GMC Sierra Complaints (2015)
916 consumer complaints on file.
- #11667151June 16, 2025ENGINE
Blown head gasket. Engine hydro-locked.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11665980June 10, 2025SERVICE BRAKES, HYDRAULIC
The contact owns a 2015 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the brake pedal was depressed; however, the vehicle failed to stop as intended. No warning lights were illuminated. The contact noticed an abnormal sound, and the vehicle rolled forward before the vehicle stopped. The vehicle was taken to the dealer but was not diagnosed. The dealer was made aware of the failure. The contact was informed of an unknown recall; however, the recall repair had expired. The contact had not received a recall notification. The vehicle was not diagnosed or repaired by an independent mechanic. The manufacturer was made aware of the failure and confirmed that the recall had expired in June 2024. The contact was advised to contact the NHTSA Hotline to report the failure. The failure mileage was approximately 75,000.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11662568May 22, 2025ENGINE AND ENGINE COOLING
See attached document for complaint.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11659756May 8, 2025SERVICE BRAKES, HYDRAULIC
The contact owns a 2015 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the brake pedal was depressed; however, the vehicle failed to stop as intended. The vehicle was taken to the dealer; however, the vehicle was not diagnosed. The vehicle was not repaired. The contact stated that the failure became a persistent failure. The manufacturer was made aware of the failure. The contact referenced an unknown recall repair as a possible cause of the failure; however, the VIN was not included. The failure mileage was unknown.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11657986April 30, 2025POWER TRAIN
A valve spring broke while going around 40 mph. Was not accelerating when it happened. Destroyed the piston, head and cracked the block. Once apart found the AFM lifter had started to wipe a lobe on the cam. Engine shut off after running real rough luckily my son was able to pull over. Truck had regular service and taken good care of. My favorite truck I have ever had. Had 137,000 miles on the odometer. This could have ended badly.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11658005April 30, 2025ENGINE
With all the GM engine problems being recalled, the known issue witht he AFM/DOD on all the models 2013 and up on 5.3L and 6.2L engines should have been recalled. The valves are known to collapse and nending push rods, causing damage to the cam shaft. This can cause ht eengine not to run. The symptoms and possible icidents include the same as the current recall NHTSA Campaign Number: 25V274000. My engine has been repaired twice now due to this AFM/DOD issue. I have all the paperwork from GM dealer that repaired it. I will upload the first repair, I need to scan the second repair. The engine is now making the ticking valve sound ans the vehicle is services regularly. What component or system failed or malfunctioned, and is it available for inspection upon request? AFM/DOD valves collapse causing enegine damage. How was your safety or the safety of others put at risk? Lack of power while driving, loud engine knock Has the problem been reproduced or confirmed by a dealer or independent service center? Yes, by the dealer Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Insepcted by the dealer, and only the damaged parts replaced, not all the valves that can still collapse. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? No warning, engine light came on due to misfire on both incidents.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11657768April 30, 2025FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP
The contact owns 2015 GMC Sierra 1500. The contact stated that while driving on several occasions at various speeds, the vehicle lost motive power. The contact stated that the check engine warning light was illuminated for approximately a month. The vehicle was taken to an independent mechanic and the contact was informed the high-pressure fuel pump was leaking fuel into the crank case, and the high-pressure fuel pump needed to be replaced. The vehicle was repaired; however, the failure reoccurred approximately 1 year and 5 months later. The vehicle was taken to an independent mechanic where it was diagnosed and determined that the high-pressure fuel pump needed to be replaced. The vehicle was repaired. The contact stated that on several occasions while driving at various speeds, there was a loud sound coming from the engine compartment. The vehicle was towed to an independent mechanic where it was diagnosed that the fuel injectors on one side of the engine were not working properly, and that the fuel injectors needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 178,137.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11657524April 29, 2025ENGINE
The contact owns a 2015 GMC Sierra 1500. The contact stated while driving approximately 50 MPH, the vehicle started to lose motive power and then stalled. The contact stated that there was a black cloud of smoke coming from the exhaust pipe. The check engine warning light was illuminated. The contact had the vehicle towed to an independent mechanic. The vehicle was diagnosed, and it was determined that the rod bearings had failed and needed to be replaced. The vehicle was not yet repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 122,000.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11657568April 29, 2025ENGINE
The contact owns a 2015 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle stalled with the check engine warning light illuminated. The vehicle was able to be restarted. The vehicle was taken to an independent mechanic, where it was diagnosed that the engine had failed and needed to be replaced. The vehicle was not repaired. The vehicle was taken to the dealer, where the diagnostic result was confirmed. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 97,000.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11656978April 26, 2025SERVICE BRAKES
I've had problems with the brakes for several years, the pedal is very hard at low speed. I've seen a recall but not on my car???
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11655854April 21, 2025SERVICE BRAKES
"NHTSA campaign: 19V645000 AS the vacuum level drops, the brake assist decreases, increasing braking effort, extending the distance required to stop the vehicle, thereby increasing the risk of a crash." Our vehicle was serviced and repaired for this problem under the recall on 9/6/2019, however, it is now happening again. Is there a second recall for this problem, and/or what can be done to remedy the defective equipment?
