GMC Sierra Complaints

15,732 consumer complaints on file.

#11753160July 27, 2026
SERVICE BRAKES
My 2025 Sierra 2500HD repeatedly displays “Trailer Brakes Disabled—Service Required” with a lithium- and solar-equipped trailer. The truck passes the EL-52641 simulator, but the failure occurs intermittently while towing and resets after Park or reconnecting the trailer. This closely matches the higher-trailer-battery-voltage/backfeed condition described in N232414840. Please open a TAC case and determine whether my 2025 has the revised Trailer Brake Power Module or whether GM engineering authorizes module replacement.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752901July 26, 2026
FUEL/PROPULSION SYSTEM
While driving enroute to a concert in [XXX]., in the passing lane on [XXX] around [XXX] & just before exit 22(mile marker 21) during rush hour on 7-23 at 5.09pm, my truck abruptly lost power and shut off! It would not start, I could not engage "N" from "P" to attempt to push my truck to the far left side of the highway. This was a "VERY DANGEROUS" situation as I could have been rear ended or much worse! I immediately called SOS/ON STAR for assistance. In the meantime, a police officer and state troopers showed up to divert the traffic around my truck. Eventually, a "HERO" vehicle showed up and at the direction of the police, my truck was "DRAGGED" from the passing lane to the emergency lane. As for getting a tow truck, 1 finally showed up after 5+ hours. I found out the you all have a contract with "AAA", which is the worse when it comes to getting any assistance. I was towed back to [XXX] to South Town GMC dealership & arrived at 11.25pm. It was only the next morning that I received an email from OnStar dated 7-23 at 5.07pm, with an "Advance Diagnostics" advising of a critical issue with the engine & transmission. The code was: P129F, which is the fuel pump and/or module. My truck now sits at the dealership with a dead battery, waiting for them to address. I have heard that there are issues and recalls in certain vehicles with this similar issue. I do have "extended warranty" protection thru Ally that I bought. However, the shock is finding out that the only way to get it into "N" is a special dealer tool that goes into the transmission under my truck! Are you SERIOUS??????? To have no ability to put my truck into "N" is not only unacceptable, but extremely dangerous. Especially with what happened to me & my family. At this point, I am at the mercy of my dealership to find the time to address this issue. Until then, I have no transportation & very upset with the stress of all that happened! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752905July 26, 2026
ENGINE
The engine (6.2L V8) in my 2024 GMC Sierra 1500 AT4 failed at approximately 40,750 miles. I began hearing a ticking noise coming from the engine, and the dealership subsequently diagnosed the cause as damaged bearings that in turn damaged the crankshaft, requiring a full engine replacement. Notably, this vehicle was not included in the related recall covering this engine defect, despite exhibiting the same failure. The original failed engine may be available for inspection upon request but I would need to confirm with the dealership whether it was retained or already returned to GM under warranty. This defect creates a serious safety risk because a damaged crankshaft and bearings can cause the engine to lose power or shut off without warning while driving. An unexpected loss of engine power at highway speed or in traffic could result in loss of vehicle control, reduced ability to accelerate out of a hazard, and increased risk of a collision to myself and to other drivers on the road. The failure gave no advance warning, so there was no opportunity to pull over safely before the issue became apparent. The fact that this failure occurred outside the scope of the existing recall suggests other vehicles with the same defect may be similarly at risk without notice. The dealership diagnosed damaged bearings and a damaged crankshaft as the cause of the ticking noise and performed a full engine replacement under warranty, confirming the failure. The dealership diagnosed the failure and performed the repair; I do not have direct confirmation of whether GM's engineering or warranty division conducted a separate inspection of the failed components beyond the dealer-level diagnosis. No warning lights or messages appeared on the dashboard at any point. The only symptom prior to failure was a ticking sound from the engine which I noticed shortly before the engine required replacement. I was not provided any electronic warning that would have alerted me.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752774July 25, 2026
POWER TRAIN
