Windshield Wiper Operation
WARNING: This page is about a different car, the 2014 Lincoln MKX and 2014 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.
The wiper/washer switch is mounted to the Steering Column Control Module (SCCM). The SCCM commands the windshield wiper motor to activate the appropriate wash, low, high and intermittent modes through a Local Interconnect Network (LIN).
When the wiper/washer switch is in the HIGH position, the windshield wiper motor also receives ground which is hardwired directly through the SCCM (bypassing the logic within the module). This fail-safe circuit makes sure that the windshield wipers function in HIGH speed mode in the event of a LIN communication failure.