GMC Sierra Complaints

15,732 consumer complaints on file.

#11688990September 22, 2025
ELECTRICAL SYSTEM, STRUCTURE:BODY
--Radio power button inoperative --Radio channel change buttons, to left of steering wheel inoperative (everyday) --Radio volume inoperative -just stops working (sometimes) --Radio “HOME” button, left of radio power button inoperative --Driver door mirror wobbles when above 50 MPH (very distracting when driving) --Driver door hard to close and out of alignment --Dealership is selling the vehicles KNOWING some of the issues are present, but not advising the buyer. My safety is/was at risk due to having to move my hands off the steering wheel to touch the radio display to make any changes while driving. A certified GM service dept confirmed all my issues and could not repair. They quoted a PIT 6408. However, this particular PIT does not address my issues/concerns.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11689015September 22, 2025
ENGINE
The engine coolant control valve on my 2020 GMC Sierra 1500 with the LM2 Duramax diesel failed. The failed part is still in my truck, which remains at the dealership awaiting replacement. The repair is delayed due to the part being on nationwide backorder, further highlighting that this is a widespread issue. When the valve failed, the truck entered reduced engine power mode while I was traveling on the interstate. This limited my speed to about 40 mph while climbing a hill. The sudden loss of power in high-speed traffic created a serious safety hazard, as it significantly increased my risk of being rear-ended or involved in a collision with faster-moving vehicles. I drove the truck directly to the dealership after the incident, where the problem was immediately confirmed. The issue was diagnosed and confirmed by the dealership, which identified the coolant control valve as the failed component. To my knowledge, GM has not yet inspected this specific failure. Prior to the loss of power, the truck displayed a “Reduced Engine Power” warning message and the check engine light on the dashboard. These warnings appeared at the time of the failure. Importantly, GM has already acknowledged this issue by issuing Special Coverage N252508341 for 2021 and 2022 GMC Sierra 1500 trucks with the same LM2 engine and the same coolant control valve part numbers. However, the 2020 models (like mine) were excluded from that program despite using the identical part and engine configuration.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688680September 21, 2025
ELECTRICAL SYSTEM
The transmission control module stopped working leaving the vehicle unable to be driven and no part support from gmc/allison and part is backordered with no eta. There are reports the module becomes defective due to its placement near engine heat. There should be a recall for this issue. Many people are experiencing this issue
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688722September 21, 2025
BACK OVER PREVENTION: WARNINGS, ELECTRICAL SYSTEM
Every time I pull the truck into my garage or a parking stall at low speeds while using the front park sensor it will shut off with the automatic start stop while still in motion. Then you have to let off the brake pedal for it to start and sometimes the vehicle will search forward.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688564September 20, 2025
SUSPENSION
Rear right clunk in rear suspension. Dealer kept truck for 2 days and can't figure it out. Worried it could be a suspension nut or bolt and could cause a crash.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688635September 20, 2025
POWER TRAIN, ENGINE, FUEL/PROPULSION SYSTEM
2020 gmc sierra 1500 elevation 5.3l engine. Lifter failure due do faulty design I’m afm/dfm systems.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688270September 19, 2025
POWER TRAIN
Transmission failure at a little over 120,000 miles while towing a side by side on the highway. This highway has a speed limit of 80 which is dangerous when the vehicle stops working properly for myself and any other drivers in itself. Earlier this year the transmission had been updated due to a recall and was deemed to work good by the dealership but didn’t notice any difference. Had an engine light pop up a couple hours before but no messages or any other signs to inform me of the issue and was still working fine with no struggle until it gave out
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688289September 19, 2025
ENGINE
Driving 30 MPH on 4 lane city road when engine shut off with many warning lights. Vehicle dead in the road, needed to be towed to dealership where I was informed that the engine had "locked up" They said they have seen many of these 6.2L engines locked up.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688302September 19, 2025
ENGINE
On August 17, 2025 while traveling north on the Garden State Parkway in New Jersey, my vehicle suffered a catastrophic engine failure without warning. Fortunately, I was able to get off the roadway without incident. This is the SECOND time this has occurred in the past 4 months. (1st NHTSA Complaint 04/18/2025 #11655375) This second engine failure occurred with less than 6000 miles, and only about 3 months of driving. As of this report, the vehicle has not been repaired.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688303September 19, 2025
ENGINE, POWER TRAIN, SERVICE BRAKES, HYDRAULIC
The contact owns a 2017 GMC Sierra 1500. The contact stated that while driving approximately 55 MPH, the vehicle started losing motive power. The accelerator pedal was depressed and the engine revved; however, the vehicle failed to respond as intended. There was no warning light illuminated. The contact pulled over, and after several attempts, the vehicle restarted. The contact was able to drive the vehicle to a local dealer and failed to exceed 10 MPH. The dealer was able to diagnose the vehicle and determined that the torque converter had failed and needed to be replaced. The vehicle was repaired. Additionally, the contact stated that while driving approximately 35 MPH, the vehicle started vibrating and stalled. The contact stated that again, there were no warning lights. The contact was able to restart the vehicle and drove the vehicle back to the same dealer. The dealer diagnosed the vehicle and determined that the fuel injectors had failed and needed to be replaced. The vehicle was repaired; however, the fuel injectors failed, and the contact had taken the vehicle to a different dealer. The vehicle was not yet diagnosed or repaired. The contact stated that while driving approximately 65 MPH, the brake pedal was depressed but was difficult to depress. The contact allowed the vehicle to coast and was able to pull off the road. The contact slowed down to approximately 2 MPH and was able to use the parking brake to stop the vehicle. The vehicle was turned off and restarted to reset the braking functionality. The contact was out of town and took the vehicle to a dealer to be diagnosed and repaired. The manufacturer was informed of the failure. The failure mileage was approximately 24,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688357September 19, 2025
POWER TRAIN:AUTOMATIC TRANSMISSION, AIR BAGS
The contact owns a 1995 N/A GMC Sierra 1500. The contact stated that after parking, turning the vehicle off, and exiting, the vehicle suddenly rolled forward, down a slight incline, and crashed into another parked vehicle. The cause of the failure was not determined. The manufacturer and local dealer were not contacted regarding the failure. In addition, while making a left turn into an intersection, a second vehicle crashed into the front of the vehicle. During the crash, no air bags deployed. The contact sustained injuries to both the shoulder and the chest. No medical treatment was required. A police report was filed at the scene. The cause of the failure was not determined. No further information was available. The VIN was not available. The failure mileage was 4,000.
