I think there is a gremlin living in my 2019 AT4 6.2 - NUMEROUS ISSUES - HELP!

[Northeast4050]

Sorry in advance for the long winded post here, I am looking for help...and lots of it. 

 

I've got a 2019 AT4 with the 6.2l and it has been nothing but problems since I purchased it. It started early on in its life with the speedo having a mind of its own bouncing up and down when on cruise control but the truck wasn't actually changing speeds. The check engine light came on and it was brought to the dealer - cleared codes and couldn't replicate it and sent me on my way. 

 

Months later more issues - this time my low fuel light came on (had a full tank) followed by the service electronic stability control warning, a warning telling me steering assist was reduced and to drive with care along with the traction control off light and the check engine light. Brought it in to be checked and dealer said there were no codes and they could not duplicate the issue and sent me on my way. For whatever reason they wouldn't tell me why the check engine light was on. 

 

Less than two weeks later the transmission stopped shifting properly - 60mph and felt like the e brake was on, revving very high...check engine light came back on and had it towed back to the dealer. This time they found codes....A LOT OF CODES...they said a number of the modules were not talking to the ECM. They reset all of them, test drove it and said it was fine. The next morning they fired it up and it duplicated...the check engine light was back on with a number of different modules not communicating with the ECM. They were completely unsure what to do and called GM's tech line and they provided them an update for the ECM saying they didn't think it would fix it but it was worth a shot. They kept the truck a few more days, couldn't duplicate it again and returned it to me. 

 

Two weeks later (November 28) driving up the highway and the fuel light error comes back on along with all the steering and traction warnings. This time I also got trailer connection errors (but I wasn't towing a trailer). The check engine light came on but when I got to my destination all the lights turned off and it seemed ok again.

 

Fast forward to today and as you may have guessed, driving up the highway and more issues. This time it was everything at once...every light I've seen and haven't seen on the dash, traction and steering warnings, reduced power, throttle wouldn't work...I limped it to the side of the highway and it died. Wouldn't start but everything electrically seemed to have power. Had it towed back to the dealer...and there it sits. I've attached a photo of today...it shows some of the lights that were on but not all...it kept resetting itself and new lights came on and off, it was very strange. 

 

Has anyone seen ANY of these similar issues and had any success working through them? I know its a lot...it really sucks. The first new truck in my life...my dream truck and it's been nothing but a problem. 

 

16,000 miles, only 93 octane fuel as recommended...and I baby this thing. 

 

Thanks in advance...

[Jay P]

Look at this. Weird electrical issues. May not be your issue but it's easy to check.

 

Jay

 

 

BUELLTIN.pdf

[Jac365]

There were a bunch of recalls related to computer functions. Many people experienced all kinds of warnings, brake issues, etc. that lead to the recalls and computer updates in 2019. I can think of 3 recalls (2 computer updates) that were done to my AT4 in late 2019 early 2020. I did not have issues prior to the recalls but they were done anyway.

[Grumpy Bear]

                                                            Sorry, couldn't help myself. 

 

[Sir Dan]

Please, please try a different dealership for repairs before you get too discouraged. They are not all the same by a long shot....

[Northeast4050]

47 minutes ago, Sir Dan said:

Please, please try a different dealership for repairs before you get too discouraged. They are not all the same by a long shot....

Good advice...I'm on #2 now and am good friends with a service manager at another and have been running it all through him too...he's thinking they need to send an engineer from GM to look into it. Giving the current dealer a chance to see what they come up with...I'm done with the "We reset everything it should be good now" answers. 

[Northeast4050]

13 hours ago, Jac365 said:

There were a bunch of recalls related to computer functions. Many people experienced all kinds of warnings, brake issues, etc. that lead to the recalls and computer updates in 2019. I can think of 3 recalls (2 computer updates) that were done to my AT4 in late 2019 early 2020. I did not have issues prior to the recalls but they were done anyway.

All recalls done thus far...maybe something else will come out that will be the magical fix. Thanks for the suggestion, I appreciate it. 

[Northeast4050]

13 hours ago, Jay P said:

Look at this. Weird electrical issues. May not be your issue but it's easy to check.

 

Jay

 

 

BUELLTIN.pdf 1.02 MB · 7 downloads

Thanks, I'll look into it and suggest the dealer do the same. 

[Glockman40]

If possible, keep an old Toyota on hand to use while your newer vehicles are being serviced/repaired. I keep an old 1987 pick up with the 4 cylinder stick for farm and reasons like yours. Be patient, they don't build them like they used to

[Kclyatt]

I checked same thing after CEL with numerous codes at only 83 miles!  All 4 were not even close to the 53 in/lb torque.....and at one point I had to recheck the torque setting because it was 6-8 full turns per bolt before the wrench clicked!

 

If you don't have in/lb wrench just give it a go with 1/4  inch drive ratchet and tighten each an alternating number of turns until they stop to ensure an even seating.

 

Another possibility and more difficult to find: GM is having issues in the fleet with chaffing/rubbing/cut wiring harnesses in the engine bay.