GMC Sierra Complaints

15,732 consumer complaints on file.

#11726026March 21, 2026
SERVICE BRAKES, POWER TRAIN, FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
While driving at approximately 60 mph on an open road with no obstacles present and no braking input, the rear wheels spontaneously locked up without warning. No brake pedal input. No warning light prior to the event. No obstruction in the road. The vehicle has been subject to an active manufacturer recall for rear wheel lockup due to transmission control valve failure. The dealer's own diagnostic system generated a report showing six active fault codes in the following days including lost communication with the Brake System Control Module and Transmission Control Module. These codes were not addressed on the repair order. The dealer attributed the lockup to an Automatic Emergency Braking activation without diagnostic confirmation and performed no repair. The manufacturer's own internal bulletin dated January 22, 2026 acknowledges the exact fault codes present on this vehicle as a known defect. The dealer cited this bulletin to dismiss the concern while stating no problems exist. A persistent brake noise has been confirmed by two separate authorized dealers across three visits with no repair performed at any visit. The vehicle has required five dealer visits in 77 days of ownership with 1,729 miles. The defect remains unresolved and poses serious risk of loss of vehicle control at highway speed.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725751March 20, 2026
POWER TRAIN, ELECTRICAL SYSTEM
Truck broke down with a rear-wheel lockup and had the transmission replaced in June 2025. In December 2025 and February 2026, truck lost power two times and entered limp mode while on a major highway and major interstate. The problem was misdiagnosed in June 2025, diagnosed properly in December 2025, but not properly repaired, and diagnosed properly in February 2026. All three times the vehicle had this issue, two of the same exact DTCs were present. This is a safety defect, and I have lost all confidence that the vehicle is reliable enough and safe enough for myself and my family.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725796March 20, 2026
POWER TRAIN, FUEL/PROPULSION SYSTEM
The DEF tank in my truck is defective and its the second time in the last 14 months it has broke. The part is now back ordered and according to the dealership this is a nationwide issue regarding these specific trucks. I have contacted around 10 dealers in my area and all tell me the same thing that they have multiple trucks waiting on the same issue. I have not had my truck for over 2 months and have no idea when i will be getting it back due to dealership having no idea when the part will be released due to the back order. This seems to a huge issue with these trucks and GM is doing nothing to help resolve it. I've reached out to GM directly and get no assistance and now have made 2 payments on my truck and the dealership refuses to give me a loaner vehicle. i am looking for some help or relief on what to do to go about my issue
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725848March 20, 2026
ENGINE
My Truck Was 123369 Milles Was Driving And Stop At My Work Turn Off The Vehicle and After That Re-Start The Vehicle And The Vehicle Not Start The Check Engine Light Coming on Im Tow The Tuck To The Dealer Were I Do All My Service They Check The Truck After A Mont And They Told Me The Engine Timing Off Due To Camshaft Gear Spun On Camshaf Which Sheared Locator Pin Valve Timing Off So That Enging Does Not Build Compression In Any Cylinder Recommende Enging Replacement Due To Nature Of Failure-Extensive Mechanical Damge Internaly To The Camshatf And The Warranty Was Over
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725920March 20, 2026
ELECTRICAL SYSTEM
Vehicle battery dies and dealer cannot source issue. Voltmeter shows large fluctuations in voltage while vehicle is running and driving.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725938March 20, 2026
STRUCTURE:BODY
The grill deflector flew off the truck doing 80mph on hwy130 in Austin, Texas.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725965March 20, 2026
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725474March 19, 2026
POWER TRAIN
since we have had this truck the transmission has not worked right to where no longer works plus we have paperwork from other dealship have said this truck should have never been sold to us by the other deal they told us this truck has a lot of issues and is not road safe we where told by that dealer they cant help us so we need help with this the truck don't even have 100,000 on it the truck also pulls to the light sometimes and sometimes to the right .....
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725605March 19, 2026
ENGINE
The 10L80 transmission had a catastrophic failure just outside of the GM warranty. At under 70K miles the pump gears came apart and sent metallic debris throughout the entire transmission and exhaust gaskets converter next to the transmission. These will need to be replaced. I have found multiple cases online with this 10L80 transmission where there has been significant problems with these transmissions blowing up or even causing momentary lockup with the wheels. This transmission is notorious for problems but has not yet been recalled. My mom and nephews were in the vehicle when it broke down putting their safety at risk on the the highway. This problem was confirmed by the GMC dealership here in Ruston, LA. The dealership has done the mechanical inspection. The engine started making an extremely loud noise and the warning lights did not even come on until I attempted to start it later after the breakdown.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725620March 19, 2026
FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL, FORWARD COLLISION AVOIDANCE: WARNINGS, LANE DEPARTURE: WARNING
A few weeks ago my adaptive cruise stopped working, as well as the automatic high beam system (not sure the technical name). As there was a warning light displayed, I brought it into the dealership to have them check it out. The technician jumped in really quick, made some changes within the control panel, and the light came off. As I drove out and tried to use the adaptive cruise control, it didn't work and I almost went into the back of a truck. That all being said, I brought it back into the dealer last week for them to diagnose the problem as a failed front windshield camera. I find it hard to believe that this camera can fail at 50k miles, and the repair with parts and labor costing approximately $1000. This is an advanced system designed to improve the driver experience and heavily marketed. Considering this is tied to safety in some capacity, shouldn't GM cover this repair? I quickly googled the issue and found others have had the same failure. The camera system combined with the control panel covers so many applications, I would be concerned about other issues with the truck. Not to mention the massive recall of my L87 engine and water pump failure that I have also dealt with. I appreciate you taking the time to read my rant. Not sure if this will do anything, but it would be nice to have some sort of relief from the OEM due to the issues I have already experienced owning this truck.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725695March 19, 2026
UNKNOWN OR OTHER
When my android auto does not connect, it essentially disables the whole infotainment system which is incredibly distracting and dangerous while driving. I am requesting that this be fixed so that I can still use some of the infotainment system but they are redusing to to do anything to fix the issue. The dealer has advised that they are unable to fix the issue because it is software related but yet the software team is saying it is a dealer issue. Please help me get a resolution to this issue!
