GMC Sierra Complaints
15,732 consumer complaints on file.
- #11710984January 14, 2026STRUCTURE:BODY, ELECTRICAL SYSTEM
Setting in a parking lot and the tailgate fell open and hit another car. The tailgate was closed and has fell open 3 more times while the vehicle is in park and one time it was powered off.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11711022January 14, 2026ENGINE, UNKNOWN OR OTHER
My 2020 gmc sierra has had poor gas mileage problems i have taken it to gm a few times with them not able to dind anything wrong through diagnostic. A couple years later my horrible gas mileage came back and service ecs and stabilitrack message came back on and disappeared. I spoke to another shop and they advised me its the dfm lifter issues that everyone has been talking about. So the shop performed the well know fix and has fix the issue. A month after now the valve body gave me a p2817 code showing that the solenoid is stuck in the off and was also advised that this is a know issue being addressed. Currently the truck is in the shop. When is enough enough with all the issues across the nation whwn is gm going to make it right
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11711030January 14, 2026ELECTRICAL SYSTEM
About 2-3 months ago I had a battery swell up and start smoking and making an awful smell in my truck. I took it to dealership and was informed that I needed a new battery and it was not covered under bumper to bumper warranty or my extended warranty which I thought was ludicrous. The truck is 18 months old. It does have 50,000 miles but I have yet to see one that isn’t at least prorated for five years. So fast forward to today and the other battery starts doing the same thing except this time my lights are going crazy. Brights on and off and on and off. I get back to my camp and the battery and wiring is smoking like crazy. I towed it to the shop. It’s been in there two weeks and the only thing they tell me now is that I need 2 new batteries and that’s all they can do until I agree to pay for the other one that isn’t under warranty (because I already paid 300 to change 1st one it’s under warranty for 5 years). So I told them to do it. It’s been there two weeks and not a damn thing has been done. Not even installed a new battery. I know because I went yesterday and they couldn’t open my tailgate to get my tools out. Probably the last GMC I purchase.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710755January 13, 2026ENGINE, POWER TRAIN
2022 GMC AT4 w/ 6.2L V8 was my retirement gift to myself at a cost of $70k. I have had 2(two) engine failures! Of course they failed in the middle of rush hour traffic when no one wants to be kind. Since the wheels will NOT rotate once the failure has occurred, I was stuck in middle of traffic for 2 hours awaiting a tow truck. Not even 3k miles after the 2nd engine failure I was told by the dealership that I now need a transmission replacement. As a loyal GM customer, GM has to do better.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710769January 13, 2026ENGINE
Complete engine failure, at 57,000 miles, was driving approximately 75 mph on the I-15 in Utah outside of St. George, and the left lane, engine turned off, was able to pull safely in a shoulder in a canyon with my family, my wife, my kids [XXX] and [XXX] old. Vehicle was towed that evening at 7 PM to the dealership, where it was diagnosed with completed engine failure. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710568January 13, 2026FORWARD COLLISION AVOIDANCE: WARNINGS, BACK OVER PREVENTION: WARNINGS, LANE DEPARTURE: ASSIST
On Christmas Day 2025 my Tailgate flies open on its own and I see my cargo flying out and a piece of it bounced off my taillight passenger side braking the taillight and then when attempting to pull over my lane departing feature try’s to correct its self and I hit the median luckily at slower than I was going but enough to make a decent dent on front bumper
- Crash:
- Yes
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710304January 12, 2026ENGINE
With approximately 5,200 miles on my new vehicle, received an error message on the dash while driving on 1/8/2026 that read “Reduced acceleration; Drive with care”. I immediately took the vehicle to a local GM dealership and was informed on 1/9/2026 that due to a faulty thrust bearing (covered under the non-mandatory technical service bulletin 25-NA-307), the entire engine sustained a catastrophic failure and that the engine “tanked itself” and “grenaded itself”. Driving with the reduced acceleration mode active is beyond frightening as it’s very difficult to navigate traffic intersections in time to avoid oncoming traffic. It was also noted that it other cases where this faulty part causes the engine to totally fail, the vehicle becomes unusable at that point. I was informed that a replacement motor is not expected from General Motors for at least 2-3 months as this is becoming a more prevalent issue with certain 2025 Sierra’s with the 3.0 Duramax diesel motor.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710305January 12, 2026SERVICE BRAKES
While traveling at low speeds in parking lots and in the operation of parking, my 2016 GMC Sierra 1500 gets a hard brake pedal that goes to the floor but I have no brakes. I almost hit a person in a local grocery store parking lot, at the bank driving up to the ATM, and I almost lost my truck over a bank because the brakes failed. This has happened multiple times at low speeds but it is getting more consistent recently. It has endangered myself and others. It is only a matter of time until damage occurs or someone gets hurt.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710403January 12, 2026POWER TRAIN
