2024 GMC SIERRA 1500 Power Train Problems

While traveling down the highway at approximately 60-65mph I pressed the accelerator to change lanes and pass a tractor trailer when it felt like my transmission slipped very abruptly. There was a very noticeable power loss and the truck would not accelerate. Then I noticed a loud knocking noise coming from the engine. No check engine light or any other indications on the dash to let me know there was a problem. I began to try and merge to the right of the highway to get off which was not easy do to the power loss and heavy traffic on the highway at the time. I made it to the right lane to exit the highway and when I slowed down the engine died and I had to coast to a stop luckily on an exit ramp. The truck was towed to a dealership and they state that I will need a new engine. I know this issue is already well documented with the GM 6.2l engines but I is very unsettling that the engine just died on the highway at highway speeds and no indications.

On October 23rd at approximately 0900-0915 hours I arrived at a friends house located at [XXX] . As I normally do, I pulled up into the driveway which has a pretty significant incline. I shifted the column shifter into park, and turned off the vehicle via the push button ignition switch. The parking brake/hill brake system automatically engaged as per normal operation. I exited the vehicle and before I could shut the door, the vehicle began to roll backwards. The driver's side door hit me in the right shoulder which pushed me to my left and caused me to roll my left ankle due to the down slope of the driver way. While I felt immense pain in my right ankle, I was able to jump back into the truck and slam on the brakes, causing both rear wheels to lock up and skid in the driveway. I then turned back on the vehicle, noting that the transmission position was still in park, and the parking brake/hill brake was still engaged. I had to disengage the push button parking brake/hill-brake, shift the vehicle from park into drive to move back up the driveway. This time I ensured that the vehicle did not move after following the exact same steps. My truck under went an approximately 30 minute software "upgrade" approximately 2.5 weeks ago. I believe there was an issue where the park sensor did not fully engage, leading the vehicle to believe it was still in an operational gear, however it does not explain how it was able to not only over-ride the parking/hill-brake itself, as well as allow me to shut the vehicle off and exit the vehicle. This safety hazard has caused me an injury that has already caused me to miss 48 hours of work (I am a federal firefighter) and will require more missed time should surgery be required. There were no warning lamps, the backup camera was not engaged, the only audible sound was the beep that the vehicle makes when engaging the parking brake automatically. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Excessive vibration while driving particularly during gear changes. Vibration occurs across different speeds and gear changes.

The contact owns a 2024 GMC Sierra 1500. The contact stated that while driving approximately 65 MPH, the vehicle rolled over a bump in the highway, and the message to "Slow Down" was displayed on the instrument cluster. The contact heard an abnormal metal-on-metal sound coming from the vehicle. The contact had taken the vehicle to a local dealer who diagnosed the vehicle and determined that the supports for the differential and the rear axles had been improperly attached and had become loose. The contact had asked the dealer if the repair could be covered under warranty, and was advised that the repairs were not covered. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 48,000.

Mileage: 48,000

My car is having the same issue as many other 2024 GMC Sierra owners. Reverse gear is not working. It is due to the transmission valve body being faulty. Why GMC has not send a recall notice yet. Are they waiting for someone die in a car accident in a highway, it looks like it affects other gears too. a quick list [XXX] [XXX] [XXX] [XXX] [XXX] [XXX] my car is only 10000 miles. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

10 speed transmission isn't shifting right in the lower gears has a wining noise

The contact owns a 2024 GMC Sierra 1500. The contact stated that while vacationing in Canada and driving at various speeds, the vehicle jerked, and the vehicle failed to accelerate as intended while depressing the accelerator pedal. In addition, the RPM fluctuated, and the engine revved abnormally. The contact stated that the vehicle failed to reverse(R) as intended. The contact was able to coast to the side of the road while in LIMP Mode. The vehicle was towed to a dealer, where it was diagnosed, and it was determined that the transmission had failed and needed to be replaced. The contact was informed that when the dealer contacted the manufacturer to order a new transmission, the manufacturer refused and informed the dealer to repair the current transmission. The vehicle was repaired. The contact stated that a week later, the vehicle experienced another failure. The contact stated that on a separate occasion, while approaching a stop sign, the brake pedal was depressed, and the engine revved unintendedly. The contact used force to depress the brake pedal. The failure persisted. The vehicle was taken to a dealer back in the USA; however, no cause for the failure was found. The vehicle remained at the dealer unrepaired. The manufacturer was notified of the failure and was awaiting the results of the diagnostic test. The failure mileage was approximately 9,000.