While towing my trailer the vehicle intermittently slams gears and will hesitate the back tires momentarily to the point of screeching. This has led to close calls being nearly rear ended and having to pull over. This started out as a hard slam while trailering on the highway and has progressively gotten worse. Had into dealership twice to multiple times to try and figure out the issue but it’s not throwing any codes and they can’t get it to duplicate the issues. Nothing can be replaced due to no codes even though they think the valve body is going bad. Leaving the vehicle as a ticking time bomb for failure which could result potentially in a catastrophic incident. Only had the vehicle for one year now has 37k miles on it and have had the ecm, full wiring harness, and multiple sensors replaced already for a different problem early this year that had the truck in the shop for a month.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752669July 24, 2026
ELECTRICAL SYSTEM
The contact called on behalf of an insurer who owns a 2026 GMC Sierra 2500. The contact stated that 15 minutes after the vehicle was parked and turned off, a neighbor informed the owner that the vehicle had caught on fire. The owner and the neighbor extinguished the fire using water hoses. The contact stated that the fire originated under the rear passenger’s side seat and was caused by an overheating amplifier that had short-circuited. No warning light was illuminated. The Fire Department responded to the scene and filed a report. There was no Police report filed. There was no injury or property damage. The vehicle remained parked, and the owner intended to return the vehicle to the dealer. The owner was provided a loaner vehicle. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure, and a case was opened, but no assistance was provided. The failure mileage was approximately 9,000.
Crash:
No
Fire:
Yes
Injuries:
0
Deaths:
0
#11752674July 24, 2026
SERVICE BRAKES, STEERING, SUSPENSION
Vehicle: 2021 GMC Sierra SLT | VIN: [XXX] Dealership: Carl Black GMC Roswell, GA (11225 Alpharetta Hwy, 30076) | Invoice #[XXX] | Service Date: [XXX] Paragraph 1 – Suspension Hazard: Dealership diagnosed a worn left upper ball joint (popping sound on left turns) and installed Rough Country aftermarket upper control arms on my stock-height Sierra SLT. These arms are designed for lifted suspension and alter factory caster/camber geometry, placing extreme stress on ball joints. This can cause sudden ball joint separation, wheel collapse, and total loss of steering control at speed. The dealership admitted on the invoice they "could not find branding" on original parts and chose non-OEM lift components without my consent or any safety disclosure. Paragraph 2 – Brake Failure & No Safety Warning: The same service included a full front/rear brake job (pads + resurfaced rotors) using their certified technicians and parts. After pickup, the brakes failed to operate properly. When I returned, the service manager refused to correct their own workmanship and instead quoted $1,900 to repair the very brakes they just serviced. Most critically, at vehicle pickup they issued no written or verbal safety warning—no "do not drive" instruction—despite the brakes being knowingly compromised, endangering me and the public. Paragraph 3 – Requested Action: The service manager was unprofessional, condescending, and refused accountability. I request an immediate NHTSA investigation into Carl Black GMC's unauthorized use of lift-kit suspension parts on stock vehicles, failure to warranty their own brake service, and reckless omission of safety warnings at delivery. This dealership pattern poses an imminent public risk. Please escalate. 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
#11752717July 24, 2026
ELECTRICAL SYSTEM, VEHICLE SPEED CONTROL
6 month old, 9,000 miles 2026 Sierra 1500 with Duramax 3 liter suffered an engine control module failure 4 hours into a 12.5 hour drive home from family vacation. First a transmission service warning flashed, then an emissions system failure with a forced speed reduction warning. This happened with two children and a dog in the vehicle. OnStar did diagnotics and said I had to see a dealer. Fortunately one was nearby and they determined the engine control module needed to be replaced--but i was 8.5 hours' drive from home with kids and dog and would have had to stay for 2-4 days awaiting parts and repair. I traded the truck at the dealer for a new vehicle and drove that home. This was a major safety concern traveling with children and a dog on a nearly 100 degree day. And it was a brand new vehicle.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752322July 23, 2026
TIRES
The contact owns a 2022 GMC Sierra 3500 equipped with Goodyear Tires, Tire Line: Wrangler Trailrunner AT, Tire Size: LT275/65/R20, DOT: (N/A). The contact stated that while hauling a camper and driving approximately 45 MPH and making a left turn, the driver's side rear tire had a blowout and the tread detached from the tire. During the failure, the camper swayed to the left. The contact was able to regain control of the vehicle and decelerated until the contact was able to stop the vehicle. While on the side of the road, the contact replaced the tire with the spare tire. The dealer was contacted and notified of the failure. The cause of the failure was not determined. The manufacturer was not made aware of the failure. The failure mileage was 27,666.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752346July 23, 2026
