GMC Sierra Complaints

15,732 consumer complaints on file.

#11759584August 25, 2026
UNKNOWN OR OTHER, EXTERIOR LIGHTING, ELECTRICAL SYSTEM
My 2025 GMC Sierra 2500 experienced repeated electrical failures that caused complete battery drainage and multiple overnight no‑start conditions within the first year of ownership. These failures occurred in extreme desert heat, where temperatures in [XXX] reach 120°F. A vehicle that repeatedly fails to start in these conditions creates a serious safety hazard, including risk of heat‑related medical emergencies if stranded. The defect persisted despite multiple repair attempts and two battery replacements. The dealership ultimately told me I would “need to replace batteries as needed,” instead of diagnosing the underlying electrical issue. Detailed Description of the Problem Multiple overnight no‑start incidents Several jump‑start events required XXX – 15,265 miles: Battery replaced due to electrical drainage XXX: Battery replaced again for the same defect Electrical system continued to fail after repairs Dealer advised ongoing battery replacement rather than addressing root cause The truck was unreliable and unsafe in extreme heat. A no‑start condition in 120°F temperatures can leave occupants stranded without air conditioning, posing a life‑threatening risk. Frequency of the Problem The electrical failure occurred multiple times over several months, including late 2025, early 2026, and again in mid‑2026. The defect was consistent and repeatable. Consequences Risk of being stranded in extreme heat Loss of air conditioning during no‑start events Potential for heat exhaustion or heat stroke Vehicle unreliable for daily use Safety hazard for driver and passengers 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
#11759601August 25, 2026
ENGINE
Engine went into limp mode and engine is no longer good
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11758980August 24, 2026
VEHICLE SPEED CONTROL, FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL, VISIBILITY/WIPER
Cruise control activates at speeds between 1-5mph, which frequently happens while turning, parking, or going through a drive-through. The cruise control activates by a toggle on the left spoke of the steering wheel, which can be easily bumped while doing low-speed maneuvers like parking. When bumping the toggle, the cruise indicator shows a set speed of 15-18 mph, and the vehicle surges forward trying to attain that speed. Since this occurs while maneuvering to park, it creates a dangerous situation if anyone is nearby and you are unable to react in time. This is an ongoing problem that can be duplicated at will. Rear backup camera very dark at night it’s unusable.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11758996August 24, 2026
ENGINE
Engine completely failed and had to be replaced
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11759035August 24, 2026
ENGINE
I purchased my 2020 GMC Sierra 1500 AT4 with the L87 6.2L V8 new from a GMC dealer in March 2020 for $65,910 (VIN [XXX]). The truck has primarily highway mileage, very little towing, and has been well maintained. At 166,634 miles on [XXX], the truck developed a flashing check-engine light. The GMC dealer diagnosed “Cyl 3 lifter failure with camshaft damage” and determined that replacing the engine was preferable to repairing it because of the vehicle's mileage. The dealer installed a replacement OEM GMC engine and replaced both broken engine mounts. The replacement engine and installation cost $11,778. The replacement engine has subsequently required multiple repairs. At approximately 170,411 miles, the GMC dealer documented an exhaust leak that had occurred since the engine repair and a coolant leak from the upper radiator hose; both were repaired. At approximately 187,699 miles, the truck experienced overheating, coolant leakage, and loud engine-area noise. The dealer found that the water pump was coming apart and replaced the water pump and related components. I am reporting this vehicle because it is a 2020 Sierra equipped with the L87 6.2L engine and experienced catastrophic lifter/camshaft failure requiring complete engine replacement, followed by multiple engine-related repairs. I believe this history is relevant to NHTSA's investigation of L87 engine failures in earlier model years and warrants consideration when evaluating whether the known L87 engine defect extends beyond the vehicles currently covered by the recall. 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