Mileage: 9,000

On 22 April I turned my truck in to the dealership service department due to recall of the L87 6.2L engine. Also, told the rep, "my truck was shifting hard". After inspection revealed the valve body needed replacing. My vehicle is still at the service department today with no remedy in sight. I asked if Gm could just replace my transmission because, the part is not coming. They explained they would replace the transmission, but they can't find a 10 speed transmission available to swap out. I call weekly to get updates. nothing!!

Transmission failed during acceleration leaving me in the middle of intersection almost hit by a semi truck that had to slam breaks. Then final shifted and redlined 6 times before shifting. Then proceeded to limp mode

The contact owns a 2024 GMC Sierra 1500. The contact stated that while attempting to reverse out of a parking space, the transmission failed to respond while in reverse. Additionally, the vehicle operated in LIMP Mode. The vehicle was driven in LIMP Mode to the nearest dealer, who diagnosed the vehicle and determined that the transmission valve body was faulty and needed to be replaced. The transmission valve body was replaced. The vehicle was towed back to the residence from out of state. The manufacturer was notified of the failure. The failure mileage was 6,400.

Mileage: 6,400

There is an active recall regarding the safety of my vehicle. NHTSA: 25V274 Manufacturer: N252494000 I contacted GM and was told to see a dealer to have my engine replaced. The dealer is refusing to remedy the recall and pointed me back to GM stating that "GM told us not to service this recall because there isn't yet a remedy". I'm stuck with a very unsafe vehicle that is less than 1 year old and the manufacture is refusing to honor their own recall.

Vehicle jolts forward when coming to a complete stop causing vehicle to move forward unintentionally.

New truck with only 5K miles had the check engine light come on. Sluggish/low acceleration and unable to put into reverse. Towing required to service center.

Transmission valve body failure 10,672 miles ..

On [XXX] this vehicle was in Blue Cruise on [XXX] in Louisiana when it without warning coasted to a stop after the engine quit. Cruise lights remained active, no other lights were illuminated, and the vehicle simply rolled to a stop. La. DOT assisted. The vehicle was towed (complicated that once placed into park, and the engine would not restart, the vehicle cannot easily be placed in neutral to be towed). The vehicle was trailered some ~50 miles and sits at Rainbow NorthShore GMC in Covington, La. This is a series, life threatening situation that all vehicles need be removed from the road. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6

Metal fragments in engine oil. Vehicle has 9500 miles. Manufacturer tells me to keep driving until it fails.

Q1: Engine lost propulsion Q2: I was stuck in middle of highway Q3: Yes, engine needs replacement Q4: Dealer Q5: No, check engine light came on once lost of power

# 11648853 issue started on [XXX] I just experienced the same issue yesterday, and left it at dealership. Transmission fails to shift, upon entering highway, and concerned about being struck from behind. GMC dealer claimed to have addressed the issue at 4785 miles, and now 4 weeks later, at 5196 the same issue started again. I felt a slight shudder, and then loss of power, and "Reduced Acceleration Drive with Care" came on instrument panel, along with check engine light on. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

As I pulled away from a stop sign, my vehicle started surging and went into limp mode, I pulled over to the side of the road to get out of the way of traffic and could not drive in reverse as I tried to park safely on the shoulder of the road. I had to have truck towed and deealership stated there was an issue with the transmission control valve and it would need to be rebuilt. Performed GM TSB 25-NA-014.

