GMC Sierra Complaints

15,732 consumer complaints on file.

#11749030July 8, 2026
POWER TRAIN, SERVICE BRAKES, HYDRAULIC
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11749070July 8, 2026
ENGINE AND ENGINE COOLING
The contact owns a 2020 GMC Sierra 1500. The contact stated that while accelerating from a complete stop on several occasions, an abnormal clicking sound was heard from the engine compartment. The vehicle was taken to the dealer, where it was diagnosed with a failed fan belt pulley. The vehicle was not repaired. Additionally, while parked on one occasion, an abnormal clicking sound and a loud bang were heard from the engine compartment, and the vehicle stalled. The contact attempted to restart the vehicle, but it failed to turn over. The vehicle was taken to the dealer, where a failed valve spring was diagnosed. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 75,127.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11749076July 8, 2026
POWER TRAIN
My car suffered a catastrophic engine failure, metal schards were found in the oil filter and was left out of the 2021 recall 25V274. The in service date of vehicle is March 13, 2021. The car was 83 days out of warranty when the engine failed. The truck has 47,000 miles on it. They are now trying to charge us, barter with us. They have gone from $2800 for repair, negotiated down to $100 to sign this off as a good will repair stripping us of lemon law rights and future recall remedies. Car is currently sitting at the dealership.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11749086July 8, 2026
POWER TRAIN
The contact owns a 2022 GMC Sierra 1500. The contact stated that while merging onto the interstate at approximately 65 MPH, the rear wheels unexpectedly locked up without warning. The contact stated that the rear wheels remained locked for approximately half a second, causing a sudden reduction in speed and requiring the contact to pull over to the shoulder of the road. The vehicle was driven to a relative's residence and was then towed to a dealer. The dealer had not diagnosed the failure, and no repairs had been performed. The manufacturer was notified of the failure, and the contact was advised that there would be a follow-up. The failure mileage was approximately 32,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11749108July 8, 2026
STRUCTURE:BODY
My 2026 GMC Sierra has an oil-canned roof from a touchless car wash because the sheet metal lacks structural rigidity. This caused the roof to buckle and caused a permanent fold in the roof of the truck. There is already documented issues for this exact problem on the newer GMC Canyons and Chevrolet Colorado mid-sized trucks. Bulletin for reference NHTSA Official TSB #23-NA-209 PDF. I leased the vehicle on 6/19/2026 and this happened on approximately 7/7/2026. The vehicle only has 1,480 miles on it as of this date.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11749124July 8, 2026
ENGINE
The contact owns a 2021 GMC Sierra 1500. The contact stated that while turning the ignition on, the "Service Parking Brake" message was displayed, and the check engine warning light illuminated. Additionally, the engine ran rough. The vehicle was taken to the dealer, where it was diagnosed that the engine lifters needed to be replaced; however, the dealer could not diagnose if there was further engine damage until the lifter repair was completed. The manufacturer was made aware of the failure. The failure mileage was approximately 72,530.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11748693July 7, 2026
ENGINE, POWER TRAIN, VEHICLE SPEED CONTROL
I was driving my family on the highway and my truck completely shut down. The screen flashed a warning and it slowly started decelerating. Thankfully I was able to make it to the shoulder of the road safely. Engine failure was a known safety issue with my model of truck, but I completed the L87 Engine Loss of Propulsion safety recall testing on 9/18/2025 and was assured my engine passed the testing and was not at risk for engine failure.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11748736July 7, 2026
STRUCTURE:BODY
On July 3,2026 I was driving my 2022 GMC Sierra 1500 on the highway at a speed of 70mph when the front chrome deflector flew off my vehicle. It tore paint off the hood, and also cracked my windshield. I searched online and noticed this had a safety recall for this issue. I see the recall was done in January 2026, AND has failed completely. I still have the service records of previous repair. GM is giving me issues on finding a remedy to fix this.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11748748July 7, 2026
FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