#11759053August 24, 2026
ENGINE
The engine blew
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11759066August 24, 2026
ELECTRICAL SYSTEM
The contact owns a 2026 GMC Sierra 1500. The contact stated that intermittently there was no sound while the turn signals were activated, and the radio and incoming calls failed to be audible. The issue often lasted all day or for an hour or two before returning to normal. The contact associated the failure GM Technical Service Bulletin: PIT6406 (or PIT6406F), but the dealer stated the vehicle was not included in the bulletin and refused further diagnostic tests. The vehicle was taken to a dealer to reprogram the Audio Control Module (ACM) because the software was outdated, despite the vehicle being brand new. The reprogramming was completed; however, the failure was not resolved. The manufacturer was notified of the issue. The failure mileage was 3,657.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11759074August 24, 2026
SERVICE BRAKES, HYDRAULIC:PEDALS AND LINKAGES, VEHICLE SPEED CONTROL:ACCELERATOR PEDAL
The contact owns a 2015 GMC Sierra 3500. The contact stated that the brake pedal and accelerator pedal lifted while depressed, causing the engine to rev. There were no warning lights illuminated. The dealer was contacted and made aware of the failure. The vehicle was not taken to the dealer to be diagnosed or repaired. The manufacturer was not informed of the issue. The failure mileage was approximately 37,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11759144August 24, 2026
LATCHES/LOCKS/LINKAGES
The contact owns a 2024 GMC Sierra 3500. The contact stated that the tailgate frequently opened independently while the vehicle was parked. The vehicle was previously repaired under NHTSA Campaign Number: 24V060000 (Latches/Locks/Linkages); however, the failure persisted. The vehicle was not diagnosed or repaired by a dealer or an independent mechanic. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was approximately 40,600.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11759239August 24, 2026
ELECTRICAL SYSTEM, ENGINE, POWER TRAIN
Our 2020 GMC SIERRA 1500 has suffered catastrophic systems and engine failure including the brakes multiple times for almost 4 years. It has happened in high traffic and on the interstate each time having to be coasted off of the road to come to a rolling stop. There have been nine repair attempts with GM dealers repeatedly stating the issues were repaired and returning our vehicle to us. We began making the CEO and Executive team aware of the potentially deadly safety hazards including the fact that I, [XXX] am disabled and power wheelchair dependent requiring a truck that can carry my power wheelchair. We have sent numerous emails to Ms. [XXX] and the Executive team numerous times informing them in detail, each time, of all issues involved. We started communicating via phone and email with customer care to no avail. All attempts at repair finally ended in complete engine failure leaving us with an estimate to replace the engine of over $13,000. We have also, submitted a detailed complaint to the Attorney General’s Office and after review were given the Case # TCP - XXX. I will attach the Complaint and Addendum sent to the Attorney General along with two of the emails sent to Ms. [XXX] and her team informing her of all issues with the truck. They took no action to actually help us get this truck off of the road knowing it was having catastrophic engine and system failure and that it had to be driven to transport a disabled power wheel dependent with severe medical issues and the medically necessary power wheelchair. I am also attaching the earliest OnStar Diagnostic notice of Engine, Transmission and Emissions system issues from May of 2023. The issues have remained the same from the beginning only worsening though my husband has only driven the truck in town on slower less busy streets learning how to make adjustments such as pumping the brakes and starting and stopping the truck to keep it going. My carrier is installed and yet it is undrivable. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATIO
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11759264August 24, 2026
ENGINE, BACK OVER PREVENTION: REARVIEW SYSTEM BRAKING, BACK OVER PREVENTION: WARNINGS
Piston 5 dropped compression to 120 the rest were 190-200. The engine failed therefore none of my parking assist sensors were working and I backed into a car because the truck was misfiring.
