general problems of the 2023 GMC Sierra 1500 - part 2

With out any warning the truck stop running at stoplight an would not start back up. We could not move the truck out of the road and blocked traffic for almost 1 hour waiting for the tow truck and getting it loaded on the tow truck (truck would not go in to neutral). The truck is now at the dealer and they are saying that the engine seized up and will need replaced.

The system that is not working properly is the transmission. It is available for inspection upon request. The safety of the vehicle, and myself, was put at risk because the transmission (once warmed up / at least 30-60 minutes of driving takes place) downshifts hard, making a clunking noise, and has at worst given the vehicle a rough nudge/jolt forward upon downshifting particularly from 2nd to 1st gear (it is a 10 speed transmission). This issue, when it occurs, will require me (the driver) to apply extra force to the brake pedal due to the rough downshift / jolt upon shift. The issue is exacerbated when quickly stopping the vehicle causing the transmission to downshift more rapidly. The vehicle's transmission flaws, of which this happens to be one of them, were being looked into at a certified repair facility (dealership). After the vehicle was in their possession 3 days, they informed me that they could not replicated or reproduce the issue. I informed and reminded the following: (1) the vehicle has to be warm and operated for I would state at least 30-60 minutes of driving before the issue arises (2) I have recorded videos of the problematic sounds of the transmission. (3) I am willing to go for a test drive to try to replicate the issue with dealership staff, but the issue is infrequent and the vehicle must be warmed-up and/or driven more than the typical "test drive" for the issue to be observed. The vehicle component has been inspected by a certified repair facility (dealership), but not directly by a manufacturer's direct representative, police, insurance representatives, or others. The transmission is also problematic in another way (rattling at low rpm's during upshift), but pertaining to safety the downshift is most concerning as described above. There were/are no warning lamps or messages. The symptoms of the problem pertaining to the transmission began occurring around 11,800-12,000 miles in my estimation.

Rear axle locked up driving down the interstate at 65mph. Had I been towing, the incident could very well have caused an accident. Truck taken to dealer and was inspected. Gave an error code of p0747. Per the dealer it was caused by a faulty valve body in the transmission. Part is on back order for months to get fixed. Truck is not drivable as it will not go out of 5th gear. Was told that the problem was found in many models from 2020-2024.

Transmission failure upon acceleration through intersection. Engine high revved went into low power mode. Was lucky to not be rear ended with sudden loss of acceleration. Truck would also not go above 40 safely.

While entering the highway from a downward slop exit ramp and towing a trailer, my truck shuddered hard and briefly locked up the rear axle. It immediately went into limp mode with a message that driving speed will be reduced. It also wouldn't shift past 5th gear. When the event took place, the obd2 generated over 20 trouble codes. My local dealer advised I could drive it to them for repair. Upon dropping it off, they now advise it's not safe for driving and they have no eta on the parts to repair the issue. It's now been at the dealer for a week with no update. This is a well known issue that gm refuses to repair or provide a reasonable timeframe for repair. There are countless videos such as this one that show what happens when this takes place. [xxx] [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

The contact owns a 2023 GMC Sierra 1500. The contact stated that when the vehicle was started and shifted into drive(d), the accelerator pedal was depressed, and the vehicle responded slowly. While driving at an undisclosed speed, the vehicle decelerated and stopped unintendedly. The "parking brake” warning light illuminated. The contact stated that once the vehicle had warmed up, the unintended stopping ceased. The contact stated that the failure was intermittent at first but had become a recurring failure. The vehicle was taken to a local dealer where it was diagnosed and determined that the valve body needed to be replaced; however, the part to complete the repair was on a national back order. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was approximately 60,000.

Multiple occasions where the dash lights up while driving, the vehicle will slow down to 40 miles per hour while driving and notes on the dash the truck acceleration will be reduced. It has almost caused accidents while I’ve been driving on the interstate. The truck will jerk and shake and jolt. Multiple sensors have been replaced including drive shaft, crank shaft components and cooling valve components. I’ve also been complained about burning smells and my engine started smoking recently which caused my family to evacuate the vehicle. I believe my vehicle has same issues as the other recall on GMC sierra 2021-2024 with engine issues.

