Thread: Will the trans out of an 04 Grand Prix fit a 02?

Originally Posted by 01GTP

It will fit yes, but it will not work due to pcm issues.

Man i'm screwed....I just went and got new fluid and filter put in this morning and it was ok....I even ran a few errands and it was ok. But later in the afternoon I went to go to the store and it was shifting hard...The messed up part of this is it wasnt doing it this morning before the fluid change. I called the trans shop and they told me to bring it by in the morning to read the trans....So then I called a friend thats a certified master Gm tech...he told me I could reset the ecm which i did by disconnecting the battery....which worked fine for a while but it started shifting hard again!!!!

Originally Posted by FoSHO99

You would need a certain pcm and a certain modified database to flash a 03 pcm file to your car to put a 03+ trans in a 02 or below.

Who changed the filter/fluid and what did they change it with? Did you check the level of the fluid now or what the fluid was like before you changed it?

A trans shop thats highly recommended...i'm thinking the factory suggested fluid... I checked it earlier and it was full....it had a burnt smell before i changed it but wasnt all that dirty...