Pinpoint Test F: DTC C1748 - Switch Input Circuit Short to Gnd: Notes
WARNING: This page is about a different car, the 2007 Ford Pickup, 2007 Ford F550 Super Duty, 2007 Ford F450 Super Duty, and 2007 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Refer to appropriate WIRING DIAGRAM ARTICLE, Parking Aid for schematic and connector information.