Give us more info!
Read my post below. Car at times doesn't shift out of low gear. I have to stop and either turn the car off or let run for a few minutes. Then when I start driving the car shifts with no problem. I have an a new timing belt replace, look at transmission fluid level ( which good). And I still can't figure out what's wrong.
Souds like trans related but Unless you have code showing up i would take it to a few trans shops and see what they tell u. It may be over ur head