Code U0100 service Stabil Trac and reduced engine power?

DDSCHMIDT50

MEMBER
2012 GMC TERRAIN
2.4L
4 CYL
2WD
AUTOMATIC
105,723 MILES

It all started with a service Stabil Trac and reduced engine power the codes I received were p0191fuel rail pressure sensor and p0506 idle speed reduced
I have since replaced the high pleasure sensor ( what a pain it's under the intake) I changed plugs and coils replaced both cam and crank solenoids cleaned the intake and throttle body I wrapped the intake with sound deadening foam for insulation ps it does have a foil layer. Ran good for a few days and runs good while driving the problem happens when I come to a stop then I get the errors again. I bought a cheap obdll scanner (elm 327) now since I've cleared codes, I'm getting just 2 errors obdll code u0100 and transmission control module code u0100. I haven't been able to locate the tcm the part I googled doesn't seem to be the same. So, I don't really know where the TCM is.

Any help would be greatly appreciated.
Since this is my only vehicle, I'm kind of in a pickle.
Thank you in advance for your time and help.
Regards,
David

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
47,512 POSTS

The transmission control module is located inside the transmission and when it is starting to go out it will cause the limp mode you have described. This guide can help with more information:

https://www.2carpros.com/articles/reduced-power-limp-mode

You will need to remove the transmission pan to replace the TCM. Here is how the job is done make sure to clear the codes once completed. Check out the images (below). Let us know if you need anything else.

Images (Click to make bigger)