GMC Sierra 3500 transmission problems

POWER TRAIN

The contact owns a 2022 GMC Sierra 3500. The contact stated that while driving 65 MPH and depressing the accelerator pedal, the vehicle hesitated before going into LIMP Mode. A dealer was contacted. No warning light was illuminated. The vehicle was towed to a dealer where it was diagnosed with transmission control valve failure. The vehicle was not repaired. The contact associated the failure with NHTSA Campaign Number: 24V797000 (POWER TRAIN); however, the VIN was not included in the recall. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline to report the failure. The approximate failure mileage was 71,000.

NHTSA complaint #11756953 — an unverified report by a vehicle owner.

POWER TRAIN

Since I purchased this truck in 2023 brand new as a 2024 the shifting has been very abrasive. It shifts far excessively harder than it should and I have brought this to the dealership’s attention many times. Now I am finding out that there is a massive recall on this vehicle’s transmission because of these issues that have been happening. The error codes are P0700 and P0747 The Engine and Transmission System is not performing as expected. An issue has been detected in the Transmission System that transfers power from the engine to the drive wheels. You may experience reduced power or shifting issues.If the vehicle is continually driven with the check engine light on, the emission controls might not work as well, the vehicle fuel economy might not be as good, and the engine might not run as smoothly. This could lead to future repairs.

NHTSA complaint #11753659 — an unverified report by a vehicle owner.

POWER TRAIN

The contact owns a 2026 GMC Sierra 3500. The contact stated that while driving at 35-40 MPH on the interstate and towing a loaded trailer, the vehicle experienced reduced braking performance. No warning lights illuminated. The local dealer was contacted and informed that the brakes performed differently. Additionally, the dealer stated that the transmission was not downshifting. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 500.

NHTSA complaint #11749030 — an unverified report by a vehicle owner.

POWER TRAIN

Have been driving it on four separate occasions and the engine will start running rough and shut off leaving me with no power brakes or power steering. Once when I was going about 30 miles an hour the other three times when I was coming to a stop with a trailer on just took it in Kendall Chevrolet for the first time they are still working on it but unable to duplicate the problem this is a very serious safety concern for myself and possibly for others that have the same issue

NHTSA complaint #11744605 — an unverified report by a vehicle owner.

POWER TRAIN

The contact owns a 2025 GMC Sierra 3500. The contact stated that the transmission was shifting hard and was jerking while shifting gear. Additionally, the vehicle failed to accelerate above 50 MPH. The messages “Reduced Acceleration” and “DEF Low” were displayed. While refueling the vehicle, the fuel gauge failed to correctly display the level of fuel inside the fuel tank until the vehicle had been driven for approximately 20 minutes. The vehicle was taken to the dealer to be diagnosed, and the contact was informed that the transmission needed to be updated. The system was recalibrated; however, the failure persisted. The vehicle was taken to another dealer, George Kell Motors (3808 Van Dyke Rd, Newport, AR 72112); and the system was recalibrated. However, the failures persisted. While driving approximately 60 MPH, the transmission was shifting hard, and the vehicle took over 2 hours to drive 19-miles. The engine temperature gauge fluctuated between 185 and 188 degrees. The vehicle was pulled over to the side of the road to cool down before continuing to drive, while not exceeding 40 MPH. The vehicle was taken to a third dealer, Fremont Chevrolet GMC Riverton (1401 N Federal Blvd, Riverton, WY 82501); who determined that the bell body needed to be replaced. The vehicle was scheduled to be repaired, but parts were on back order. The contact became aware that there was a recall related to failure; NHTSA Campaign Number: 26V129000 (Fuel System, Gasoline); however, the VIN was not included. The manufacturer was not made aware of the failure. The failure mileage was approximately 40,000.

NHTSA complaint #11728507 — an unverified report by a vehicle owner.

POWER TRAIN

My truck has been exhibiting hard downshifting at certain speeds, when the powertrain loads up such as a grade change, and requires a downshift. I have complained about this issue to the dealership as early as 2022, and 33,185 miles. The dealership made me pay for a transmission $388.90 flush which did not resolve the issue. The problem has become progressively worse, to the point where the toll road transponder fell of my windshield during a recent harsh downshifting incident. At the same time there was an existing MIL and derating for a DEF heater and NOx sensor failure, so during a warranty visit I asked that this transmission issue be addressed. On Friday March 13, the dealership called and said they confirmed the hard downshifting, albeit not as extreme as I described. The technician said that the valvebody needs to be replaced. At the same time, they performed a TCM flash for the 10L1000 momentary wheel lockup recall. The dealership then said they could not get the truck to set a P0747 code, said that GM refuses to replace the faulty valve body, and recommended I take the vehicle home unrepaired, and to come back when the P0747 code is set. I requested they continue to drive the vehicle. Today March 20 the dealership called and said they could not get the code to set, and that I need to drive the truck and come back when the code appears, despite the truck exhibiting clear symptoms of a progressively wearing feed limit low valve. N242454441 does NOT seem to indicate a P0747 code is required to replace the valve body. This vehicle is not safe for towing a 20,000+lbs and GMC is refusing to repair a transmission with symptoms congruent with N242454441. The dealership still has possession of the vehicle and wants $360+ in diagnostic labor.

