[Robbie Hahn]

Hello everyone, I am a new member, wow, this is a huge forum. This is awesome.
I hope someone can give me good advice. I just bought a used 96 deville , and the transmission wont shift into overdrive. So the car will only run about 40-50 mph. I have 3 questions, one is will it hurt it to drive it like that in city driving where I wont exceed 40 mph anyways? Will it get worse overtime and just quit running altogether? Would changing the transmission fluid and putting in an additive help any? It has 129k mileage and is a very beautiful car. Thanks for your help anyone. Robbie

 

[Robbie Hahn]

I forgot to add, the previous owner said the transmission shop said the tranny was failing "to trip the senior". So I dont have clue what that means either, hope that helps.

 

[Submariner409]

Go to the top of this forum's main page - the Deville threads. There are several "sticky" threads there. Open the one titled "How to pull codes" and study: Your car has its own built-in code reader/scanner/memory, all accessed from the center console control buttons. Study and practice, pulling all codes and writing them down. Note whether each is Current or History. Now return to the sticky and open the link with "obd2" in the address - this will take you to a Master Index of all P,B,C, and U code definitions. Write down any code definitions and come back and post it all here.

You may find one or two codes which point to either an Internal Mode Switch or 1-2 or 2-3 shift solenoids. Those aren't too hard to repair. Just about anything else is expensive and not easy at all....................

DO NOT put any snake oil in the transmission. Fix it properly.

BTW............. Welcome Aboard !!!:highfive:

 

[Eric]

In town I always drive with selector in 3 (trans OK and D works) - a common practice and should not hurt anything.