I have a 1994 grand Prix. It has a 3.1 engine. This summer (while hot outside) the transmission started acting up. I am an ASE certified auto mechanic and should be able to fix this issue myself fairly easy, but I am wondering if anyone thinks that I am on the right track. Here is what it is doing...... While in overdrive and doing around 60 MPH, the TCC stops working and soon after the overdrive falls. It then reverts to 3rd gear and will not shift back up to OD. I stop for about 30 minutes to have a bite to eat and get back on the road....... overdrive and lockup works again (for a while) then fails again.
I have replaced the solenoids (thinking the TCC solenoid was bad). I replaced all the solenoids and the PWM. It still does the same thing after it get warm.
Is there a temperature sensor? Can it be bypassed? Is the temp sensor causing the problem? I ask this because it is heat related (as far as I can tell).
Thanks ahead of time for all your help.