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 B: No Communication With The Navigation System Module (Step B1)
Courtesy of FORD MOTOR CO.
Fig 2: Pinpoint Test B: No Communication With The Navigation System Module (Steps B1 Cont. & B2)