2021 GMC Sierra 1500 Complaints

ENGINE AND ENGINE COOLING — Filed 06/16/2026

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving 35 MPH, the engine was making an abnormal sound, and the vehicle failed to accelerate. The engine was popping and making cranking sounds, with several unknown warning lights illuminated. The vehicle was driven back to the residence with the issues. The contact referenced NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); as a possible cause for the failure; however, the VIN was not included in the recall. The vehicle was taken to a dealer where it was determined that there was metal fragments found in the oil filter, and recommended that the engine be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 50,000.

ENGINE — Filed 07/11/2026

I'm not sure if they've pulled it out yet. They said two weeks to get motor. Engine started shaking and then started knocking. Had wrecker take it to GMC dealer they said it needs an engine. It is a 2021 6.2 carbon pro 1500 Sierra AT4 it did not come up on recall list and I don't know why? it obviously the same problem.

ENGINE — Filed 07/11/2026

At 115,000 the coolant control valve has gone out. GM acknowledges this issues in 2020 model trucks. My truck is a 21 and displaying the same characteristics. A simple google search will show this is a known issue in 2021 vehicles as well. In 2020 model trucks GM has provided a special 150,000 mile warranty to replace this part. GM needs to step up and provide a proper warranty/recall for the affected 2021 models.

FUEL/PROPULSION SYSTEM — Filed 07/16/2026

P1098 code indicating stuck/ unresponsive engine coolant control valve. N252508341 exists for this part; however claim is my VIN is not covered under the bulletin or included on any standard warranty coverage. Part should last more than 150k miles, vehicle less than 90k. Less than 2 weeks ago suffered a complete EBPV failure that destroyed coolant and DEF lines, also not covered. No explanation for why my specific VIN (a 3.0L diesel in the supposedly covered MY) is excluded. Have been unable to find evidence of any applicable vehicles that were 'covered' under this bulletin. Fault forces an unexpected derate which can engage while accelerating, including while merging into freeway traffic. This is an obvious safety hazard. Engine check light illuminates approximately 30 to 60 seconds before derate limits top speed and throttle response. No messages to operator. Dealer has confirmed issue.

POWER TRAIN — Filed 06/01/2026

The 10 speed automatic transmission shakes and jumps between gears. The transmission also shakes and rumbles at cruising speeds. The diesel engine version of this truck is already recalled. My truck is a gas engine and should also be recalled. This is the same defective 10 speed transmission used in all GM vehicles and recalled in many. This vehicle needs to be recalled and fix before the wheels lock up and kill someone.

ENGINE — Filed 07/09/2026

I was driving and my check engine light came on a mile from my house. I drove home and the next morning, I started my truck. It was loud and pulsating like it wanted to stall out. I had it towed to a repair shop. They plugged into the truck and said it was giving code P0016. I had it towed to another place and that it is where it is sitting now. I also received a email from onstar saying "A critical issue with the engine and transmission system in your 2021 GMC sierra Crew Cab has been detected. P0016 was detected. I searched my VIN # and it says that there are no recalls on my truck. I do see that there was a silent recall on the engine that is in my truck.

ELECTRICAL SYSTEM,ENGINE,FUEL/PROPULSION SYSTEM — Filed 06/02/2026

I am submitting supplemental evidence regarding my 2021 GMC Sierra (VIN [XXX]) for Recall Query RQ26001, Campaign 25V-274. Despite multiple repair attempts, my vehicle remains unsafe and non-compliant with GM Service Bulletin N252494002. The recall remedy was performed deficiently. [XXX] Northeast Buick GMC installed a remanufactured short block instead of the required complete engine, reused the original seized-engine oil pan (which continues to leak), and failed to address critical electrical damage. Documentation proves they deleted Labor Operation 14BUZ (Engine Electrical) after their technician noted a blown mega fuse. A second dealer, Penske Chevrolet, subsequently deleted Labor Operation 77CVZ01 from my repair order, demonstrating a systemic pattern of ignoring recall-required repairs. Electrical damage has cascaded, resulting in a burnt fuse block and active faults P0615, P0617, P26E4, P26E6, U0623, and U0284. More critically, within 24 miles of my last service, the vehicle developed a new, severe safety failure: the "Service Brake Pad Monitor" system failed, accompanied by a red "Service System" dashboard alert and a noticeably spongy brake pedal. These brakes were recently serviced, yet this failure introduces a new risk of crash not present prior to the recall "remedy." GM Executive Resolution Case XXX has provided no resolution, reimbursement, or safety assurance, ignoring all deadlines since XXX. I possess extensive documentation, including service orders showing deleted labor operations and diagnostic logs. I request this update be integrated into the investigation of RQ26001, as the current remedy is demonstrably ineffective and has exacerbated safety hazards. The manufacturer’s refusal to remediate these issues, despite my compliance, leaves me with an unsafe vehicle and significant financial loss. I am prepared to provide all supporting records to substantiate this complaint. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

POWER TRAIN — Filed 12/31/1969

transmission shuddering, harsh or delayed shifting, and erratic gear changes. The truck jerks really bad during each shift of the ten speeds. A vibration or shudder typically occurring at speeds between 25-65 mph under light throttle. Also makes a bad noise every times it’s shifting. I have no lights on the dash and the gmc app tells me everything is fine when clearly it’s not . I see there’s a recall for my year and make but for some reason my vin doesn’t fall in the category

POWER TRAIN — Filed 06/04/2026

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.