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11655406April 18, 2025POWER TRAIN
The contact owns a 2015 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the transmission was difficult to shift into gear, with the check engine warning light illuminated. The vehicle was taken to an independent mechanic but was not diagnosed or repaired. The dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 144,000.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11654944April 16, 2025ENGINE
The contact owns a 2015 GMC Sierra 1500. The contact stated that while the vehicle was parked and occupied at the residence, the contact exited the vehicle and went inside his home; however, forty minutes later, while attempting to start the vehicle, the vehicle failed to respond as needed. The contact stated that a bystander inspected the vehicle and assumed the starter had failed. No warning light was illuminated. The vehicle was towed to the dealer, where it was diagnosed and determined that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and suggested that the contact take the vehicle to the local dealer for assistance. The approximate failure mileage was 141,000.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11651825March 31, 2025SERVICE BRAKES
upon applying brake pedal at low speeds the brake is hard to depress and "choppy" in reacting. this seems same as N192268490 Increased Brake Pedal Effort yet the gmc denali is not apparently in the recall. This has happened on several occassions.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11649900March 22, 2025SERVICE BRAKES
The brake system failed in a parking lot three times within a month. It’s related to the special policy and recall regarding the vacuum and the loss of brakes at slower speeds and in reverse. The first two accidents were very minor creating no damage. The third one was at 10mph when I lost my brakes and crashed into a concrete barrier in a parking structure causing significant damage to my truck. I did not get injured but I have a wife and two kids that I am so grateful were not in the truck for the third one with major damage. With that being said my son was in the truck the second time it happened when I crashed into a parked vehicle in a parking lot because I was unable to stop which made me very frustrated and worried for my families safety in my truck. The first accident was in a parking lot where I was backing up and lost the brakes and crashed into a building which is my veterinary office causing damage to the building. Therefore after the first crash due to this issue I have decided that driving with my family in the truck is not an option anymore. It is very disappointing that a truck I purchased for the functionality and safety of having my wife and kids in it is no longer safe for passengers or myself in it. This problem is very reproducible and is a major concern for my family and my safety. It was towed to a GMC dealership in Waukesha and is being inspected and they have stated it is reproducible. No warning lamps or messages were indicated for this issue. The truck will next need to get towed to Crash Champions auto body repair to ultimately get repaired which will take another month. All of this is a major inconvenience as I am a full time firefighter and in paramedic school as well. Not having a reliable safe vehicle for an extended period of time has caused great stress and inconvenience to my family. I’m hoping and praying that something can be done about this quickly and promptly to make this right. Thank you.
- Crash:
- Yes
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11648677March 17, 2025STRUCTURE:BODY
N242490120 is applicable for 2022 models but my 2023 also had the same problem; The grille upper cover broke at the taps and detached from the grille structure.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11648678March 17, 2025POWER TRAIN, ENGINE
Motor blew up while driving down the road. Had to replace motor on 08/23/2023 at about 116,000 miles. Left me and my family stranded in the middle of no where. Was going around 60 miles an hour and when passing someone got up to 71 mph and then motor blown push rod bent. Transmission issues. Hesitation when switching from park to drive/ reverse. Takes at least 40 seconds and when you accelerate it will jerk so hard. Will lunge forward very sudden and sometimes even when coming to a stop at a stop sign. This happens almost every day.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11648765March 17, 2025POWER TRAIN
I believe the torque converter failed and resulted in the transmission starting to fail. It still goes down the road but shudders when slowly gaining speed
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11646409March 5, 2025ENGINE, POWER TRAIN
In the fall of 2023 my 6.2L V8 with only 107,565 well maintained Miles completely seized up and shut off without any warning lights or other indications of failure. I was going up a steep hill and luckily I was able to get to the side of the road by coasting backwards to a stop and fortunately no one else behind me at the time. I did not get my truck back until late spring of 2024. I paid over $13k out of pocket to replace the engine because of this issue that is known to many other GM truck owners. Prior to catastrophic engine failure I’ve had multiple services including replacement of torque converters which would cause the truck to shake violently when shifting along with violent shifts in the 8 speed transmission and at times the feeling of being rear ended when slowing down or coming to a stop which GM claims to be “normal operation”. The engine failure was never investigated by any other parties but was looked at by the dealership service department. Both violent shifts and torque converter shutter were also confirmed by the dealer but only fixed with what I consider to be temporary remedies.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11644591February 24, 2025EXTERIOR LIGHTING
Lack of illumination of headlights straight ahead. No light shines to the sides of the vehicle making it difficult to see left or right when negotiating a turn at night. I have put new bulbs in both sides the best money can buy at CarQuest with no improvement. The headlight lenses are not dirty or fogged over. It appears to be a design problem, and I have seen other people with this model truck complain about the same thing on some blogs. I contacted GM directly looking for information I can get on a possible upgrade, and they have offered not solution. I have had this issue with this vehicle since buying it used 4.28.2018
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0