The adaptive cruise control has twice unexpectedly applied the brakes with sufficient force to result in a minor whiplash situation of a sore neck. Both times were driving on a two-lane highway traveling between 65-70 mph (cruise control was set a 68 mph) with no vehicles in the lane in front of me. The adaptive cruise control appeared to interpret oncoming traffic as a vehicle in front of me and aggressively applied the brakes, rapidly dropping my speed from 68 mph to the 35 mph range. Brakes were applied with such force that my neck was sore for about two weeks after each incident. My vehicle also has automatic emergency braking (AEB), but I don't believe this system was activated as the warning lamp on the dash and the audible alert was not activated in either situation. These incidents are related to the adaptive cruise control feature, not the AEB system. The dealership has not had an opportunity to inspect the vehicle yet, or any other agencies. In both incidents, no warning lamps or audible alerts were activated.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11748763July 7, 2026
ENGINE
What component or system failed or malfunctioned, and is it available for inspection upon request? The engine/powertrain failed. The vehicle is a 2025 GMC Sierra 1500 equipped with the 6.2L V8 engine. The engine developed a severe knocking noise and loss of power at approximately 5,545 miles. The vehicle was taken to the GM dealership, where an engine replacement was approved. The failed engine/component may be available for inspection through the dealership or GM, depending on whether it has already been removed or returned to the manufacturer. How was your safety or the safety of others put at risk? The engine failure created a safety concern because the vehicle experienced reduced power/loss of propulsion while being operated. This could have put me and other drivers at risk because a sudden loss of engine power can make it difficult to safely maintain speed, merge, tow, or move the vehicle out of traffic. The issue occurred at very low mileage and without enough warning to prevent the failure. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. The problem was confirmed by a GM dealership. The dealer diagnosed the engine failure and GM approved an engine replacement under warranty. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? The vehicle was inspected by the GM dealership. GM was involved in approving the engine replacement under warranty. To my knowledge, the vehicle has not been inspected by police or insurance representatives. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? Prior to the failure, the vehicle developed a severe engine knocking noise and reduced power/lack of power. These symptoms appeared shortly before the engine failure at approximately 5,545 miles. I do not recall any specific warning lamps or messages before the failure, unless the dealership records
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11748774July 7, 2026
ENGINE
I was driving at normal highway speed. I exited the highway and started to deceleration for an upcoming traffic light. The engine started making a lot of noise. The 6.2L engine has 31k miles on it. Oil changes have been completed at the dealership where I purchased the sierra Denali. I called the dealership and the service writer could hear the engine noise. He asked if I could get it to the dealership which was about 15 miles away. I tried but the truck stopped about 7 miles from the dealership. They told me to call the onstar service and get a tow. The dealership said it will take about six weeks to get a new engine. In the meantime I'm making payments on an eighty thousand dollar vehicle I can't use. Someone needs to hold GM accountable for the lack of urgency in getting this problem fixed!
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11748779July 7, 2026
ELECTRICAL SYSTEM, BACK OVER PREVENTION: WARNINGS, BACK OVER PREVENTION: REARVIEW SYSTEM BRAKING
No sound at different times. No way to reset issue. TSB issued May 14, 2026 for known issue. As of July 6, no estimate on repair. Blinkers make no sounds, Onstar can call but you cannot hear them. In event of accident, no communication.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11748812July 7, 2026
ELECTRICAL SYSTEM, ENGINE
I own a 2021 GMC Sierra AT4 3.0L Duramax (VIN [XXX]). The vehicle has codes P1098 (Coolant Control Valve Performance) and P129F which coincides with the first code. My dealer believes this is consistent with an Engine Coolant Control Valve failure. I understand Special Coverage XXX exists for this issue, but I've been told my VIN is not included. My truck has the exact engine, symptoms, and diagnostic codes addressed by Special Coverage N252508341, but my VIN is excluded. 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
#11748816July 7, 2026
ENGINE