ENGINE — Filed 07/01/2026

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.

ELECTRICAL SYSTEM,ENGINE — Filed 07/07/2026

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)

ENGINE — Filed 07/07/2026

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.

ENGINE — Filed 06/30/2026

Since purchase of my 1500 Sierra 6.2L on 10FEB2021, the vehicle has always appeared to burn an excessive amount of oil which is consistent with GM’s 6.2L engines and has created safety issues leading to sweeping recalls on this engine model from 2021-2024. I have been informed that the engine was consistently down 2+ qts of oil at every recommended oil change (approximately every 5000mi) although GM literature indicated that this level of consumption was usual in their 6.2L engine. In a JAN26 oil change at approximately 35,000mi I was told that my engine was down over 3qts of oil. On 17FEB2026 I took my vehicle into my Chevy/GMC Dealership to request an oil consumption test at ~35, 089mi. On 30JUN2026 I returned to the dealership for my 2000mi check-in, at ~37,800mi, and was informed that my vehicle had failed the consumption test. With over 600,000 vehicles recalled since 2024 in the 6.2L category, my vehicle/VIN has never been associated with a recall. Despite having minimal miles on this engine, I am now financially penalized for repairs because I had just exceeded the initial Powertrain Warranty and my extended warranty would not cover a pre-existing condition. GM’s 6.2L engines have pre-existing issues from the factory and represents a danger to consumers and the driving public because of these failures.

AIR BAGS,WHEELS — Filed 06/01/2025

• The airbag system failed to deploy during a collision that resulted in the total loss of the vehicle. Additionally, the vehicle was operating with a 17” spare tire (undersized compared to the standard 20” wheels), which may have contributed to the accident. The vehicle has been totaled and is currently in the possession of the insurance company, but may be available for inspection upon request. • Despite the severity of the collision, none of the airbags deployed, which could have resulted in serious injury if the circumstances were different. The use of an undersized 17” spare tire may have affected the vehicle’s stability, braking, or performance, contributing to the crash. • No. The vehicle was declared a total loss and has not been evaluated for defect reproduction by a dealer or service center. However, I am aware of related recalls and lawsuits regarding both improper spare tire sizing and airbag non-deployment in 2020–2021 GMC Sierra models. • The vehicle has been inspected by the insurance company during the total loss evaluation. A police report was also completed at the scene of the accident. To my knowledge, the manufacturer (GM) has not inspected the vehicle at this time. • No. There were no warning lights, messages, or symptoms prior to the crash. The vehicle gave no indication of any issue with the airbags or tire compatibility leading up to the accident. I was involved in an accident in my 2021 GMC Sierra. At the time, the vehicle was operating with a 17” spare tire installed, which I later discovered may be significantly undersized compared to the standard 20” wheels. During the crash, the impact was severe enough to total the vehicle, but none of the airbags deployed. Fortunately, there were no injuries, but I believe the non-deployment of the airbags represents a critical product safety defect. I’ve since learned that GM has recalled similar vehicles for incorrect spare tires, and that lawsuits have been filed regarding calibration issues.

STEERING,WHEELS — Filed 04/26/2025

I was driving approximately 25-30 mph coming over an overpass moving into the right hand lane when my truck right front end failed. The steering and brakes locked up for approximately 50’ until I hit the curb for the sidewalk and stopped. I safely exited the vehicle checked the left side of my truck for damage and didn’t find anything. I walked around the back of my truck and came to the passenger side where I found my right front wheel and tire completely broken away from both upper and lower control arms, the ball joint broke and failed as well as the brake line. If I was driving on the highway at 65-75 this catastrophic failure could have resulted in a fatal collision. The night before my [XXX] daughter and I returned from her outdoor Ed trip in Sausalito and we drove an hour home to Napa on [XXX] and [XXX] . I thank god this didn’t happen with her in the car on the highway. I had my truck towed to Jimmy Vasser Chevy in Napa so I can see if the extended warranty will cover the repairs since it was an obvious catastrophic failure of the whole right front end. It’s still sitting there. The extended warranty inspector came Friday to take pictures of the damage INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

ENGINE — Filed 04/18/2025

First engine blown 31,904 miles, Lifter failure. Replaced with re-manufactured engine. Second engine failure at 68,000 miles, Piston rod failure. Piston blew thru engine block and engine bay caught on fire.

