I've got a 2002 Ford Escape (automatic transmission) that will start fine and reverse without any problems, but when I put it in drive and try to pull forward, it remains in idle. I can hit the gas and take it up to 3000+ RPM, but it just moves forward at about 5 MPH idling, with the O/D light flashing.
However, if I put it in L1 or L2, I can get up to 20 MPH, shift into drive, and it will shift up and down just fine until I come to a stop.
What's causing this? Is it a computer/electrical problem?