Reverse Gear Wipe
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 in any position other than OFF (or moisture is detected on the windshield if equipped with rain sensitive wipers) and the transmission selector lever is placed in the REVERSE position, the rear window wiper activates automatically. This feature can be enabled/disabled through the message center. For additional information on enabling/disabling this feature, refer to the Owner's Literature.