While driving my truck on the highway at 65 mph the truck bucked hard and immediately downshifted into 2nd gear. This caused me to rapidly decelerate to approximately 40 mph, I am lucky there was not another vehicle behind me when this happened since rapid unexpected deceleration without brake lights is very dangerous. I had to drive the truck in limp mode at 45mph and approximately 4500 rpms to the nearest exit. This event illuminated the trucks check engine light and displayed a brief service 4WD message followed by a permanent reduced acceleration message on the dash.
2024 GMC Sierra 2500: stuck in gear or won't shift
7 of the 108 complaints about the 2024 GMC Sierra 2500 describe stuck in gear or won't shift.
- owner complaints
- 7
- of this car's complaints
- 6%
- recalls
- 0
Stuck in gear or won't shift by model year
What owners say
The control valve body failed. There are so many, that there was a shortage of parts. Had to take it in as it went into limp mode. 34,000 miles. There were dozens of trucks, same year, waiting for the same repair. Shop says probably every truck will need it. It is a known issue.
Constantly having to clean the map Senor to be able to drive pickup without service emissions alerting me to clean the map Senor or my truck goes in limp mode. This can’t be normal to have to clean this so much. My truck is fairly new and should not be having these issues. Put a scanner on my GMC and the code says P122D. I got on YouTube and I found MANY people complaining about my exact problem for quite some time!
The contact owns a 2024 GMC Sierra 2500. The contact stated that while driving 60 MPH, the vehicle went into LIMP Mode. The contact stated that the vehicle then inadvertently lost motive power and was unable to accelerate above 40 MPH. The vehicle returned to normal functionality, but the failure became a regular occurrence. The check engine warning light was illuminated. The vehicle was taken to the dealer, who diagnosed failures with the transmission solenoid and transmission control module (TCM). The vehicle was not repaired. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the federal safety agency Hotline for assistance. The failure mileage was 50,000.
2024 GMC DENALI HD with approx. 12, 500 miles: The truck is constantly going into limp mode. Driving down the road, first it feels like the wheels lock up with a loud noise. Immediately goes into limp mode and check engine light comes on. Took it to the dealer yesterday 6/3/25 for repairs. I just spoke to my service advisor this morning where I was told it was the Valve Body of the transmission that needed to be replaced. However, they were on backorder and have no ETA on when they will get a replacement.
2024 Gmc sierra Denali ultimate 3500hd equipped with duramax lp5 and Allison 10 speed transmission mission. Towing cargo trailer Thursday November 21 up 4 degree incline transmission let loose banged and popped slammed to a stop almost causing accident and went to limp mode. Took to dealership in show low Arizona. Was told this is common problem and it’s the valve body assembly and parts are 60-90 days out. Mind you this truck was ordered from factory and received in march of 2024. The truck has 21k miles. So now a vehicle I bought specifically for business to haul a spray trailer will be down 2-3 months with no loaner to use to operate our business.
First date was 04/23/2024 my truck went into limp mode with an alert reading engine and transmission control module problem. Brought it in and they reset the sensors. Shortly after the alert warning goes off again and I turn the engine off and start it back up. It cleared the alert, I brought it back in on 06/15/2024. They reset sensor and fixed a recall on tailgate. I picked up truck, drove it for 2 months and TCM warning came up and threw truck into limp mode while pulling a 2 horse trailer. It turned a 3 hr drive into a 6 hr drive. I brought back to dealer on 8/19/2024 they had it for 4 days and they notified me that this is an on going problem. It is a transmission solenoid valve stuck open and they ordered the part and told me it could be months before the part gets here due to the ongoing backorder from all the other trucks that have the same problem. I use this truck for work and leisure to pull my boat and 2 horse trailer and now I have a vehicle payment to make and no vehicle to use. I cannot use it to work or anything else because it is at the dealer for an unspecified amount of time. I have read online that this is a major problem with this truck and GMC as well as the dealerships know about this problem and they still sold it to me. There are so many complaints online about this GMC 2500 AT4 truck problem that GMC should stop selling this truck.
Service bulletins that may apply
- This bulletin helps aid the tech in possible 10L100 transmission noise that may be normal or abnormal...
- This service bulletin advises the technician to check if the transmission cooler lines are twisted to...
- This technical bulletin provides a procedure to inspect the front pump of the transmission for a possible...
- This bulletin provides a procedure to add a shim to the rear axle to change the pitch of said axle to...
- This service bulletin helps diagnose/reduce possible CCND issues on Transfer Cases
- This bulletin provides a procedure to replace the triple clutch housing and internals if found the
- Power train
- This service bulletin provides information on the harmful effects of ethylene glycol in transmission fluid.
Related recalls
No recalls on record for this model year.
Questions about the 2024 GMC Sierra 2500 won't shift
Is stuck in gear or won't shift a common problem on the 2024 GMC Sierra 2500?
7 of 108 owner complaints about the 2024 GMC Sierra 2500 (6%) mention stuck in gear or won't shift. The model year with the most reports is 2024.
Is there a recall or service bulletin for this on the 2024 GMC Sierra 2500?
There are 0 recalls and 55 service bulletins for the same area of the car. Check them below with your VIN.
Other symptoms on the 2024 GMC Sierra 2500
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