Crash:
Yes
Fire:
No
Injuries:
1
Deaths:
0
#11688359September 19, 2025
ENGINE, POWER TRAIN
The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at various speeds, the vehicle jerked abnormally while depressing the accelerator pedal. A dealer was contacted. The vehicle was taken to the dealer, and the technician informed the contact that the failure might be related to the engine or transmission; however, the contact was informed that the vehicle needed to be inspected to determine the cause of the failure. The vehicle was not repaired. The contact stated that the failure had occurred several times. The manufacturer was notified of the failure and informed the contact to file a complaint with the NHTSA Hotline. The approximate failure mileage was 41,248.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688413September 19, 2025
ELECTRICAL SYSTEM
Onstar Module Failed.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688037September 18, 2025
SERVICE BRAKES, ELECTRICAL SYSTEM, ENGINE
I purchased a 2025 GMC Denali a few months ago. At approximately 7,000 miles, the front brakes failed unexpectedly and were replaced by the dealership. However, by 14,000 miles, I began experiencing brake issues again. Before I could return the vehicle for service, I was driving on the turnpike when the engine suddenly seized without warning. This created an extremely dangerous situation—vehicles behind me nearly collided as I lost power and control. I managed to pull over safely, but the tow truck operator struggled to load the vehicle due to all four wheels locking up and the engine being completely seized. Once the vehicle was inspected at the dealership, I was informed that the engine had failed and would need to be replaced. I am aware of the recurring issues associated with the 6.2L GMC engines and related component failures, and I no longer feel safe driving this vehicle. Given the repeated mechanical failures and the serious safety risks involved, I am formally requesting that GMC initiate a buyback of this vehicle. I believe this situation qualifies under lemon law protections and warranty obligations, and I urge GMC to take immediate action to resolve this matter.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688147September 18, 2025
SERVICE BRAKES
While trailering a large RV the information center sent me two warnings. The first was trailer brakes disconnected the second was service trailer brakes. Took it to the dealer they were unable to replicate so they blew me off.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688158September 18, 2025
STEERING
The contact owns a 2017 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed and coming to a stop, the steering wheel seized. There was no warning light illuminated. The contact stated that while attempting to make a turn, the steering wheel became difficult to maneuver. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 118,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688161September 18, 2025
ENGINE
One of the lifters collapsed resulting in catastrophic engine damage
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688167September 18, 2025
POWER TRAIN
Torque Converter failure confirmed by dealer: was driving at high way speeds when I noticed a slipping sensation from the transmission upon any sort of acceleration. No warning lights were illuminated or any symptoms leading up to the failure. This could have potentially caused me to lose any form of acceleration that would enable me to get off of the highway or away from a situation requiring sudden acceleration.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11688172September 18, 2025
ENGINE AND ENGINE COOLING, STEERING, SERVICE BRAKES, HYDRAULIC
The contact owns a 2023 GMC Sierra 3500. The contact stated that while driving approximately 60 MPH, the messages "Service Charging System" and "Service Diesel Emissions System" were displayed, and suddenly the power steering and power brakes malfunctioned, causing the contact to almost lose control of the vehicle. The cause of the failure was not yet determined. The local dealer was notified of the failure. The manufacturer was not yet contacted. The failure mileage was 79,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11687786September 17, 2025
ELECTRICAL SYSTEM, POWER TRAIN
Truck will down shift and transmission will slam, super hard. feels like i hit something. almost causing accident. dealership refuses to service my truck or even take a look at the transmission because "its not broken yet" in their words " it needs to fail before they can service it or even look at it, because they wont get paid." I have expressed my concerns about this safety issue and at this point they are being negligent. My truck is a 2023 gmc sierra 1500 with 3.0 duramax . still under warranty with only 35k miles.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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