Originally Posted by VVTiBob

Well it could be the motor, or it may be the wiring harness, or might be something as simple as a ground gone bad or the panel switch.

There are several diagnostics that can be run. There are seven(7) full pages of diagnostic codes and continuity/voltage tests. So what I'm trying to tell you is if you've already have the NAV display out you've done most of the labor already, unless you're very handy with a V/O meter and can access the diagnostic codes, sounds like its time to take it to the dealer to find out exactly what's wrong. Once armed with the correct diagnosis you can proceed.

I will tell you, the usual result after a tilt failure is to replace the harness or switch assembly BUT without the diagnostic codes it's just a WILD guess.