hannibalhector, Here's a link to another thread about sat. reception.
http://www.explorerforum.com/forums/showthread.php?t=353565&highlight=diagnostic+mode
From what I understand you need four or more satellites to get a fix.
Also just caught a little bit of some tv show talking about onstar and nav and they said besides nav receiver there are wheel and body sensors sending info to the onboard computer to help inprove positioning. Guess that's why when you loose signal while driving it still knows where you are for a little while before sending you into a lake.
Peter, Here you go.. (from Baxterdown 08/2011)
How to put MFT - MyFord Touch into diagnostics mode
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So, a friend gave me a tip yesterday. To enter MyFord Touch (Limited with Sony radio) into diagnostics mode:
- Make sure there is no CD in the system
- Set MFT to AM/FM
- Press and hold the eject button and...
- Immediately after press and hold the right arrow on the center wheel while still holding the eject button
- Hold both buttons pressed for about 12 seconds
- Screen goes black and MFT enters diagnostics mode
The system defaults to a speaker tone test which starts immediately. You can cancel it on the screen.
PROCEED AT YOUR OWN RISK!