I have a 2001 ford excursion 4wd 7.3 liter auto trans. When I back out of my long driveway, often it will not drive forward once I shift from reverse to forward (as if it were in neutral). At this point, I shift down into #1/low, turn overdrive off and it will lunge forward a foot or so at a time enough to get me out of the road at which time I disconnect the batteries to reset the "brain" and it will return to normal. It's obviously some sort of sensor issue, any help/diagnosis would be very appreciated.