The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the "Add oil to engine" message was displayed. The vehicle was driven to an AutoZone within two minutes and turned off. Upon inspection of the engine oil level, the contact observed that the dipstick was completely dry. The dealer was notified of the issue, and an appointment was scheduled for an oil consumption test. The vehicle was not yet diagnosed or repaired. The contact stated that the vehicle had been serviced for a routine oil change on April 21, 2026, at 53,590 miles. The contact related the failure to NHTSA Action Number: RQ26001(ENGINE). The manufacturer was not made aware of the failure. The failure mileage was approximately 56,802.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11748834July 7, 2026
ENGINE
I believe I had a lifter failure as I was traveling up SR 393. Safety issue as vehicle lost power. Vehicle is at dealership now and confirmed possible lifter collapse. No dashboard lights were on or any power issues prior.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11748839July 7, 2026
SERVICE BRAKES
When backing up, either on a hill or flat surface, the brakes fail to stop the vehicle. There is a pulsing sensation with the brakes due to failure of the vacuum. The brake pedal also becomes impossible to depress. No warning lights appear when this occurs.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11748895July 7, 2026
SERVICE BRAKES, ELECTRICAL SYSTEM, POWER TRAIN
On XXX, I was towing my camper to Copper Center, Alaska from Palmer, Alaska when my truck experienced a full transmission shut down which put the truck into "Reduced Power Mode". We descending down the road right next to Victory Bible Camp (64741 Victory Rd, Sutton-Alpine, Ak 99674) when the exhaust break turned off and the truck decreased power and the Check Engine Light illuminated. The Diagnostic that was produced by OnStar revealed 3 different codes. ( P0700 TCM, P0747 Pressure Control Solenoid A is stuck in the "ON" position, C116b faulty brake pad wear sensor.) I called GMC of Palmer and GMC OnStar advisor, both informed me that the truck needed to be towed. My safety concerns is this.... I had minimum cell phone signal and not a gas station or service station within MILES. I was on the side of the Alaska Highway 1 which is a major thoroughfare for traffic going to and from [XXX]. Thankfully there were a few kind folks that pulled over to offer assistance. My truck is a 2023 GMC Sierra 2500hd with only 26,262 Miles on it. I purchased this vehicle XXX. (It Still has the Temporary Tags on it.) If had been in a different part of Alaska when this transmission failed to function properly then we could be talking about a life or death situation. Especially, if my child was with me. I was hauling my camper that weighed ATMOST, 7,000 pounds. This is less than 40% of the trucks ability. I feel that this could put someone into a dire situation had they not had the experience with emergency situations like I have had. (Prior Military Service). I have also filed a complaint with GMC Motors. Case# XXX. 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
#11748920July 7, 2026
TIRES:TREAD/BELT
These tires are not safe for off-road to highway use. After transitioning to the highway from a gravel driveway, I noticed that rocks were stuck in the treads. A significant about of rocks became dislodged and start to contact my vehicles underbody steps. I feel as if this can create significant and costly problems for the vehicles that are following close or perhaps behind in any manner. Large rocks and what I would classify as mini boulders are often found lodged in the tread and don't come out till they are picked out or fly out.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11748443July 6, 2026
ELECTRICAL SYSTEM: INTEGRATED TRAILER BRAKE CONTROL
The contact owns a 2022 GMC Sierra 2500. The contact stated while driving at various speeds and pulling a 10,000 pounds trailer, the vehicle experienced an intermittent loss of trailer brakes. The message "Check Trailer Wiring" and another message pertaining to the trailer brake system were displayed. The vehicle was taken to the dealer, where the Trailer Brake Power Module (TBPM) was replaced; however, the failure persisted. The contact related the failure to GM Customer Satisfaction Program Number: N232414840 (Intermittent Loss of Trailer Brakes). The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance in adding the VIN to the Customer Satisfaction Program. The vehicle was not repaired. The failure mileage was approximately 110,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11748492July 6, 2026
ENGINE AND ENGINE COOLING
The contact owns a 2019 GMC Sierra 1500. The contact stated while driving at 55 MPH, the vehicle made an abnormal rumbling sound and stalled. All the warning lights illuminated. The vehicle was taken to a nearby independent mechanic, who determined that the engine lifter and cylinder had failed. The vehicle was not repaired. The local dealer was not contacted. The manufacturer was contacted and confirmed that there was no recall coverage. The manufacturer referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 98,003.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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