Wipe-After-Wash Mode

When the control stalk of the right (wiper) multi-function switch is pulled rearward to the front momentary WASH position for more than about one-half second while the wiper system is not operating, the SCM sends an electronic washer switch  status message to the FCM, which directs battery current and ground to the washer pump/motor and energizes the wiper on/off relay. This will cause the washer pump to operate in the front wash direction and operate the wiper motor in a continuous low speed mode for as long as the WASH switch is held closed (up to about 10 seconds). When the control stalk is released, the FCM de-energizes the washer pump/motor, but allows the wiper motor to operate for two additional wipe cycles before it de-energizes the wiper on/off relay and parks the wiper blades near the base of the windshield.

If the control stalk is held rearward for more than about 10 seconds, the FCM will suspend washer pump/motor operation until the stalk is released for about 2 seconds, then cycled back to the WASH position; however, the wipers will continue to operate for as long as the WASH switch is held closed. The FCM monitors the changing state of the wiper motor park switch through a hard wired wiper park switch sense circuit input. This input allows the FCM to count the number of wipe cycles that occur after the wash switch is released, and to determine the proper interval at which to de-energize the wiper on/off relay to complete the WIPE-AFTER-WASH mode cycle.