2003 Mercury Mountaineer O/D light blinking and then Servic

While traveling up a sharp incline at work this week, my O/D light started blinking. The vehicle would not move either. I put it in park and tried again and the light stayed on blinking and the vehicle would still not move. I put it in park and shut the engine off re-started it and the O/D quit blinking. I could then proceed up the hill at that time.

This happened two days later. Same thing my O/D light started blinking. The vehicle would not move either and then Service Engine light came on. I put it in park and shut the engine off re-started it and the O/D quit blinking but the Service Engine light stayed on. I could then proceed up the hill at that time.


I had the code read and there was only one. It said "speed sensor"

I just had the transmission replace about 7,000 miles ago. The vehicle was jumpung in and out of O/D before that and the mechanic said I needed a new transmission. It still does not drive right. It slams into gear quite often when shifting from neutral to reverse and it still seems to jump in and out of OD occasionally.