Transmission valve body physical failure causing jerking and abruptly reducing speed to 30 mph. Vehicle is available for inspection safety of driver and passengers included abrupt deceleration changes risking physical injury to persons and sudden loss of control of vehicular speed/acceleration risking accident/collision with or by other vehicles. Vehicle has been inspected by dealership and is awaiting new part for 100+ days warning indicator for service check illuminated but then reset and turned off without incident. Issue with driving occurred with second incidence of service check warning, and vehicle was taken in for inspection/service.

Transmission light has been on & off for a month and half. Had it at dealer twice, dealer will not confirm a problem. Truck shifts and bucks between first and second gear. Makes stopping in traffic difficult as truck will surge and jump when down shifting while stopping. Took truck to aamco transmission shop. Confirmed problem, no new transmission units or rebuild parts are available for the gm 8 speed transmission. Aamco is replacing unit with a used one. This is a company truck also have a second truck having the same issues with half the miles of this unit. In my opinion gm is aware of the issue in that with both trucks at dealer with same issue, they just send me off with no documentation so as to not have a paper trail. Also no new units available makes me believe that gm can not keep up with warranty replacements.

Valve body failure. Truck rear wheels lockup during failure as transmission was unable to get past 6 gear, sending truck into limp mode at highway speeds. Codes p0700 & p0747, no issues before failure. Dealership has replaced the valve body, but the part number model mqc part# 24065353 has not been redesigned and feel this will be a continuous issues to saftey not knowing when it will fail again.

The contact owns a 2023 GMC Sierra 1500. The contact stated that while driving in 1st and 2nd gear, the transmission was slipping, causing the vehicle to jerk. There was no warning light illuminated. The vehicle was taken to the dealer, who determined that the valve body needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and advised the contact to file a complaint with the NHTSA hotline. The failure mileage was approximately 97,000.

Complete engine failure while driving on interstate. Vehicle went into neutral. After rolling to a stop on highway. Vehicle would not go into gear. Tow was unable to put vehicle into saftey mode and had to drag vehicle onto tow bed. At dealership techs were also unable to get vehicle to turn on or go into gear. Dealer advised the engine was complete seized. This happened while traveling on the highway there was no warning or signs of something being wrong. Vehicle simply lost all power and went into neutral while traveling 70mph with 37k on the odometer.

Unknown , I don’t know why are your recalls module.

My check engine light came on so I stopped at a dealership to have it checked out. The dealership in louisiana said it just needed to be updated. So I made the trip to laredo, texas to go to work. The next day the truck went into reduced acceleration and nearly caused me to wreck on the interstate. I had the vehichle towed to the closest gmv dealership. It turns out these vehicles have a faulty engine coolant control valve. The part is on national back order with no eta. GMC is knowingly allow their customers to operate the trucks with this part that is know to fail. I am currently stranded in south texas and I will have to purchase a rental vehicle to get back home to louisiana. GMC will not help me at all with this situation.

The truck stopped in the middle of an intersection with a transmission error code stating it could no longer shift. The transmission was locked and unable shift or move.

The trucks engine completely shut down while going approximately 60 mph while merging onto the highway. The trucks dash flashed multiple times, a ticking noise was heard, it put itself in neutral, and shut the engine off. All power was lost. I did still have brakes. Safety was a concern as there was a vehicle behind me entering the highway too. Cars to my left as well passing at highway speeds. Once I got the vehicle stopped on the shoulder of the highway it put itself in park. It would not restart. The vehicle was towed to a local GMC dealer. There were no warning lights of any kind that came on. No indication that there was a problem. A couple days later I was informed that the truck would need an entire new engine upon inspection. I was also told by the dealer that the truck had no oil at all in it. The engine consumed it internally by their evaluation.

Purchased a 2023 GMC denali, 1500 on January 12, 2025. After about a week,started to hear knocking ticking noises took the truck to the dealership with 20,362 miles . Dealership diagnosed that the lifters on the driver side went bad dealership replace driver side bank , picked up my truck drove it a little over 500 miles and still heard knocking ticking noises. Send it back to the dealership and dropped it off dealership told me they would keep me an update on it. Emailed called have absolutely no idea what’s going on with my truck. The dealership did mention of a possible engine replacement. But did not confirm after many attempts. Trying to attempt to contact the dealership emails phone calls still no answer. Called general motors. They informed me the dealership ordered a new engine for replacement. That definitely worried me and I asked for a vehicle replacement or refund general motors, declined my request. Now I am not so confident in my truck what else could go wrong since the engine is going to be replaced? what about the transmission? could it affect it? I don’t know> the damage was significant in order for the engine to be replaced you just don’t replace an engine just because, there was no light indications that something was going wrong with my truck. I’m glad I wasn’t driving far when I was hearing these noises coming from the engine because the engine could have seized left me stranded who knows could have crashed if the engine came to abrupt stop because of the engine failure. I purchased this truck January 12, 2025 . The total of time that I have had my truck since January 12 has been 15 days. Today is February 6 on Friday, February 7. My truck has been in the shop literally 30 days exactly. Still no update on when it will be ready. This is so frustrating and such a big inconvenience.

