No1UKnow

I don't think the transmission needs to be replaced, and I don't think the dealer performed any real diagnostics. I also think it's an electrical issue. I picked the truck up from the dealer and took it to transmission expert. @newdude He pulled all of the codes (see attached). He says he doesn't do electrical, so he dropped it off at someone who does. I'm waiting to hear what they have to say. I've read about wire harness rubbing/chafing with these trucks that causes electrical problems... Colorado Codes from Precision Transmission.pdf

The truck had about 10,000 miles on it when I purchased it in the fall of 2020 for about $31000. KBB seems to think it's worth between $20 and $25k now, assuming a good transmission.

Also, on the BAT Auto Technical Forum, I had a fellow respond in this way, referring perhaps to a possible ground fault sutuation: ok at my shop i have seen this problem ok i would change the fluid if this is a 8 speed use mobil 1 LV HP also and a bottle of Motorcraft XL-3 trust me it work's great on the shudder problem also a new filter now onto the can bus line issue on the driver side down by the frame you should see a big connector just below the manifold check there for a issue unplug and clean good and drive it again see what happend

I typed up my experience - what happened with my truck - and loaded it into CLAUDE AI. I've attached that dialogue here. I don't for a second think that AI is a match for experience and diagnostics, but this response is based on a lot of experience that's made its way onto the web. What do you all think? Is this a good way to think about this problem? Claude AI on My 2019 chevrolet colorado transmission problem.pdf

I wonder as well, why they would send me a text message with links to these suggested procedures totalling over $10,000 without even the slightest hint of how they arrived at these being necessary.

Well, I received a message from the dealer...

Thanks! I'll ask for that. What's the acronym for?

Thank you 'Blazer. I appreciate you sharing your thoughts and experience.

Thanks!

Thanks. I've read this can happen with a loss of communication with the TCM as well.

Hello All! My 2019 Colorado 3.6 LT, 4WD Crew Cab has approximately 77,500 miles and I recently began experiencing the well-known transmission shudder between about 30 and 65 mph. The problem had worsened to the point that I could no longer attribute it to road conditions - and I had decided to bring the truck to the dealer - when recently, I experienced a sudden loss of power while driving at maybe 40 MPH. Several warning lights flashed, the “Check Stabilitrack” message appeared, and the Check Engine, Stabilitrack, and Traction Control icons remained illuminated. The truck regained driving power, but it stayed in a low gear with unusually high RPMs for the speed. (limp mode?) Because I was only about two miles from home, driving slowly, I was able to make it back and run an OBD-II scan, which showed fault codes U0101, P0700, and U0100. My next trip in the truck was to drive it to the dealer the following day. That trip began normally, but after about a mile I experienced another loss of power, along with the same warning lights and the same “Check Stabilitrack” message. As before the truck remained driveable, but again operated at an abnormally high RPM-to-speed ratio and seemed stuck in a single gear. About a mile later, the dashboard lit up once more, this time displaying “Check 4WD.” Soon after that, I arrived at the dealer. I have verified that the truck still has its original factory transmission fluid, which means it has never received the corrective fluid exchange outlined in GM Technical Service Bulletin #18-NA-355. That was Thursday of last week and I've heard nothing yet from the dealer. According to Technical Service Bulletin #18-NA-355 and the build date of my truck, my truck should have the newer LV fluid. I've done a little research and read something about a problem with the wiring harness as well. Anyone have an insights into this situation? Thank you!!