2008 Factory nav stays about 200 yards off

[Jus Cruisin]

This is my first Ford nav system. I have had a couple Dodge and a couple GM's and a stand alone Garmin Zumo. My problem is the Ford will not stay "calibrated" to my position. It lags about 200 yards behind me and stays there even when I stop. At intersections the nav shows I have not reached the intersection and when I pull in my driveway, it has me located about 3 houses down the road. When I correct it through the calibration, it will be off again once I start driving. Is there anything else I can do? Or is it a trip to the dealer?

[wiingnut]

I believe there might be an adjustment to make it more precise

[hndacr]

What vehicle do you have? Hold down the "3" and "6" button at the same time until you enter the diagnostics screen. Once in the menu, go into the gps info screen and make sure you are getting a couple of signals. There are a total of 6 satellites, I believe you need three to get a good signal. You may have lost your GPS signal and your system is working off of vehicle speed, map matching, and the gyroscope.