Summary of Issue On [XXX], my family and I departed Kansas City, Missouri, for a camping trip to Great Smoky Mountains National Park (Cades Cove), Tennessee, approximately 800 miles away. We were towing a 2020 Forest River Salem FSX/RTX travel trailer, estimated at approximately 6,000 pounds loaded, using a Reese weight distribution hitch with integrated sway control. This load was well below the rated towing capacity of the vehicle. On [XXX], while driving without the trailer attached, the vehicle displayed multiple warnings including “Reduced Engine Power” and a transmission system alert. I immediately pulled over, shut the vehicle off, and restarted it. The warnings persisted. I cautiously drove approximately five miles to Twin City GMC, where the vehicle was diagnosed with a failed transmission valve body. Dealer and Manufacturer Response The service manager at Twin City GMC informed me that the required valve body was on national backorder, with multiple vehicles ahead of mine, and that wait times had reached up to three months. To confirm, I contacted Molle Chevrolet (Blue Springs, MO) and Randy Curnow GMC (Kansas City, KS). Both dealerships independently confirmed that this was a known and recurring issue, and that extended backorders for the valve body were common. I was informed that GMC could provide a daily rental allowance, but the rental vehicle would not permit towing. With my family, three dogs, and travel trailer stranded 800 miles from home, this option was not viable. As a result, I was effectively forced to trade in my truck and purchase a replacement vehicle to safely return home. Manufacturer Awareness and Complaint History GMC has demonstrated awareness of this issue through service bulletins, widespread owner reports, and media documentation addressing transmission valve body failures and parts shortages. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710215January 11, 2026ELECTRICAL SYSTEM, ENGINE, FUEL/PROPULSION SYSTEM
2026 Sierra 1500 AT4 with 3.0L Duramax Diesel. Three major issues. 1. 2960 miles, thrust bearing failure caused low oil pressure and internal damage. Vehicle needs complete engine replacement. The truck is still at the dealer with no ETA on engine arrival and replacement. 2. Vehicle has severe electrical issues. battery replaced on second day of ownership due to over charge and smoking. The truck would randomly lose the ability to produce sound through infotainment system on start. This includes warning sounds and audible turn signal sound. Dealer said it’s caused by faulty Amp which was replaced. 3. The truck shut off (full system shutdown) and the transmission failed over to neutral while driving on the highway and failed to restart. Barely restarted on second attempt. Dealer has no idea why it is doing it. However the vehicle was throwing multiple code related to transmission module failure, brake module failure, transmission module failure, etc.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710239January 11, 2026ENGINE
While driving vehicle at highway speeds the vehicle shut down without any warning
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710058January 10, 2026SUSPENSION, UNKNOWN OR OTHER
Had a minor wreck was to be two weeks to then it had to have a new frame they said it coun't be repair if a minor wreck can do this much damage there is a problem with subpar frames that any sudden stops or turns
- Crash:
- Yes
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710140January 10, 2026LANE DEPARTURE: WARNING, LANE DEPARTURE: ASSIST, FORWARD COLLISION AVOIDANCE: WARNINGS
The front camera stopped working, causing the safety systems to shut off. Codes U026A & U0078 "no communication failure". The camera was ordered and replaced.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710151January 10, 2026ENGINE
The service engine light came on while driving on the highway. We took it to a GMC dealership and they scanned to determine a short in the oil pressure sensor. This was replaced then during the final check they found metal in the oil. The warranty company made them tear the engine apart where they found multiple area where the metal was worn down including the gaskets, rings, and cylinders. The warranty company continues to fight us to cover the whole invoice.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710153January 10, 2026SERVICE BRAKES
Left rear parking brake actuator malfunction. The truck would brake unexpectedly. The brake would not completely release at times. Took it to the dealer on June 6, 2024 and they replaced the rear rotors and pads. I asked them if the parking brake actuator was faulty and may have caused the premature wear. They laughed and said no, it wasn't possible. On Aug 7, 2024 I returned the truck to the dealer with the fault codes C1114 & C060B caused by a failure of the parking brake actuator. It was impossible to use the emergency brakes when the codes were present. For several months after the repair, brake faults would appear and disappear randomly. Took it to the dealer, and they found nothing wrong. Electric-actuated emergency brakes should be illegal.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11710159January 10, 2026POWER TRAIN