Valve body. While driving the vehicle, hard shifts occurred; the vehicle check engine light came on and stayed on while the vehicle went into limp mode. I was able to link to the GMC dealer. The dealer was not and would not inspect the vehicle at that time. I was told I needed to leave or return in two for inspection. The left vehicle was inspected the next day and determined as a value body. The GMC dealer found the part in another state and has the part shipped. I installed the part, had the GMC dealer search it, and performed a recall update.

While under light acceleration, the vehicle violently down shifts causing the rear wheels to briefly lock up around 45mph. The vehicle traction control activates on dry road way but no check engine light is displayed. The dealership claims the valve body in the transmission is to blame and has a three month back order due to several vehicles with the same failure. The safety issue could be when the rear wheels breifly lock up during wet or slippery conditions and could cause the vehicle to lose control causing a crash.

While driving at about 70 mph, the screens in the vehicle went black and the truck had a complete loss of power. The vehicle inadvertently braked to approximately 30 mph and went into limp mode. The check engine warning light came on and the service power steering warning light, the service transmission warning light, the low tire pressure warning light, and the traction control warning light all illuminated. There were also messages displayed on the instrument panel to service 4-wd and reduce acceleration and drive with care. ”.

On Wednesday December 4th 2024 at 5:45 am on my drive to work my engine shut down, truck electronically shifted into neutral, and notified me to restart my engine. After I rolled to a stop in a safe area off the main road I tried to restart my engine, with no success. I then called my local dealership to inform them of the issue, and they instructed me to call onstar and have them setup a tow to their facility. Once the vehicle was delivered it took the dealership 24 hours to determine that the engine had locked up and a replacement was needed. It has now been almost 2 months with no update on my truck or the replacement engine.

Driving truck at highway speed and went to pass a group of slower vehicles on my right. I increased speed to 75 mph and the engine stopped and I had no acceleration. Engine would not shift into neutral and would not restart. I coasted off to an exit ramp and the truck stopped in the middle of it blocking traffic for about an hour. Highway patrol was on site to help direct traffic through the intersection of the off ramp and side road. We sat for approximately an hour before a tow truck could get us out of the intersection. The truck transmission was locked tight and the tow truck had to put the back wheel on skates to move it. I had to pay $175. 00 to this tow truck company to move me approximately 200 yards to a local restaurant where we waited for the GMC provided tow service to arrive. GMC provided tow truck would only tow to nearest dealership which was in weimer, TX. At the time of failure there was no warning. The truck just shut down making loud wining noises since the transmission was still in gear. This was an extremely stressful event and I was worried that someone was going to strike us at highway speed from the rear. Traffic was heavy that day on [xxx] heading [xxx] towards san antonio and most left lane speeds were 75-80 mph and bumper to bumper traffic. The GMC dealer in weimer was very professional and inspected the engine on Dec 2nd notifying me that is was a total failure and would need to be replaced under warranty. The dealer had a new engine in hand within a few days and the truck was repaired with two weeks. I had a couple other issues with the onstar system and the wireless after I picked up the truck and drive it home. I returned it to the dealer and proper parts were ordered to replace a bad control module that had failed during the engine failure. It took some additional time on my own after this was replaced to get my onstar account back up and running correctly. This truck also had "tailgate drop" issues that the dealer fixed. Information redacted pursuant to the freedom of informat.

The engine failed with 15,000 miles on it. No warning lights ever came on. Had the oil changed several days prior. Lost power, but was able to drive to the dealer, but making weird noises.

Fuel pump module failure while driving causing vehicle to stop abruptly while driving at highway speeds.