POWER TRAIN
While towing my fifth-wheel trailer, I was descending a hill (I had my tow/haul switch engaged) when I noticed an issue with my vehicle. Upon reaching the bottom of the hill and beginning to decelerate, when applying gas to continue up the hill the vehicle shuddered noticeably. A warning light briefly illuminated on the dashboard and then turned off shortly afterward. Although the warning light went away, the vehicle continued to exhibit a slight vibration, particularly between approximately 25 and 50 mph. I was able to drive the vehicle home safely and subsequently brought it to the dealership for inspection. The dealership performed a diagnostic scan and retrieved fault codes. Based on their findings, they have determined that the transmission requires replacement and are proceeding with that repair. They also found a different fluid in the transmission fluid, they skipped the testing and got permission to change out the transmission
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752365July 23, 2026
ENGINE
Complete engine failure while driving on a highway. While cruise was set, the truck emitted a sound and sensation like we had run over something on the highway. Within a few minutes the engine started ticking. The cruise was disengaged which thru the truck into neutral. No dashboard sensors were illuminated. We were able to get off the highway but the truck would not restart. Truck was towed to nearest dealer who has confirmed engine failure.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752417July 23, 2026
ENGINE
The contact owns a 2019 GMC Sierra 1500. The contact stated that upon starting the vehicle, the engine seized. There was no warning light illuminated. The vehicle was towed to a local dealer to be diagnosed. The contact stated was informed that the engine failure was caused by rod bearing failure. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 115,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752469July 23, 2026
POWER TRAIN
When going up my 5% grade driveway the truck has slammed into “park” while moving two times. The car turns off as it slams into park and a “ service transmission” warning is on the dash. It leaves small skid marks from doing this while moving. It has 1790 miles on it. Dealer has had it a week and says they cannot duplicate the issue. Google search seems to indicate many trucks have had the same issues going up an incline.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11751989July 22, 2026
ENGINE
Driving down the interstate at 70 miles per hour, started losing power, engine light came on. Engine started making a loud banging noise as I pulled onto an exit.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752068July 22, 2026
POWER TRAIN
Engine light came on while driving and a message on dashboard said Service Transmission Now.Unable To Shift Soon. Took to dealer and they said it was the park position switch 1circuit high. Had to order part but not knowing how long to get it. Truck only has 12468 miles. Luckily I got it to the dealer ASAP. IF I were on the highway or a remote road, I feel that a serious accident would have happened. Having an electronic controlled console shifter not being able to get the truck to shift gears to slow down or stop is a real safety issue. Extended warranty does not cover anything like this. Please look into this. Thank you
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752078July 22, 2026
SERVICE BRAKES
My vehicle a 2016 GMC Sierra 1500 upon lower idle speeds loses vacuum pressure. As the vacuum level drops the brake assist decreases, increasing the braking effort, extending the distance required to stop the vehicle, which increases the risk of a crash. I have had a warning light come on advising to service the brake assist system. I took my truck to a local mechanic who confirmed the codes and learned that there had been a GM recall associated with this failure at one time, with GM recall # N192268490. There is also NHTSA recall bulletin 19V645000 regarding this matter as well. Upon contacting some local GM dealers in the area, I was informed that my VIN was not listed as one of the vehicles affected by this recall, so a recall notice was never sent regarding my vehicle. I was also told that I just fell outside their 10-year window regarding this matter and that they would not repair this safety issue under warranty. I called the GM customer service who could not explain why the VIN associated to my truck was not listed and they said I should contact NHTSA and start a claim for potential reimbursement in the future after repairs are made. I feel that this is an unnecessary step as I believe GM should honor their product and repair an obvious safety issue with the truck, especially since they knew this was an issue in thousands of their trucks where it was not my fault my vehicles VIN was not included as a potential recall issue, but I am following their suggestion
