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.

- Payson, AZ, USA

Experienced loss of power and inability to maintain highway speeds. The Transmission shifted violently and RPMs went as high as 3500. Was able to move off the highway but cars behind us had to dodge us when it failed. There was warning message on the dash and a CEL. The truck threw two codes P0700, P0747. I was able to limp to a dealer 5 miles away. This is a known TSB with GM. There is a solenoid failure in the Transmission. There is 30-90 day backorder on parts as the failure is so prevalent.

- Cypress, TX, USA

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.

- Wellington, FL, USA

Transmission and transfer case leaking. Masters cylinder ( brake booster) leaking

- Hackettstown , NJ, USA

The Column Shifter that is installed on all 2024 GMC Sierra 2500HDs and 3500HDs poses a potential safety risk to its passengers and other drivers on the road. When the column shifter of the vehicle is in the standard drive position the shifter covers part of the screen and the direct path to the radio volume control dial and infotainment home button. It has been found and replicated that attempting to interact with the infotainment screen UI and the home button/volume control dial the driver may easily accidentally bump the shifter into the neutral position. Bumping this 8000lbs+ vehicle into neutral unintentionally can be extremely dangerous to its passengers and fellow motorists especially when hauling a heavy trailer or load like heavy-duty pickup trucks are designed to do. Bumping the truck into neutral can allow the truck to lose its acceleration capabilities and degrade braking capabilities as the engine would be disconnected from the drive wheels, limiting engine braking and exhaust braking. This kind of braking is commonly used to help stop the truck with heavy trailers and loads. This problem has been commonly referred to in multiple Facebook groups relating to the 2024 GMC Heavy Duty Truck. I personally have not had it inspected by any third party as there is not much they can do to remedy the issue. I personally recommend that General Motors redesign the column shifter in these trucks shortening it to come no further than the diameter of the steering wheel eliminating any interference with the infotainment system and the home button/volume dial. GM shall replace this updated shifter free of charge in all trucks just recently built. For GM's sake, it is important that this issue is remedied ASAP as the truck just began production and there is a limited amount on the road. This is available for inspection upon request.

- Sewell, NJ, USA