AIR BAGS — Filed 02/19/2025

Airbag system did not deploy but smoke in cabin during a crash. Video of front, rear and inside cabin shows the rear end passenger side impact at an estimated 45-50 MPH. I saw smoke in cabin, disturbed with anxiety after crash waiting for bags to deploy accidentally. The airbag deployed red light illuminated notifying an airbag deployment. I received a GM message through the vehicle report application stating that my airbag system malfunctioned and I needed to take the vehicle to a service department for repair as soon as possible. This crash was a total loss of the GMC Sierra, this was how hard the vehicle was hit. Why did the airbag system smoke? Why did the airbags not deploy? Why did I receive a Malfunctioning Airbag system message from GMC? Video shows that if the airbag system would have deployed on the steering wheel I would have had less head and neck trauma when whipping backward and then forward.

UNKNOWN OR OTHER,ENGINE — Filed 06/14/2024

On [XXX] at approximately 3 pm I left my house and was traveling on [XXX] in Fort Mohave Arizona I was only traveling 7 miles. When I looked at the temperature in the cab was 121 degrees a few moments after the display system went black and never turned back on. I arrived at the store 4 minutes after the display shut off with no warning lights or any type of notification on my phone, I had rolled down the windows to get air in the cab to see if that would help cool down if needed. I was in the store 20 minutes. I returned to the truck turned it on and everything was normal, from there I drove back home nothing happened on my drive back the display was working. At 8 30pm I was traveling on [XXX] Driving towards a casino called Avi. I had the driver's side window halfway down when I smelled a faint plastic burn thinking it was coming from the outside because I had the window halfway down. That is when the cab of the GMC filled up with smoke that came in thru the air vents and flames started to show coming from the defrost vents and under the hood while I was driving. I had to stick my head out of the window to see where I could pull over without starting a huge brush fire. As I pulled over and the truck within seconds fully ignited into flames. Enough time to grab my belongings that I was able to save. My life was at risk by this vehicle igniting while I was driving. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

ELECTRICAL SYSTEM,SERVICE BRAKES — Filed 02/04/2024

My truck had smoke rolling out at work when I noticed it. Tried to put it out it Burnt my hands ! destroyed the inside I had it towed and insurance investigator said it was do to a brake controller for the trailer. And I took it to get estimate and the service dept said it was do To brake controller my truck was totaled my wallet toast my coat was toast my I phone my deposit my truck i drove daily to work out of and personal. General Motors would not help I called the. First. Then I was frustrated called my insurance they started a claim and low balled me now I lost 2 months of work bills stacked and low ball price on what the offer was) and haven’t gotten one yet. Called gm back they said I had an active claim they woundenr help it’s there defect I lost my job my mind etc on this. Two investigators state the same thing even there service dept. A gm service dept said the same thing. No warning indicators at al I will never buy another truck. The safety issue is people driving around not knowing. The 2500 and 3500 have them. Looked it up the plant that made my truck left the parts for manufacturing outdoors they got wet. It’s on the internet people r gionbg to get hurt. Lucky I was outside when my was on fire. Please help on the matter. Thank u

UNKNOWN OR OTHER — Filed 05/24/2023

I have HD surround vision cameras. I was parallel parking very slowly. The back end of my truck was in so I was watching the camera to see the front right of my truck and the back left of the other vehicle. I could see both vehicles including the road between them. There was space between the vehicles on the camera when I hit the other car. I called Sewell Buick Gmc and explained the camera might need calibrating. They sent a loaner car and picked mine up, When the driver arrived I explained the situation. It surprised his so I said get in my truck and put in reverse to activated the camera and watch me as I walk toward the right front tire. He saw mw as I approached, however, when I got right next to the tire I disappeared from she screen. GM said the vehicle was operating as designed. Operating as designed? They designed a SURROUND camera to show objects until they get next to the vehicle. Imagine if it was a toddler.

ELECTRICAL SYSTEM,ENGINE,FUEL/PROPULSION SYSTEM — Filed 02/06/2023

Less than 5 minutes after my husband and 2 children parked the car and came inside, a neighbor walking rang our doorbell to let us know there was something on fire in our driveway. We ran to the back to find his truck engulfed in flames coming from the engine. We quickly called 911 and exited the house/property. The truck continued to burn with 20-25 foot flames and very black smoke for about 40 minutes until the fire department was able to control the fire. The fire was hot enough that the entire engine was significantly burnt, the seats and steering wheel were gone, the glass shattered and melted, and the tires exploded and melted. Thankfully, everyone was out of harms way and safe through this incident. However, it has been extremely traumatic on my family and neighbors and has taken a lot of time and energy to try to deal with this. The car sat in our driveway for over 2 weeks with a very potent smell causing headaches until GM and our insurance finally investigated. There is damage to our siding, driveway, landscaping, basketball hoop, trampoline, and neighbors fence. The car was only 2 years old and scares me how quickly it went up in flames and how much worse this could have been either 3 minutes earlier or if it was parked in our garage.