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725704March 19, 2026
STRUCTURE:BODY, UNKNOWN OR OTHER
While driving 65mph in my 2024 GMC Sierra Denali Ultimate on Interstate 270 in Hilliard, Ohio my chrome grill deflector just flew off and hit my windshield. It then went over my truck and almost caused a major accident with the cars and semi-trucks behind me. I was lucky to maintain control of my own vehicle! It appears to me that the mounting fractured and it looks like manufacturing defect. Looks like the same issues recalled in 2022 year models. How many have to die before GM fixes this issue? They now want $1,500 for a new grill on my 2024 truck.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725126March 18, 2026
ENGINE
While driving at 72moh, the engine started to knock/tick and then shifted into neutral indicating to press the start button again. Once I coasted to a stop, the truck shifted into park by itself and indicated to hit the start button again at which point it was completely locked up and inoperable. The vehicle had an engine replaced at 13,000 miles and currently has 54,000 miles on it. It now needs another complete engine replacement. The vehicle also had the recall inspection done in DEC/2025 and found no issues.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725162March 18, 2026
ENGINE, POWER TRAIN, FUEL/PROPULSION SYSTEM
Bought truck 0n 12/26/2025 from lot in Michigan had it transported to Missouri. First time I drive it Check Engine comes on and goes into "Limp Mode". Had it towed to GM Dealer and they say it was the high pressure fuel pump. Got it back and check engine light comes back on then goes off then back on again. Not happy at all!!!
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725236March 18, 2026
ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:UREA INJECTION SYSTEM (DEF)
The contact owns a 2020 GMC Sierra 1500. The contact stated that while starting the vehicle, the engine hesitated while turning over. The vehicle started with the check engine warning light illuminated, and the DEF (Diesel Exhaust Fluid) sensor light was illuminated. The message “94 miles before vehicle enters LIMP Mode" was displayed and instructed the contact to see the Diesel Exhaust Fluid section of the Owner's Manual. The vehicle was restricted to a 65 MPH max speed. The vehicle was towed to a dealer, where it was diagnosed, and it was determined that the DEF tank pump assembly had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 121,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725266March 18, 2026
ENGINE AND ENGINE COOLING
The contact owns a 2021 GMC Sierra 1500. The contact stated that on Aug. 14, 2025, the PICO engine test was completed on the vehicle under NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling). The dealer stated that the engine had passed the test, and the engine oil was changed to a higher viscosity oil, and the oil cap, oil filter, and the page in the Owner’s Manual were updated. The contact stated that the vehicle was making abnormal sounds while idling, and the fuel consumption had increased. The dealer was contacted and advised the contact to bring the vehicle back to have the engine test performed again; however, the contact refused. The vehicle was not repaired. The contact stated that the engine test had not been performed on the vehicle and that the vehicle was unsafe. The manufacturer was informed of the failure and informed the contact that the vehicle was repaired. The failure mileage was approximately 44,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725286March 18, 2026
ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:UREA INJECTION SYSTEM (DEF)
The contact owns a 2024 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the fuel level indicator on the instrument panel became inoperable and provided incorrect information. The contact stated that due to the inaccurate fuel level, the vehicle almost went into LIMP Mode with the message “Refuel - EMPTY Now” displayed. The vehicle was taken to the dealer, where it was diagnosed, and determined that the DEF tank had failed and needed to be replaced. The vehicle was not repaired. The contact was informed by the dealer that parts to repair the vehicle were on backorder. The manufacturer was made aware of the failure. The failure mileage was approximately 34,895.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725355March 18, 2026
ENGINE, POWER TRAIN
My 2024 GMC Sierra 1500's engine has gone bad, and needs to be replace after only 71,000 miles, and this is only 90 day after already replacing the transmission
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725375March 18, 2026
ENGINE
The contact owns a 2024 GMC Sierra 1500. The contact stated while driving 35 MPH, the vehicle shut off while making a turn and started shaking abnormally. Several unknown warning lights were illuminated and the contact pulled over to the side of the road and turned off. The vehicle failed to restart. The vehicle was towed to the dealer and was diagnosed, and it was determined that the engine had seized and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 25,524
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725387March 18, 2026
ELECTRICAL SYSTEM, UNKNOWN OR OTHER, STEERING
I had this truck as brand new for approximately 24 hours when it had a major failure. It had 450 miles on it at time of purchase, but was sold as new. While driving at 45MPH it had a check engine light, service power steering message, lost power steering, lane departure system failure, and reduced power amongst several other lights on the dash. I limped the truck into a gas station parking lot. After turning the truck off, it would not restart. I unhooked the battery for a minute and hooked it back up. The truck did restart with no messages or check engine light. I was able to safely get it to the dealership. As a result of this issue, I forced the dealership to cancel the trade.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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