OK, i'm goin crazy here folks....94 12 valve automatic that for some reason has no overdrive. Had it at a transmission shop and they tore the trans apart and said it is fine. I just got done replacing the TPS and that didn't help either. I read a bunch of threads about adjusting the TV cable but all the pictures looked like a first gen set up and not a second gen. Trans shifts fine except for not going into overdrive....bout to go out of my mind here...any suggestions?

 

I'd pay really close to the "trans temp". Monitor it with a scan tool. Used to have a resistor to plug in the connector to "fool" the pcm so it would allow, but can't remember the resistance off the top of my head.

 

1000 ohm resistor in the trans temp sender plug will fool the PCM into thinking the trans is at 100 deg.

 

Well...took it to a buddys shop and it took him all of 20 minutes to find a broken wire near the trans...ran a new wire and switch and now we have overdrive! Thanks for the input guys.