NHTSA complaint #11725965 — an unverified report by a vehicle owner.

POWER TRAIN

August of 2025 [XXX] purchased a certified GMC Sierra 3500. The truck had been traded in May and sat in their service department waiting on a valve body. At this point, we knew this. [XXX] had done research on it, and felt confident in being told the valve body was completely replaced and now working…. Worst mistake we’ve made in a long time. It was not replaced, that was only the beginning of the lies. [XXX] then drove the truck across the country for work, not knowing how much of a hazzard it was. Shortly after arriving there he quickly realized the truck was still having transmission problems. We brushed it off, these things happen. Fast forward when he came home in September/October he took the truck to the Rice Buick GMC service department. Where he was supposed to “wait” on his appointment. Only to call me hours later, they clearly weren’t going to be done that day. We left not knowing that it would be nearly a month until we could drive the truck again. In the midst of that they never offered any help, a rental or anything. When I asked, they offered a tiny small car next door at enterprise. I clearly did not agree, we just spent a lot of money on a heavy duty truck for a reason. It took multiple phone calls to multiple supervisors for them to agree to let him rent a truck. Because you know they might have to spend an extra penny or something (que the eye roll). In that month of having the truck the communication was little to non existent. They never answered the phone, called back, heck most of the time the text messages weren’t even replied to. It once again took me getting a little bit ridiculous for an answer - the truck was “fixed”. When I picked up the truck I spoke to the the service manager, and he of course tried to play me like I was some dumb women who had no idea what I was talking about. He dismissed all of my concerns, acted like having a truck for a month was normal. (More attached in photos) INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11720207 — an unverified report by a vehicle owner.

POWER TRAIN

This 2024 GMC Sierra Heavy Duty has experienced a continuous pattern of major mechanical and electrical failures since early ownership. The vehicle required a complete engine replacement under warranty at approximately 43,626 miles. Since that time, the vehicle has continued to experience repeated injector failures, control module faults, communication errors, and voltage-related system issues. Current diagnostic codes indicate multiple simultaneous failures including ignition relay feedback circuits, control module power faults, gateway communication loss, brake system communication faults, and battery voltage circuit errors. The dealership has diagnosed a power distribution / fuse block failure at approximately 79,000 miles. These electrical failures affect multiple vehicle systems and raise concerns regarding reliability and potential safety risks due to loss of communication between control modules and possible braking system interaction. The vehicle has been in the dealership numerous times for repairs including engine replacement, injector replacement, control module reprogramming, and electrical diagnostics. I am submitting this complaint due to concern over a potential systemic electrical defect and ongoing reliability issues.

NHTSA complaint #11718551 — an unverified report by a vehicle owner.

POWER TRAIN

Rear wheel lockup event in traffic while towing 24000lb 5th wheel on freeway. Vehicle was limped to a dealer, diagnosed as a transmission valve body failure. Repair took over 1 month stranding us over 1500 from home while on a trip.

NHTSA complaint #11714631 — an unverified report by a vehicle owner.

POWER TRAIN

I have a 2023 GMC Sierra HD3500 6.6 Duramax. February of 2025 the valve body failed after 23,000 miles. The failure happened when the transmission had an extremely hard shift at 55 mph and then went into 5 gear limp mode. Computer through code P0700 and P0747. The P0747 is the code that tells you the valve body failed. When I took the truck to the dealer, they would not let me take the truck home because of the high risk of the transmission locking up and causing bodily injury, aka crash. Since the valve body was back ordered, I was warmed that it may be a month to get a replacement and install it. I finally got the truck back after 33 days. To add to the frustration, GM would not give me a loaner truck. They would give me a loaner SUV but that did not have what I needed out of a vehicle.

NHTSA complaint #11711114 — an unverified report by a vehicle owner.

POWER TRAIN

During takeoff the transmission acted as if it was in neutral while I was crossing traffic luckily, the semi truck that was coming towards me was able to stop. I had the vehicle towed to a shop. After the vehicle was towed to the shop the transmission acted normal when the mechanic searched the VIN number. There was a service bulletin issued by General Motors for this exact problem. Had the semi not been able to stop. It could’ve very well killed me or my children. I suppose if it would’ve killed someone, maybe general motors would finally do a recall for this very disappointed in general motors and the NHTSA, the fact that this is an ongoing problem and has not been fixed and as a customer, I was not even notified that this problem existed is very alarming.

NHTSA complaint #11701315 — an unverified report by a vehicle owner.

POWER TRAIN

The contact owns a 2017 GMC Sierra 3500. The contact stated that while shifting from park(P) to drive(D), the engine revved, but the vehicle failed to move forward. There were no warning lights illuminated. The vehicle was towed to a certified mechanic, who determined that the vehicle needed to be diagnosed by a dealer. The mechanic was able to shift the transmission into manual drive mode, allowing the contact to drive the vehicle to the residence. The dealer was contacted and informed the contact that the VIN was not under recall. The vehicle was not repaired. The manufacturer was informed of the failure and referred the contact back to the dealer for assistance. The failure mileage was approximately 120,000.

