Pump, Windshield Washer: Operation

The washer pump/motor unit features a small electric motor. The motor is controlled by a hard-wired output from the Body Control Module (BCM). When battery current and ground are applied to the two pump motor terminals, the motor rotates. When the pump motor is energized, the rotor-type pump pressurizes the washer fluid and forces it through the pump outlet nipple and into the washer plumbing. The BCM controls the hard-wired output to the pump motor based upon a hard-wired resistor multiplexed input received from the washer switch circuitry contained within the right (wiper) multifunction switch.

The washer pump/motor unit and the hard-wired motor control circuit from the BCM 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 washer pump/motor unit or the electronic controls and communication between other modules and devices that provide some features of the front and rear wiper and washer system. The most reliable, efficient and accurate means to diagnose the washer pump/motor unit or the electronic controls and communication related to washer pump/motor unit operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.