My old tranny lost it's reverse, please don't ask how. So I bought a used one at the junk yard. I installed it, and other than shifting a little rough, it performed perfect. 3 days after driving it, the S (sport light) came on solid, and the tranny was stuck in 4th gear.

The old transmission did the same thing about 6 months after we bought the car. We had to manually shift from 1/2 to D3/D4. I replaced the Speed sensor on the old tranny because it was not reading the speed correctly. This did not fix the shifting problem.

I can reset the ECU and the problem will go away, but it will show it's face again soon...

Any ideas ? Thanks to all...
-blake

 

You need a new control unit most likely. There's a Service Bulletin that addresses this exact problem, along with the newer part #'s for the upgraded units.

 

I tried searching for the service bulletins, but did not find anything. Would you mind finding the link to the bulletin and posting it for me ?

I really appreciate it.

-blake