and washer system. The most reliable, efficient, and accurate means to diagnose the front wiper and washer system or the electronic controls and communication related to front wiper and washer system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.