GMC Sierra Complaints

15,732 consumer complaints on file.

#11665580June 8, 2025
ENGINE, FUEL/PROPULSION SYSTEM
Transmission has slipped and shuddered multiple times. We have had it diagnosed at gmc dealership and our mechanic, advising that it is 8L90 transmission failure. It will slip to lower gear abruptly, causing for possible safety issues especially on the highways.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665652June 8, 2025
ENGINE, ELECTRICAL SYSTEM, STEERING
My 2019 GMC Sierra Denali shut off suddenly while I was stopped in traffic. The engine died, the steering wheel locked, and the dashboard displayed warning messages including “ESC,” “power,” and another I didn’t catch. The truck would not restart despite attempts. The check engine light is now on. This happened without warning, and I had no prior mechanical issues. The vehicle is well maintained, garage-kept, and recently received a full service including oil change, brake work, and 75K-mile recommended service. I fear this is related to a known issue affecting other GMC engines under investigation for sudden power loss.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665444June 7, 2025
ELECTRICAL SYSTEM, UNKNOWN OR OTHER
Subject: Urgent Safety Complaint Dear GMC Customer Service, I hope this message finds you well. I am formally reporting a serious safety issue with my GMC vehicle. The car has experienced multiple dangerous incidents due to likely electrical or software faults, losing power suddenly on two occasions while driving. This is especially concerning given the low mileage of 20,000 km and that the vehicle is still under warranty. Vehicle Information: •Model: GMC Sierra SLE, 2024 •VIN: [XXX] •Current Mileage: 20,000 km Description of the Problem & History: 1.First Incident (At 3,000 km): oThe vehicle completely shut down due to an electrical or system software issue while driving. oThe vehicle was towed to the dealer and held for over two weeks for repairs. 2.Second Incident (Recently): oThe vehicle again lost functionality; the gear was stuck in 1st gear, and I was unable to manually shift. oThis occurred while driving, creating another unsafe situation. oThe vehicle was again taken to the dealer for repair, and to date, I have not been informed of the root cause. Actions Taken: The vehicle was brought to Sarhan, UAE (Sharjah), Al Ghandi Auto after the first incident. Despite inspections and repair attempts, the issue has recurred, indicating it was not resolved. And I am prepared to provide photographic or video evidence if necessary. Additional Context: •The vehicle is less than one year old and has been regularly serviced on time at authorized centers. The recurring issues strongly indicate an underlying reliability or manufacturing defect. Due to the severity and recurrence of these failures, I refuse any further repair attempts. I formally request either a full refund or a replacement vehicle, as this is unacceptable for a new car. Please acknowledge receipt of this complaint promptly and advise on the next steps for a swift resolution. Sincerely, [XXX] Phone: [XXX] Email: [XXX] Location: [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
#11665446June 7, 2025
ENGINE, POWER TRAIN, UNKNOWN OR OTHER
1. On 05/9/25, the exhaust emissions system malfunctioned, triggering diagnostic trouble code P2C7A (exhaust emissions system failure). This repair, the seventh attempt since June 2024, addressed the same recurring emissions issue previously involving replacements of components such as the NOx converter (02/18/25, 03/13/24) and EGR valve (02/18/25). The vehicle is available for inspection upon request. 2. The P2C7A failure risks limp mode, reducing vehicle power unexpectedly, which is hazardous on highways, especially while towing. Exhaust emissions system malfunctions release excessive pollutants, posing environmental and health risks to others. 3. Yes, the P2C7A code was confirmed by dealer during the 05/9/25 repair, following prior confirmations (e.g., 03/31/25–04/05/25. 4. The vehicle was inspected by Young Chevrolet-Cadillac during multiple repairs (e.g., 03/31/25, 05/9/25). 5. Yes, the check engine light and OnStar emissions alerts appeared prior to the 05/9/25 repair, first noted ~June 2024 (P2C7A onset). Exhaust smell and reduced fuel economy were observed intermittently. Symptoms persisted post-03/31/25 repair, leading to the 05/23/25 service.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665523June 7, 2025
ENGINE
The truck in question has LESS than 163k miles and burn a quart of oil a day, loss of power. There HAS been a recall on this SAME MOTOR 5.3 but while this year was ACKNOWLEDGED it was NOT a part of a recall EXCEPT for passenger side air bag that was replaced at dealership and damaged dash in process. Not it is NON DRIVE ABLE due to oil pressure issues
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665263June 6, 2025
ELECTRICAL SYSTEM, ENGINE, POWER TRAIN
I rely heavily on this vehicle for my business and within 1 year of ownership, the vehicle broke down on the highway allowing it to only run @ 30mph. After finally locating a dealer who could evaluate the vehicle in less than 1 week, I was informed that the part was unavailable and they indicated, "it could take 1 month or 3 months to receive." Following multiple conversations, I was forced to open a claim with GM Customer Care. While trying to get information, I was, at one point, told that "although the code indicates failed transmission control module, it doesn't happen all the time and if I wanted to drive it I could come and take it until the part arrives." That really told me alot about how GM representatives view SAFETY while when it happened, I was on Interstate and nearly got trounced by oncoming heavy traffic while pulling an equipment trailer. After the case was handed off to several GM Customer Care Representatives, I finally rec'd feedback including several email updates. I finally rec'd the vehicle back after 1 month and was informed that 1) would receive car payment from GM & 2) would receive additional compensation for lost work time while my vehicle was out of service (Jan 2024). Since that conversation, I did receive 1 car payment however, never heard back from Alisa regarding "lost time". I have sent several emails to customer care asking for an update however, crickets. Furthermore, the car has returned to the shop for another warning to "shift vehicle to park" when it was in park. They told me its a electrical malfunction but they could not get the error to come up on test. I have a photo showing the error.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665264June 6, 2025