My motor seized and shut off while driving 63 mph on a busy highway going up hill. Truck made it to the top of the hill before it shut off and had to coast to a stop on the side of the road. No warning lights or anything. Rpms locked at 3000 and wouldn’t go up or down until the motor shut off. Switched itself to neutral while it was rolling still and wouldn’t allow my to put the truck in park when stopped. Finally locked itself in park and wouldn’t allow to be shifted to neutral. Dealership said the motor seized and ordered a new one but is on back order

While driving I experienced a loss of forward momentum, and watched the RPMs go up to 3000, wording came on the dash, but I was in traffic and wasn't able to read. I was able to reach next light about 1/4 mile, and stopped. Mad a left turn and within 200 feet, same issue. I pulled over and called OnStar. Towed to dealer. Dealer put on lift right away, as it was just in for 1st service on Saturday, with 4775 miles. Dealer informed me of a bulletin out for removing transmission pan, and splitting plates to check a ball size for 6th gear, which they found during the computer diagnostic checks. They claim to have a part tomorrow, and will install soon after.

Truck just made a year old and killed on me in the middle of road. They are saying I need a new engine and maybe transmission. Could not shift truck into neutral, which left me stranded on busy road. For unsafe and had me nervous. Trying to get GMC to buy me out of this vehicle. Had same problem with 6.2 liter prior to this truck. Engine and transmission was replaced. They promised if I bought new truck, I wouldn’t have the issues and here I am again. This is terrible.

DEF tank heater, diesel exhaust fluid heater has failed which causes the truck to go into a reduced speed until fixed. GM has no parts to fix the issue! at my dealer. Currently there is three or four trucks waiting on the exact same part, it puts the truck into reduced power and speed until part is replaced

The vehicle was traveling over a hill, and it failed to shift gears downwards when traveling over the hill. The vehicle’s RPM’s shot up to 4000+ and jolted the truck forward without pressing the gas pedal. The vehicle made a loud noise and would not accelerate in the middle of the road. The vehicle would only accelerate after giving it minimal gas from the pedal. The truck then failed to accelerate on the entire drive to the destination and failed to enter reverse upon arriving to my destination.

Driving on the highway vehicle installed out in the middle of the road lucky I had enough speed to rush to the median. I heard noise coming from the engine while I was coasting off the median on the median. Try to turn on the vehicle no luck.

First time it happened was on November 28th 2024 around 8pm, turned de engine on, selected the reverse gear and stepped on the gas, the reverse gear was selected but the gear didn't worked at all. I almost hit a car that was passing on the street. I out the gear on drive and got the message "reduced acceleration". I believe that is a known issue by GM's 10 speed gearbox. The car is at the dealership and they informed me by e-mail that the part transmission valve body is in a "do not sell list". I have concerns about safety because losing power on a 70miles per hour road can be dangerous and not being able to reverse is also very dangerous. There are tons of posts about it in Facebook.

I have experienced several occurrences of unintended acceleration while operating the vehicle at low speed. Two recent examples; 1) the truck accelerated rapidly while I was driving into my garage, and 2) the truck accelerated suddenly when pulling forward out of a parking spot in the morning shortly after starting the vehicle. In all cases, a hard application of the brake pedal slowed the vehicle. I considered whether this was operator error, possibly engaging cruise control inadvertently while turning the steering wheel, but the incident this morning does not support that potential cause. I have not spoken to the dealer about this issue.

The contact owns a 2024 GMC Sierra 1500. The contact stated while driving 74 MPH, the vehicle inadvertently lost motive power, after which the vehicle was unable to accelerate above 25 MPH. The contact was able to pull over to the shoulder of the roadway and turned off the vehicle. After restarting the vehicle, 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 a failure with the shift solenoid valve and that the serial data gateway module needed to be reprogrammed. The vehicle was not repaired. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 24,000.

Mileage: 24,000

7500 miles and transmission valve body failed. Parts are on back order with no eta.

The transmission would just give out. It also wouldn’t reverse. The cause was a faulty body valve that gm can’t produce fast enough.

