some serious problems with transmision

[wyze]

Hi hows it going, new user here, trying to help out my girlfriends dad

he has a 2007 pontiac g6 gt 3.9l sport transmission, monday he was coming home from work, and when he got back into town the transmission was slipping really bad, he called me when he got home, i took the car for a drive, in automatic the car does not advance at all, but when i put in manual mode, i have no problem aside from a little shudder from first

he had already brought the car to gm when it was under warranty, they put in a valve body spacer the first time it was acting up

i was lucky enough to be able to borrow a snapon scanner from work, i pulled the transmission codes, there was no dtc set, but there was codes saved in memory

under "not run or failed this ign cycle"
p0572, p0573, p0711, p0723, p0741, p0742, p0751, p0752, p0756, p0757, p0843, p0973, p0976, p1750, p1820, p1822, p1823, p1826, p2763

after i took the car for a little test drive i got these codes under
"not run or failed since codes cleared"
p0602, p0603, p062f, p0711, p0741, p0742, p0751, p0757, p0843, p1811, p1915, p2763

i know there was a tsb or recall about a wire shorting out inside the transmission, but since there are no dtc set i'm not sure what i can be

anyone might be able to help point me in the right direction?

[wyze]

Re: some serious problems with transmision

So nobody can help?

[dre256]

Re: some serious problems with transmision

I looked up some of your codes and there everything from cruise control circut, shift siliniod circut, over temp tranny fluid and so on. Sounds electrical. Could be as easy as a bad ground wire on the harness of TCM. If Ihad to take a guess its electrical and a short somewheres. Unfortinaly I dont even know where to start looking. I have been here for 7 years and dont remember anyone having this type of issue before.

Sorry not much help for you

[Coupe_GTP]

Re: some serious problems with transmision

I had pretty much the same issue except mine was really slipping any gear pretty much. I would have to go into the manual mode and than it would launch after revving it up some, than it would slip into the gears. I ended up replacing the transmission, and have had no problems in the last 30k miles.

[Eycman]

Re: some serious problems with transmision

I emailed your original post along with a link to this thread to a guy I keep in contact with that's an active GM Customer Service Tech. I believe that if he can't figure out what the issue might be then he might have access to other GM technicians that can help with diagnosing this issue.

Hopefully it's just a loose wire somewhere.

I also invited him to join the site in hopes that he might be able to give general answers to issues that might come up every now and then.

[JNo2007G6]

Re: some serious problems with transmision

I too am having this problem with my 2007 G6. I'm taking it to a GM dealership tomorrow...I am really hoping I don't need a new transmission.....I have about 15 error codes ranging from Po711 to p2763....Help!

[wyze]

Re: some serious problems with transmision

yeah unfortunately I ended up having to have the tranny rebuilt, no quick fix here unfortunately

[JNo2007G6]

Re: some serious problems with transmision

Yes....I had to have mine rebuilt too. The dealership wanted to replace it.... But I saved a couple grand going to a transmission shop...

[GMManof3]

Re: some serious problems with transmision

I'm looking into Milzy to get mine upgraded. I want a transmission to be better than stock performance.