SERVICE BRAKES — Filed 11/07/2022

The contact owns a 2021 GMC Sierra 1500. The contact stated that the grandson was driving in stop-and-go traffic, the braking system suddenly malfunctioned causing the vehicle to crash into the rear of a second vehicle. The grandson was driving approximately 10 MPH when suddenly while pressing the brake pedal to stop the message "brake failure" displayed before the vehicle crashed into the rear of the second vehicle. During the crash, no injuries were reported and a police report was taken at the scene. The vehicle was taken to the local dealer who replaced the master cylinder and brake booster and the failure was remedied. The failure mileage was 21,539

ELECTRICAL SYSTEM,AIR BAGS,ENGINE — Filed 04/17/2021

RETURNED HOME AFTER SOME SHOPPING. PARKED TRUCK IN DRIVE WAY. APPROXIMATELY 5 MINUTES AFTER RETURNING HOME MY WIFE SAW TRUCK SMOKING FROM UNDER THE HOOD. WITHIN ANOTHER MINUTE OR TWO THERE WERE VISIBLE FLAMES COMING FROM THE BACK EDGE OF THE HOOD. WE CALLED 911. WITHIN 5 MINUTES THE ENTIRE FRONT END OF THE TRUCK WAS ENGULFED IN FLAMES. THE FIRE DEPARTMENT ARRIVED AND PUT OUT THE FIRE BUT THE ENTIRE FRONT AND CAB OF THE TRUCK WAS DESTROYED. FIRE INVESTIGATORS DETERMINED FIRE STARTED AT BACK OF ENGINE COMPARTMENT NEAR BATTERY. VEHICLE WAS STOPPED PARKED IN OFF CONDITION. IN MY DRIVEWAY. NO MECHANICAL PROBLEMS WERE NOTICED ON RIDE HOME AND THERE WERE NO PANEL ALERTS FOR PROBLEMS.

ENGINE — Filed 01/14/2021

TL* THE CONTACT OWNS A 2021 GMC SIERRA 1500. THE CONTACT STATED THAT WHILE DRIVING AT 60 MPH, AN ABNORMAL NOISE APPEARED UNDER THE HOOD. WITHOUT WARNING AN EXPLOSION OCCURRED. THE CONTACT MANAGED TO VEER TO SHOULDER OF THE ROAD GET OUT THE VEHICLE TO CHECK AND SEE WHAT THE NOISE WAS. THE CONTACT NOTICED FLAMES APPEARED BY THE REAR WHEEL ON THE DRIVER SIDE. THE CONTACT GRABBED THE FIRE EXTINGUISHER AND EXTINGUISHED THE FLAMES. THE FIRE DEPARTMENT WAS CONTACTED HOWEVER NO REPORT WAS FILED. THE POLICE WERE CONTACTED BUT NO REPORT WAS FILED. THE VEHICLE WAS TOWED TO QUALITY BUICK GMC, INC (7901 LOMAS BLVD NE, ALBUQUERQUE, NM 87110 (505) 765 1300) WHERE IT WAS DIAGNOSED AND DETERMINE THE ENGINE WAS FAULTY THAT WOULD BE COVERED UNDER WARRANTIES TO REPAIR. THE VEHICLE WAS REPAIRED. HOWEVER, THE CONTACT FEELS UNSAFE DRIVING THE VEHICLE. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE STARTED AND STARTED AN INVESTIGATION. THE FAILURE MILEAGE WAS APPROXIMATELY 2,800.

SEATS — Filed 12/06/2020

REACHED FOR A FALLEN OBJECT BETWEEN THE DRIVER AND MIDDLE FRONT SEAT AND THERE IS A RAZOR SHARP PIECE THAT TOOK A LARGE CHUNK OUT OF THE HAND WHICH CAUSED HEAVY BLEEDING AND MEDICAL SUPPLIES TO STOP. THE VEHICLE WAS STOPPED AND JUST TRIED TO RETRIEVE FALLEN OBJECT BETWEEN THE SEATS. THE INCREDIBLY SHARP PARTS NEED TO BE CUT OR REMOVED FROM THIS AND OTHER SIMILAR VEHICLES OR COVERED WITH SOMETHING. IT WAS BARE METAL EXPOSED OUT WITH SHARP EDGES THAT CUT THE RIGHT HAND SO BADLY.