Unexpected rear wheel lock-up at 29000 miles. While engine braking from highway speed onto an off-ramp at approximately 50 mph, the rear wheels unexpectedly locked up. Due to prior rear brake actuator issues, I suspected the emergency brake had activated without my input. It was only momentary, and no fault codes or warnings were displayed. It happened again under the same circumstances two months later, with no fault codes. On May 9, 2025, the check engine light came on, and I scheduled service. The dealer addressed a recall regarding the transmission by installing software. In August 2025, I received a letter from GM regarding recall N242454440 for excessive wear in the transmission control valve, which was causing rear-wheel lockup. On October 31, 2025, while towing a small enclosed trailer at 70 mph on the highway with cruise control engaged, the truck suddenly decelerated, and I was nearly rear-ended by a semi-truck (no brake lights to warn them). The truck would not go over 50 mph unless I was going downhill. The transmission would not shift into higher gears. I returned it to the dealer, who checked the computer and found no record of the incident, so they said there was no problem. They informed me that the new software was designed to limit the truck's speed if a potential lockup was detected. This recall did not fix the transmission problem or the safety issue. It was simply a way to avoid costly repairs. There is a problem with the physical transmission valve that, for me, resulted in an extremely dangerous situation. The NHTSA needs to take this issue seriously and require GM to replace the prematurely worn valves in the affected vehicles.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11709888January 9, 2026ENGINE
The contact owns a 2019 GMC Sierra 1500. The contact stated that while driving 75 MPH, the vehicle failed to accelerate as intended while depressing the accelerator pedal. There was an abnormal sound coming from the engine. No warning lights were illuminated. The contact stated that on a separate occasion, while driving at an undisclosed speed, blue and white smoke was coming from under the hood. The contact pulled over to the side of the road, and the smoke ceased. The contact opened the hood and inspected the engine. The contact restarted the vehicle, and the smoke started coming from under the hood again. The messages "Parking Brake Service Required”, “Reduced Steering Assist”, “Proceed with Caution" were displayed, and the check engine warning light was illuminated. The contact stated that while driving and coming to a stop, the engine jerked abnormally. The vehicle was taken to an independent mechanic, where it was diagnosed with oil intrusion into the spark plugs with a misfire in cylinder #6, and the piston rings were fractured, and there were scratches on the cylinder walls. The vehicle was not repaired. The contact stated that the failure persisted. The manufacturer was made aware of the issue. The contact was referred to the dealer for assistance. However, the contact was concerned about the damage to the engine and feared driving the vehicle. The vehicle was not taken to the dealer. The failure mileage was 71,799.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11709922January 9, 2026POWER TRAIN
Just after merging from I-65 North to 264 East at 65 mph in Louisville KY on November 14th, the display indicated to "press start" and the engine stalled. I was only able to get the vehicle about 3 inches off of the left side of the yellow line before running out of inertia. I was stuck there for 2 hours while waiting for a tow truck. The first truck could not lift my vehicle because with the engine off, the electric shifter would not move out of park. A second tow truck was called with dolly's and then a 3rd tow truck was required to block traffic. During this 2 hour period several cars swerved left of the yellow line and I was in fear for my life. The traffic was so heavy that I was trapped between the concrete median wall and the left lane. I called 911 to ask for a safety vehicle to shield me from traffic, but they never arrived as promised.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11709924January 9, 2026POWER TRAIN
The contact owns a 2020 GMC Sierra 1500. The contact stated that while his wife was driving at an undisclosed speed, the vehicle jerked violently. The driver stated that the vehicle failed to respond as intended while depressing the accelerator or brake pedal. The check engine warning light was illuminated. The driver was able to pull over to the side of the road. The vehicle stopped jerking while driving but failed to exceed 30 MPH. The driver pulled into a parking lot and parked the vehicle. The contact was made aware of the failure and went to the parking lot. The vehicle was restarted and jerked abnormally. Additionally, while shifted into reverse(R), the vehicle failed to function as intended. The vehicle was taken to the dealer, where it was diagnosed, and two DTC were retrieved for unknown transmission software failure, and it was determined an unknown part in the transmission had failed. The dealer informed the contact that an unstated recall was closed. The vehicle remained at the dealer unrepaired. The manufacturer was made aware of the failure, a claim was filed, and the contact was informed that the recall was closed. The failure mileage was approximately 146,000.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11709935January 9, 2026ENGINE
MY 2020 GMC SIERRA DENALI EXPERIENCED A COMPLETE ENGINE FAILURE in June of 2024. Dealer repair was in excess of $7,700.00. They stated they knew this was going to happen at about the 70,000 mile mark as they have fixed many in that same time. Repair resulted in rod replacement and cam shaft damage and replacement.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0