On December 25, 2024, my vehicle completely stalled in the middle of the highway while travelling at 65 mph. Fortunately there were no vehicles travelling in close proximity to me at the time as my speed rapidly decreased. The abrupt stall required me to pull over to the side of the road to attempt to restart. I was unable to restart the vehicle despite numerous attempts. Jump starting was also unsuccessful. I was left stranded 90 miles away from home in freezing temperatures during a snowstorm on Christmas night. My vehicle was towed to a dealership 140 miles from home as GM would not cover the cost of towing to the dealer closest to my home (68 miles away). After numerous phone calls with GM as well as the GM dealer, I was informed 9 days later that my entire engine (6.2L V8) would need replaced. I was also informed that there are two vehicles ahead of mine that require replacement of their engines and that the engines are back-ordered. They have been unable to provide an estimated timeframe on when my vehicle will be returned to me in working condition, stating it "could be months." When I was informed of the need for an engine replacement, I placed a request for a manufacturer repurchase which was ultimately denied the following week. The agent responsible for managing my case informed me that "GMC requires two to three major failures" before they will consider a repurchase approval. The dealership was not able to provide me a loaner vehicle and I was informed that GM only reimburses $44 per day toward a rental vehicle. My occupation and location require reliable transportation in harsh winter conditions so a truck is the only reasonable option. The dealership charges $75 per day to rent a basic truck. Prior to this incident, the vehicle did not have any major issues and received routine maintenance services as recommended by the manufacturer. It was never involved in any accidents. It only had 17,553 miles and was purchased brand new in October 2023.

See attached document for complaint.

See attached document for complaint.

On 12-26-24 the transmission on my vehicle failed suddenly going down the highway. Driving down the road a jerking motion and then all of a sudden the vehicle would not shift gears. Luckily the road wasn’t crowed because all of a sudden the vehicle slowed and would not accelerate. If someone had been following me there was no break light indicating I was slowing down. When I returned home I discovered I didn’t have reverse either. If I was in a place I needed to back up I couldn’t have. I took the vehicle into the dealer the same day and they diagnosed the problem was in the transmission. They ordered the part but it isn’t available and don’t know when it would be available. This leads me to think there must be many other transmissions with the same problem as mine. In my case there was no accident but if it had been on a congested highway there could have been.

Failed transmission; needs valve body replacement but part is on national back order. Vehicle has been at dealership since 11/12/24. Almost 2 months and no eta when part will be in. Dealership did offer loaner after first 3 weeks. Vehicle is available for inspection, no safety issues as the problem occurred in driveway at home. If the problem had happened on the highway though, there would definitely have been some safety concerns. No prior warnings or symptoms. The problem has been confirmed by the dealer and was approved as warranty work. A recall should be issued.

On December 13th 2024, I was unable to drive my truck in reverse. I put the truck in neutral and pushed it out of its parking spot. I was able to drive the truck to the GMC dealership for diagnosis. On December 19th, I received a call from the dealership and I was told the transmission valve body was bad. I called on January 2nd 2025 for an update on the repair and was told the valve body was on backorder and they had no ETA on the Part.

The contact owns a 2024 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the transmission shuddered. The contact stated that the shuddering was severe, causing the transmission to seize. The vehicle was taken to the dealer where the failure was identified, and the contact was informed that the transmission fluid needed to be flushed and refilled. The transmission fluid was flushed and refilled; however, the failure reoccurred. The vehicle was taken back to the dealer; however, the failure was not duplicated. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. Additionally, the contact stated that the vehicle remained at the dealer for three weeks and a loaner vehicle was provided; however, the vehicle experienced the same failure. The manufacturer was made aware of the failure and a case was filed. The failure mileage was approximately 4.

Mileage: 4

Called multiple dealerships and found out there is a known problem with the valve body for the transmission in these vehicles, which mine is currently being towed today to the dealer. This is what happened to me today, I was driving with my two children on the interstate and all of a sudden I had no drive nothing so the speed reduced quickly. Well behind me there was a 18 wheeler on my back and almost ran into me because I had no more drive on my pickup. Then when it was safe to pull to the side of the road found out there is no reverse either. Making it even more unsafe to drive these vehicles. If I need my reverse to back my vehicle out of on coming traffic’s I would not be able to do so. But this is the big kicker, this valve body for these vehicles are not being produced by gm. The multiple dealer ships that I called have said all the same thing, this is an extreme safety issue that should be recalled.