Crash:
Yes
Fire:
No
Injuries:
0
Deaths:
0
#11759266August 24, 2026
ENGINE
The 2025 GMC Sierra 1500 with 18,675 miles and the 6.2 gas engine failed during a road trip. I was on my way from [XXX] to [XXX] on the Interstate when about 7 hours in, just outside [XXX]. I was noticing a lack in power when I pulled out of a rest area. The truck would not accelerate over 60mph. I slowed down and as I was pulling off the side of the interstate, the truck died. There was knocking sound as I started to pull over. I attempted to restart the vehicle; it did not restart. I called roadside assistance and the tow truck to myself and the truck into Edwards Chevrolet Cadillac in [XXX]. They diagnosed the issue as spun or bad bearing in the engine, and it would need replaced. They told me that the last 6.2 engine took 60+ days to receive and they were now on backorder, plus they already had a truck in the shop waiting for one. There were no warning indicators on the console, and all my service has been done at GM dealers. The biggest safety issue was being stuck on the side of the interstate with rushing semi's going by. I was also going to be stuck in [XXX] until a resolution was found. I ended up purchasing a new 2026 GMC Denali Ultimate with the 3.0 diesel. It was the closest package that was on my 2025 and I wanted to stay the same, minus the 6.2 engine. 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
#11759295August 24, 2026
POWER TRAIN, ENGINE
The 5.3L Engine active fuel management failure problem. This known problem with the GMC motors was not disclosed by any dealerships or the manufacturer. While driving down the roadway, the truck had an engine malfunction and I was fortunate enough to be able to safely pull over. The check engine light activated and I took it to the dealer the next day. I was informed by the dealer that this was a known, common issue that GM was aware of but was not offering assistance. I had to pay $11,000 out-of-pocket because of this.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11758828August 23, 2026
ENGINE
The oil recall on my truck has been completed, but the low oil light still comes on. They changed the weight of the oil stated that it didn’t fall Under the engine replacement recall. All that was done was a new oil cap and change weight of oil. Did not solve anything.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11758858August 23, 2026
ENGINE, FUEL/PROPULSION SYSTEM
Sudden loss of propulsion while driving on I-75 with cruise control engaged. Vehicle began to decelerate. Pulled off onto emergency lane. Engine was idle-ing roughly. Would not increase rev when gas pedal pressed. Shut down. Tried one restart. Unsuccessful.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11758867August 23, 2026
FUEL/PROPULSION SYSTEM, ENGINE
Driving on I-75 with cruise control engages. Vehicle began decelerating. Pulled over onto emergency lane. Engine idled roughly. Shut down. Attempted one restart unsuccessfully.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11758888August 23, 2026
ENGINE
I, [XXX], am currently getting my engine replaced for the 1st time because of An engine failure. Engine completely shut down in the mountains while I had my 3 young kids ([XXX], [XXX] & [XXX] old) on our way to our vacation. 102 degrees outside no ac, no water for 4 hours until a tow truck finally came. The kids were scared for their life due to being on the side on the road, hungry with nothing to do but wait. Literally had just enough clearance to get on the side of road where vehicles drive-55-65 mph. Avenal, Ca to be exact. What’s the best way to get my money back? I do not want to continue to deal with these problems on the road with my little ones. The dealership is currently looking to replace my engine and waiting on parts. There has not been an official date I will get my vehicle back. Thank you in advance. 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
#11758900August 23, 2026
ENGINE, POWER TRAIN
I got the vehicle with 60,000 miles 8,000 miles in vehicle gave me problems gave me a check engine light code p0300 then took it to get inspected then was told it was the fly wheel then it’s started knocking vehicle is currently not being droven because of the fly wheel
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11758917August 23, 2026
STRUCTURE:BODY
August 5th, 2026, I was driving South on I-55 between Hammond and Ponchatoula at 70 mph when the top grill trim (Bezel) flew off, hit (and cracked) the windshield, and landed somewhere behind my traveling vehicle.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11758920August 23, 2026
ENGINE
This engine has used more than 2 quarts of oil since purchased in November of 2025. It has 12,000 miles on it. The exhaust pipes are covered in black soot from oil burn. It scares me to drive it, $87,000 retail vehicle worth about nothing with a bad engine. Terrible
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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