when ever you let all the way off of the throttle at 50 mph or greater the transmission downshifts out of od into third and the torque converter stays locked up so you wind up with engine breaking. It does not do this when the engine temp is less than 180 degrees (cold start) only at normal operating temp. It does not do it if you lock out od, I have cleaned the battery cables and the ground wires. changed out the trans. relay, and wrapped the striped cable that runs over the alternator with foil all with no change. Is there some sensor or solinoid that I need to check?

 

Now my truck has added a new symptom. It still works fine until the engine reaches normal operating temp but after that it does not want to shift into od until 55 or 60 mph. this has gone from a great truck to drive to one that is a real pain to drive. I took it to a transmission shop and all they wanted to do was to overhaul the tranny. It is not slipping and is not running hot. I don't think I trust this shop to work on my truck.

 

After much trouble shooting ( a special thanks to Dave Gorend for his help) It turned out the tranny had to be rebuilt. the problem was not electrical it was that the od was shot. hopefully this will help some one else.