Transmission/Shifting Won't work 2021 Yukon XL Denali

[mannyp02]

I purchased my vehicle in late March and have had no issues until today (including a 5 hr, each way, trip to the beach). This afternoon on my way home, I had cut my vehicle off for just a minute and then started it back up. Upon starting, I received a text from the diagnostics alert system telling me to "Service the engine and transmission system". Since the vehicle appeared to start normally, I attempted to go into Drive. The vehicle jerked as if shifting into gear but when I pressed the gas nothing happened. I noticed the D didn't light up to indicate it was in drive and the dashboard wasn't displaying D for drive, it wasn't displaying anything, not even P. When I tried to shift into D again, alert came up saying "Conditions not correct for shifting" as if I wasn't depressing the brake pedal. Attempting to shift into any gear, neutral or even pressing the parking brake did nothing or gave me the same alert regarding incorrect conditions. Everything else on the vehicle seemed to function fine. After having no luck for 30 minutes, I disconnected the battery in hopes that it might reset something (OnStar was no assistance). I don't know if it was the battery trick or not but I eventually was able to get the vehicle to register a shift and make it home. I moved the vehicle a few times once home and it functioned fine twice before the same issue occurred again. I haven't d/c the battery yet to see if that works again but I'm going to try it in the morning so that I can hopefully drive it to my dealership for service.

Has anyone else experienced the same issue?

 

[Fireman591]

I purchased my vehicle in late March and have had no issues until today (including a 5 hr, each way, trip to the beach). This afternoon on my way home, I had cut my vehicle off for just a minute and then started it back up. Upon starting, I received a text from the diagnostics alert system telling me to "Service the engine and transmission system". Since the vehicle appeared to start normally, I attempted to go into Drive. The vehicle jerked as if shifting into gear but when I pressed the gas nothing happened. I noticed the D didn't light up to indicate it was in drive and the dashboard wasn't displaying D for drive, it wasn't displaying anything, not even P. When I tried to shift into D again, alert came up saying "Conditions not correct for shifting" as if I wasn't depressing the brake pedal. Attempting to shift into any gear, neutral or even pressing the parking brake did nothing or gave me the same alert regarding incorrect conditions. Everything else on the vehicle seemed to function fine. After having no luck for 30 minutes, I disconnected the battery in hopes that it might reset something (OnStar was no assistance). I don't know if it was the battery trick or not but I eventually was able to get the vehicle to register a shift and make it home. I moved the vehicle a few times once home and it functioned fine twice before the same issue occurred again. I haven't d/c the battery yet to see if that works again but I'm going to try it in the morning so that I can hopefully drive it to my dealership for service.

Has anyone else experienced the same issue?

Sorry to hear about this. Just another problem for this train wreck of a model With all the problems with these 2021s GM is going to give the Edsel a run for it's money LOL

 

[robgreg75]

Sorry to hear about this. Just another problem for this train wreck of a model With all the problems with these 2021s GM is going to give the Edsel a run for it's money LOL

Curios on this one since Ford and GM use the same 10 speed assembled in the co-owned factory.

 

[mannyp02]

Curios on this one since Ford and GM use the same 10 speed assembled in the co-owned factory.

Took me an hour and a half this morning to get my Yukon to shift into gear. No clue what I did (if anything) to make it occur. I d/c the battery again but that didn't seem to work, it was about an hour after I reconnected it that it finally shifted. I had already called Roadside Assistance to tow it to a dealership when I decided to try one more time and it actually worked. Got it to the dealership and left it running while I spoke to them about the issue assuming that it would maintain ability to shift; got back in to move it and couldn't shift out of park (again it didn't even appear to be in Park, no illumination on the shift button and it wasn't shown in the dashboard as being engaged). Tech said he had never seen it before but they'd let me know what they found out although they don't expect to get to it for a few days. I'll update once I find out more.

 

[100cars]

Interested to see what happens with this.

 

[mannyp02]

They finally told me last week that they believe the issue is the ECM (engine control module). It supposedly took several days to determine what it could be as they told me GM hadn't seen this particular issue before. They ordered the part but it has not yet come in so I do not know for sure if this in fact fixes it. I wasn't able to make it to the dealership where I purchased my vehicle, it's being serviced by a closer GMC dealership. Probably a good thing since the place I purchased from has been less than helpful throughout, safe to say I won't be purchasing from them again in the future that's for sure.

 

[B520044]

Mine has just recently started to shake/shudder (more than usual) pretty strongly at slow speeds. Especially during start stop/slow traffic. It's like the transmission cant figure out which gear to be in and grinds. The Yukon shakes as though your driving over rumble strips. Above 40 mpg its ok.

 

[Micahsd]

Mine has just recently started to shake/shudder (more than usual) pretty strongly at slow speeds. Especially during start stop/slow traffic. It's like the transmission cant figure out which gear to be in and grinds. The Yukon shakes as though your driving over rumble strips. Above 40 mpg its ok.

I've noticed that too on my '21 Tahoe...seems like when it's around 1,300-1,500 RPM and going up a slight incline around as you stated, 30-40 MPH. I've got 2,500 miles on mine and it was built in March '21.

 

[thompsoj22]

YIKES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I don't even want to know what you paid for these vehicles. We buy American vehicles because we like them, The manufacturer should like Americans who buy their vehicles, As opposed to beating them into submission and losing another customer to the Japanese competition car/truck! GMC should be rolling out the red carpet for all of you!

 

[mannyp02]

Curios on this one since Ford and GM use the same 10 speed assembled in the co-owned factory.

Interested to see what happens with this.

Took a week and a half to get the ECM in but the dealership got it replaced on Friday. So far, so good, it has appeared to fix the issue. I've put quite a few miles on it since then with no repeat of the issue *knock on wood. While it is frustrating to have experienced this severe of an issue early on in ownership, I'm hopeful that no other issues arise and this was simply an aberration. Aside from this problem, I love the vehicle. I do have some minor gripes (particularly with some features that are considered upgrades and not standard features, even on the Denali trim) but overall my family has been very happy with it.