My truck is throwing a TCM P0708 code along with an ECM code but i cant remember the ECM numbers and i keep clearing them with my EFI Autocal but they come right back and my truck gets stuck in wichever gear its in when the codes pop up. The gear indicator light on the dash thats under the PRND to show you wich gear your in, is not on when the codes come up. When the codes come up and i clear them it shifts but its very hard shifts. Ive seen where people have changed their TCM's or either the NSBU switch or whatever. Ive also seen where the TCM P0708 code is a transmission Range Censor. What will fix it? I have to go back to work and pull my camper so i need some help. Dealership wont touch it bc ive got the EFI on it.
Help!! Tcm p0708
- Thread starter Forrest_ray
- Start date
Well the dealer wont touch it bc it has the EFI Live on it. Can i un program it so they can check it and then program it back?
The dealer can read the computer and tell if it was programmed. You might up shit creek.
Im not worried about warranty or anything i just want to get it where they can program a new tcm. If i can get it to where they can program it then i think it will fix my problem. Surely theres some kind of way to put a new tcm on my truck right?
ok mike it has a new tcm on it and still messed up. now its throwing more codes. one is a transmission pressure control solenoid. there is a few more but the tech didn't tell me what they were. i think one had to do with 2nd gear in the tranny. none of this started until i put the efi live on it. it all happened all of the sudden, after i had the efi live on for about 3 days. the dealership doesn't know whats wrong with it they are just going off what their computer tells them and changing out parts instead of fixing whats wrong with it. its got to be something simple i know theres nothing mechanically wrong with the transmission, its never been abused and only has 60,000 miles on it. i don't see how all this happens all at once unless theres some wiring problem or either the efi live. maybe something with the tuning idk. anybody else have these kinds of problems??
You kinda can't be mad at the dealer. While I worked for GM and ran the diesel program there, most guys have NO IDEA how any aftermarket stuff works and they all think that it alters everything and they shy away from it. Unfortunately..
motor ops tuned it and yes we took it on a trial run to check everything and all went well. the dealership is giving me the run around and haven't been working on it like they say they have. i have a good friend thats a salesman there and he has informed me of it. when i call them they claim to have it in the shop working on it and really it will b parked on the side. ill end up spending a couple thousand dollars by the time they get done. its been at the dealership for a week now and only been in the shop 2 times. I'm just trying to see if anybody has had this trouble and what they did to fix theirs so maybe it will help me and i not have to spend so much. I'm stuck on how all of this happened at once. first it was the tcm, now its a pressure control solenoid and sumthing with the trannys 2nd gear. it doesn't sound right to me.
it went from shifting hard and getting stuck in a high gear, to displaying "shift inhibited" and not going into any gear. when it displays shift inhibited no codes come up until it throws a different code for sumthing else. when this happens i can put it in reverse and back up but then have to shut the truck off and crank it back up so i can put it in drive. when i get it in drive it will go but as i come to a stop it will all of the sudden lock the tires up and then u can't put it in any gear you will have to shut it off again.
Duramax tuner is motor ops. Same company. I do not necessarily believe it's tuning related but putting it back to stock tune would help identify if it is, or isnt.