Transmission Will Not Shift Right When On Interstate

I Have A 1999 S10 With A 2.2 4cyl Automatic. When I Am On The Interstate Driving, After About 50 Miles Or So Depending On How Many Hills I Have To Go Up. My Se Light Comes On And It Acts Like It Doesn't Want To Shift Down. The Only Way It Will Shift Back Down Is To Shut The Engine Off And Start It Back Up. Please Help!!!

Get a code reader and run the code. If it comes up as a trans problem, take it to a trans shop. Automatic transmissions are a pain in the a** to work on and there are many special tools need. Its well worth the money to send it to someone.

Advanceautoparts or autozone might be able to run the code for free. Try autozone first.

Don't take it to a tranny shop until you come back here and post the codes. A lot of times there is nothing wrong with the tranny and the shop will screw you.