Navigation / GPS does not track properly (SYNC 2)

Although uncommon, this issue is always one of two things:

  • Wheel  Size
  • GPSM Software
Wheel Size
This is where the wheel size does not match what the vehicle is programmed for. These units rely heavily on dead reckoning - using sensors other than the GPS input to determine position. The unit only checks the input from the GPSM on occasion to verify location.
GPSM Software
The GPSM (Global Positioning System Module) that provides the location data to the SYNC module we sent you needs the software updated. Ford has published a SSM indicating that some vehicles may need the GPSM software updated to fix one of several issues - one of which being vehicle tracking issues.
Best practive is perform the master reset and make sure the tires on the vehicle match the size printed on the sticker in the drivers door jam. If they do not, have Ford verify the tire size is programmed into the vehicle. If this is not the issue, have them perform the suggested action in the attached SSM. If you do have the SSM actions performed, make sure they only program the GPSM. Under  NO circumstance should they reprogram the APIM (the module we sent you).