After driving for a few minutes when down shifting vehicle will lock gears making the rear tires slide until a loud pop. May drive fine for a few miles again then reoccurring at any speed dealer said to drive it on safety concern but I did. Truck has been at dealer for 2 months now. But am aware of more than mine with the same problem at the same dealership located at laura Buick GMC in collinsville illinois.

The vehicle has experienced repeated incidents of sudden reduced engine power and loss of acceleration while driving. On multiple occasions, while traveling at highway speeds, the vehicle failed to respond normally to throttle input and would not accelerate as commanded and loss of power steering making it difficult to turn the steering wheel and apply brakes. One incident resulted in throwing my truck off the road and luckily we nearly avoided a multi car collision and potential pile with my wife, 8yr old daughter and newborn son in the vehicle at high speeds up to 60/70+ mph but despite avoiding a major life threatening accident to us and other drivers, resulted in striking objects, glass and debris on the side of the road causing damage to my vehicle and then sliding to a complete stop in the ditch off the highway. This creates a hazardous driving situation, particularly when merging into traffic or attempting to maintain speed with surrounding vehicles, increasing the risk of collision. The malfunction appears related to the engine, electrical system, and powertrain. During at least one dealership visit, the reduced power condition was recreated and confirmed by service personnel. However, despite multiple warranty repair attempts, the issue continues to reoccur intermittently. Warning messages have appeared at times, including reduced engine power notifications and check engine indicators, though the condition has also occurred without advance warning. The intermittent nature of the defect makes it unpredictable and unsafe. The vehicle has been out of service for more than 30 cumulative days for warranty-related defect repairs related to this and other electrical issues. Multiple repair attempts have not permanently corrected the condition. The vehicle remains available for inspection upon request. Due to the unpredictable loss of acceleration and prior safety incidents, there are ongoing concerns regarding safe operation of the vehicle.

The contact owns a 2023 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the vehicle started to shake abnormally with the check engine warning light illuminated. The contact stated that after arriving at a parking structure, the transmission warning light illuminated. The vehicle was towed to the local dealer where it was diagnosed with transmission failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 15,000.

The truck jolts forward when approaching a complete stop. I have to prepare for it as I decelerate 10mph to 5mph to complete stop.

Engine has stopped a couple of times at low speeds, was able to restart and continue. Engine will occasionally make a "straining / dieseling sputtering sound" when execellerating from low speeds or stop. Transmission will make strange and strained shifts from time to time. This is reaccruing problem that comes and goes over the last approximately 2 yrs since about 9000 miles to current approx 25000 miles.

The contact owns a 2023 GMC sierra. The contact stated that while driving at 25 mph, the vehicle had lost power, the accelerator pedal was depressed but the vehicle continued to slow down. The check engine warning light was illuminated. The dealer diagnosed that the failure was a software update. The vehicle had been repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 7,780.

I am writing to formally file a safety complaint regarding the ongoing recall of the GMC/Chevrolet 6. 2-liter v8 engine and what I believe to be an inadequate and insufficient remedy being provided to vehicle owners. I purchased a brand-new 2023 GMC sierra at4 equipped with the 6. 2-liter engine. I drive approximately 6,000 miles per year and maintain the vehicle carefully. After receiving the recall notice, I promptly took my truck to an authorized GMC dealership for inspection and repair. The only action taken was an oil change to a heavier-weight oil. I was told that everything was “fine” and that no further action was required. I find this remedy unacceptable given the severity and nature of the reported failures associated with this engine platform. Simply changing to a heavier oil does not address the underlying mechanical risks and does not provide owners with meaningful assurance that catastrophic engine failure will not occur without warning. This issue is particularly serious for me because I rely on my vehicle for my livelihood. I am an account sales executive and use this truck extensively for work travel and customer meetings. If my vehicle were to fail unexpectedly, it could cause me to miss critical business meetings, resulting in immediate financial loss and potentially long-term damage to customer relationships and sales performance. The current remedy provides no confidence that such a scenario will not occur. In addition, this recall has materially harmed the resale and trade-in value of my vehicle. Dealerships are now significantly lowballing trade-in offers because the 6. 2-liter engine recall is widely known and prospective buyers are reluctant to purchase these vehicles. Buyers are also aware that any future owner will not receive the benefit of the original powertrain warranty coverage in the same way, further depressing resale value. As a result, I am effectively trapped in a nearly new vehicle that has become difficult to sell or trade due.