NHTSA complaint #11688844 — an unverified report by a vehicle owner.

POWER TRAIN

MY TRUCK IS EXPIERANCING THE SYMPTOMS OF RECALL # N242454440 TRANSMISSION VALVE BODY, ITS SHUTTERING BETWEEN SHIFTS AND CLUNKING IM AFRAID OF THE REAR WHEELS LOCKING UP FROM THE HORROR STORIES I HAVE READ THE TRUCK IS AT COULTER GMC NOW FOR EXACT DIAG BUT FROM EVERYTHING I HAVE READ THIS IS COMMON ISSUE FOR THIS RECALL THAT MY VIN DOES NOT FALL UNDER FOR SOME REASON

NHTSA complaint #11686290 — an unverified report by a vehicle owner.

POWER TRAIN

While driving on the interstate we were exiting to pull into a rest area while slowing down the rear wheels momentarily locked up and the truck downshifted hard and abruptly with that happening the check engine light came on along with a decreased power message. We pulled into a parking spot during so we tried to shift into reverse and it didn’t want to shift into reverse, we tried this for a while. We finally got it into reverse and we were able to back out of the parking spot. When we tried shifting to drive we encountered the same issue. The vehicle did not want to go into drive. Once finally into drive it did not want to shift into any higher gears. It was essentially stuck in one of the gears. We made it to a GMC dealer on the next exit -we drove on the side of the interstate to get there- when we arrived we had them run the codes and they told us it was a transmission control valve which GMC has had a major recall on. While we had this “fixed” at a different dealership previously in march of 2025 it only entailed “updating the software” involving the transmission control valve. We had to leave the truck at the GMC dealer that we were able to ‘limp’ to in Crestview FL. We’ve been told our truck now needs an entirely new transmission that is going to cost $7,000. We had a similar issue right after the “software update for the transmission control valve” on march 20, 2025. The software was updated roughly a week before that incident which seemed to have cleared itself because it was momentarily and never happened again until now. Our safety was at risk because we had to drive on the side of the interstate to get to a shop because we were out of town and a tow truck was going to cost between 600-1000 dollars to get home.

NHTSA complaint #11685316 — an unverified report by a vehicle owner.

POWER TRAIN

My rear wheels randomly lock up and truck violently shakes. It does it randomly in very long trips so GM and every dealer I've brought it to just says that "they cant help me because they cant get it to replicate. Had the same issue with my 2020 and it has an open recall for the exact same thing. This is very dangerous and is going to get someone hurt one day if gm isn't help responsible and fixed their valve body failures for ALL of the 10L1000 L5Ps. Not just 2020-2022....it's ALL OF THEM. 2020-2025!!!

NHTSA complaint #11683027 — an unverified report by a vehicle owner.

POWER TRAIN

I'm reaching out for urgent help regarding my 2024 GMC AT4, which is currently at Newby Buick GMC in St. George, Utah, with a transmission failure that occurred on Saturday, [XXX]. While returning from a horse show in Ogden, Utah, the truck began to experience severe transmission issues near Santaquin, Utah, around 5:30 p.m. Just before reaching Santaquin, the truck jerked violently three times-so hard that I immediately checked the camera system inside my horse trailer to make sure one of my horses hadn't gone down. That's how intense the jolt was. I pulled into a gas station in Santaquin and called the dealership right away. At the time, I had three horses on board, it was nearly 100 degrees, and I was hauling a large living quarters horse trailer. The service manager was initially unavailable, but he returned my call shortly and advised me to continue driving to St. George at a steady speed if the truck could manage it. He also warned that it might go into limp mode, and in that case, I'd just be traveling very slowly. My husband was on standby in case he needed to meet me halfway, but I was hopeful that I could make it to at least Hurricane, Utah. I was able to access my GMC app on my phone at the time and confirmed to him that the transmission check light was on, and I was receiving a warning notification on the app indicating there was a transmission issue. I was able to limp the truck as far as Hurricane, where my husband met me. We unloaded the horses into stalls and took both trucks into St. George that night to drop the AT4 off at the dealership. On Monday morning, I contacted the dealership for an update and was informed that the issue was likely related to the transmission valve, and that the required part is on national back order-with an estimated delay of two months or more, but no confirmed ETA. This has been my first GMC diesel. I've always driven Dodge trucks. Over a year ago, I saw the new color GMC released and kept telling my husband how amazi INFORMATION REDACTED PURSUANT TO THE FREEDOM O

NHTSA complaint #11677566 — an unverified report by a vehicle owner.

POWER TRAIN

The contact owns a 2020 GMC Sierra 3500. The contact stated that while driving at an undisclosed speed, the vehicle inadvertently went into LIMP Mode. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed that the transmission valve body sensor had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline for assistance. The approximate failure mileage was 130,000.

NHTSA complaint #11672242 — an unverified report by a vehicle owner.