Washer System
WARNING: This page is about a different car, the 2013 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
When the wiper/washer switch is placed in the rear WASH position, the SCCM sends the request to the windshield wiper motor through the LIN . The windshield wiper motor grounds the rear washer relay directing washer fluid to the rear window.