ENGINE
There is a common lifter failure issue with the 5.3 V8 engine in these vehicles and local mechanics I've spoken too are very aware. The 6.2L was recalled for the same reason. GM would not honor or cover any of this as it was "out of warranty", however, I strongly feel this should be investigated.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665275June 6, 2025
ENGINE, UNKNOWN OR OTHER
Dealer keeps ignoring engine knock noise states its normal , mpg is down dramatically . Shift to park , vehicle only has 34k miles and dealer does not want to repair under warranty due to vehicle being a 2021 Battery keeps draining for no reason , new battery added still does the same thing
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665289June 6, 2025
POWER TRAIN:AXLE ASSEMBLY
The contact owns a 2017 GMC Sierra 3500. The contact stated while driving 30 MPH, there was smoke and a squealing sound coming from the passenger’s side rear wheel. The vehicle was taken to the residence and the contact observed fluid on the axle tube. The contact stated that the axle as taken apart and the wheel bearings were in pieces. The contact stated that the axle nut had unintendedly backed off. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 25,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665400June 6, 2025
ENGINE AND ENGINE COOLING
The contact owns a 2023 GMC Sierra 1500. The contact received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The local dealer was contacted and confirmed that parts were not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665118June 5, 2025
STRUCTURE:BODY
The top front grill became detached at highway speeds
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665124June 5, 2025
ELECTRICAL SYSTEM, FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
The instrument cluster shorted and was blank with no access to any gauges or speedometer. No functionality
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665149June 5, 2025
ENGINE
I was driving and entering the highway the truck lost power and acceleration was very slow, the engine fan runs 100% of the time, the check engine light comes on.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665190June 5, 2025
ENGINE
The engine failed and needs full replacement. Known GM issue with lifters. Engine style 6.2L. We contacted GM and they are not responsive and they provided a claim number. To repair is over 9,000$ and I still owe about 7000$ and the truck was purchased brand new. GM cannot furnish a replacement engine. The dealer showed 34 in stock when ordered. The dealer contacted us later stating GM canceled the order and they do not have an ETA when they can send an engine for the vehicle. We are paying on a vehicle that is stuck at dealer and cannot be repaired.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665100June 5, 2025
ENGINE, ELECTRICAL SYSTEM
Engine has had recall and still no remedy for it. Paint is chipping off and back locks stopped workingp
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665101June 5, 2025
ENGINE
On June 1 my 2023 gmc sierra 1500 6.2 began making a grinding and knocking sound on the engine no previous warning or symptoms. I believe it's a problem related to the engine recall so on June 2nd I took my vehicle to the dealership Brown Chevrolet of Eagle Pass TX where I was told that it would be about two weeks for them to get to it.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11665102June 5, 2025
ELECTRICAL SYSTEM, ENGINE, POWER TRAIN
Engine lifters failed. Heard ticking noise first day truck was purchased that gradually got louder but was told by gmc service shop it was normal to hear the ticking noise. Also when cruise control is on and you are decending a hill the rpms raise and you lose engine compression this will cause your speed to drop to around 20 mph and has happened nunerous times.. as well when making a turn sometimes or just driving the vehicle turns off while in motion and you have to coast to the side of the road and turn the key off and back on to start driving agsin.. the loss of power is a complete blackout no dash.. no engine nothing. As result of the lifter issue the engine also hard shifts in and out of slow gears.. I have not driven my truck in about a year and still owe 22k on it. The issues with this vehicle are the same as the recalled 6.3 v8 engines.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11664764June 4, 2025
POWER TRAIN
2024 GMC DENALI HD with approx. 12, 500 miles: The truck is constantly going into limp mode. Driving down the road, first it feels like the wheels lock up with a loud noise. Immediately goes into limp mode and check engine light comes on. Took it to the dealer yesterday 6/3/25 for repairs. I just spoke to my service advisor this morning where I was told it was the Valve Body of the transmission that needed to be replaced. However, they were on backorder and have no ETA on when they will get a replacement.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11664787June 4, 2025
POWER TRAIN
While driving on the freeway, my truck suddenly experienced a severe and unexpected downshift into first gear at highway speeds. Dashboard warning lights immediately illuminated, indicating multiple system faults. I was able to safely pull over and shift the vehicle into park. However, after doing so, the truck completely refused to engage drive or any other gear. This abrupt and uncommanded downshift posed a serious safety risk, not only to myself but to other drivers, due to the potential for loss of vehicle control. The vehicle had to be towed from the scene. It has now been at the dealership for over two and a half months, with no clear timeline for repair or resolution. This incident raises major concerns about the reliability and safety of the transmission system, particularly under high-speed conditions.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11664796June 4, 2025
FUEL/PROPULSION SYSTEM
- #5 injector failure, no. - Once the injector failed, the vehicle would violently shake when trying to accelerate. - Yes, was not covered under factory warranty but replaced by third-party extended warranty. -Yes, replaced by the dealership. -No warnings prior, once the injector failed warning for brake system check and vehicle mileage limits set in warning.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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