Hey all,

Short back story... bought my 2001 E39 with a dead nav computer, nav screen would only glow black so I swapped in the wife's E46 MKIV computer and voila, my head unit was working.

The only problem... GPS is off by at least 40 miles and travels in the wrong direction when moving. However, shows right outside my driveway if I use the wife's nav computer, so I think I can at least rule out any external hardware failures.

I accessed the hidden GPS menu and get the following:





I haven't tried resetting the battery or anything. Upon initial install I just plugged in the computer and since then it's been about 6 days so the waiting game is up.

Appreciate any feed back as I spent nearly 3 hours going through this page viewing various threads and figured this place would have the most resourceful folks.