WARNING: This page is about a different car, the 2003 Lincoln Aviator. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Pinpoint Test G: The Parking Aid Module Does Not Respond To The Diagnostic Tool (Steps G1-G3)
Courtesy of FORD MOTOR CO.
Fig 2: Pinpoint Test G: The Parking Aid Module Does Not Respond To The Diagnostic Tool (Steps G4-G7)