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752087July 22, 2026
POWER TRAIN, ENGINE
On June 25, 2026, at approximately 84,000 miles, while traveling approximately 60-65 mph on Highway 121 in a posted 65 mph zone, driving my 2021 GMC Sierra 1500 AT4 equipped with the 6.2L L87 engine, multiple warning messages suddenly appeared, including “Check ESC,” “Check Parking Brake,” “Check Brakes,” and “Check Engine.” The engine began operating abnormally. I drove directly to Sewell GMC because I was concerned that the engine could fail or the vehicle could lose propulsion while in traffic. There was no crash, fire, or injury. Sewell GMC inspected the vehicle and confirmed catastrophic internal engine damage. The technician found metal debris in the engine oil and oil pan, damaged internal bearings, and camshaft/lifter damage. Sewell advised that the complete engine must be replaced. The vehicle remains at the dealership, has not yet been repaired, and the engine and failed components should be available for inspection. Before this incident, I had not experienced warning lights or symptoms indicating that an imminent catastrophic engine failure would occur. GM and the dealership advised that my VIN is not included in the current L87 engine recall because the engine was built in 2020. However, the diagnosed bearing damage, metal contamination, and catastrophic engine failure appear similar to the engine failures addressed by that recall. I am reporting this because an unexpected internal engine failure while driving creates a serious risk of loss of propulsion and a collision.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752098July 22, 2026
STRUCTURE, VISIBILITY
The contact owns a 2022 GMC Sierra 3500. The contact stated that the rear windshield frame was cracked, which allowed water to leak into the vehicle. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure. The failure mileage was approximately 29,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11752275July 22, 2026
ELECTRICAL SYSTEM, ENGINE
On 07/10/2026 at approximately 1:10 a.m., the parked and unoccupied vehicle caught fire while turned off. The vehicle had not been driven for several hours. A neighbor was awakened by the horn/alarm and popping noises, observed fire near the passenger-side cab/engine area, and called 911. The fire rapidly spread throughout the cab, engine compartment, rocker-panel areas, wheel wells, and truck bed, creating an explosion hazard and threatening a nearby occupied residence and garage. The fire department extinguished the blaze, but the vehicle was completely destroyed. Before the fire, the vehicle had experienced recurring coolant warnings, a DEF-system warning, and delayed starting associated with the main battery. No smoke, fuel odor, intentional ignition source, charging device, or known external fire source was present before the incident. Weather was calm. The exact failed component and cause remain UNKNOWN. A firefighter stated that the apparent fire origin was near the passenger side of the vehicle. The remains are available for inspection, subject to coordination with the vehicle owner and insurer. The incident has been reported to the fire department, insurer, manufacturer, and NHTSA.
Crash:
No
Fire:
Yes
Injuries:
0
Deaths:
0
#11752276July 22, 2026
ENGINE, FUEL/PROPULSION SYSTEM, POWER TRAIN
I was driving on the highway when the vehicle started to make clinking noises. The vehicle started to lose power as I accelerated it would feel like something was pulling me in the opposite direction and the knocking noise would get louder. Ultimately, I had the vehicle towed to a dealership. This vehicle passed the L87 recall not too long ago, and the vehicle is barely used.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11751712July 21, 2026
UNKNOWN OR OTHER, ENGINE
I bought the truck with 2 miles , shut off on me within 1,300 miles wouldn’t turn on , supposedly it was a bad fuse that was burned out , Second time it shut off on me again , all my sensors were going off and on and truck wouldn’t turn back on , they told me they couldn’t figure out the problem evaczue they had disconnected the battery and it erased all the codes 3rd time , they changed my oil and they forgot to torque the screw back correctly and all the oil spilled and cost my engine to lock up and mess up , they replaced the motor with a new one 4th time , supposedly it needs a replacement for a catalytic converter which is being replaced now as we speak or sometime this week
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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