GMC Complaints

The LED left turn signal and blind spot detection ( safety feature) on the left outside rear view mirror suddenly stopped working. The is a TSB for warranty for 2016-2018 GM YUKON (#10-08-64-002D) and it states that the bulletin has been revised to include 2016-2018 year models for this defect. I am starting this claim because I am told by GM that my VIN is not covered under this warranty, yet I am experiencing the same issue stated in the TSB listed above.

Transmission on my vehicle has failed three times since I bought the vehicle in October of 2021. Vehicle currently has 39,000 miles. First transmission issue was resolved by the dealership by replacing the transmission valve body. This solved the problem for approximately 12,000 miles. In September of 2025 with 39,000 miles the transmission suffered a catastrophic breakdown which lead to complete transmission replacement. After being “fix” the vehicle suffered another catastrophic transmission failure within 400 miles of the complete transmission replacement. This incident caused the vehicle to shut completely down and I was stuck in the traffic lane of the US Highway. Fortunately my vehicle and I were not struck while waiting 30 minutes for a tow truck. Presently the vehicle is back at the dealership awaiting repair. From my review of available on-line information it appears there are 10’’s of thousands of GMC Sierra pickups with major transmission issues. This needed to be addressed before someone is killed due to the poor quality of these GMC trucks.

Valve spring snapped clear in half inside the engine while driving on the highway. This caused me to be stranded on the side of the road in the middle of the Arizona desert with my two dogs in the heat. Thankfully I did not lose control of the vehicle. No warning signs whatsoever until out of nowhere- vehicle check engine light started flashing as well as 'service stabiltrak' and 'traction control disabled'. I immediately pulled over. Thankfully I shut off the engine in time to prevent further damage to the pistons. Vehicle was towed and inspected by Holden's Auto Service in Kingman, AZ. Valve spring broke clean in half and was given to me after valve spring was replaced. Compression tests were performed after valve spring replacement. engine was run until warm and normal compression resumed. No other mechanical issues found. Checked for recalls on this vehicle. nothing found related to this.

my 2023 GMC Yukon Denali (VIN: [XXX] ), which is included in Safety Recall N252494003 for a known defect affecting the L87 6.2L V8 engine. My vehicle was first inspected under warranty in December 2024 at Serra Traverse City Buick GMC due to a burning smell. I was informed at that time that no issues were found. I was later told by the former service manager that the technician who evaluated my vehicle during that visit was let go due to poor workmanship and lack of product knowledge. Since that time, on two separate oil changes — January 8, 2025 and May 9, 2025 — my engine was found completely out of oil, with no oil on the dipstick. The documentation had to be retroactively added after my request. This pattern raises serious concerns about oil consumption or internal engine damage consistent with the recall defect. The dealership declined to replace the engine or perform any further diagnostics beyond the standard recall inspection. I was advised to retrieve the vehicle. However, I remain deeply concerned about the long-term safety and reliability of this vehicle, especially given GM’s acknowledgment that this defect may lead to engine failure and loss of propulsion. I have made multiple efforts to escalate this issue through both the dealership and GM’s customer service line. I was advised by Service Advisor [XXX] to contact the GM representative for regional review. He directed me to file a bbb claim.. Both GM and bbb denied my claim, stating out of warranty. However, the dealer explained that my issue were documented under warranty and would be handled appropriately if the issue persisted. GM contacted me an offered a $4000 credit. Unfortunately the problem still persist. I’m 3000 miles from being due for an oil change and again have no oil on my dipstick. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2020 GMC Terrain. The contact stated that while making a turn, the transmission shifted into neutral and briefly lost motive power and stalled. No warning lights were illuminated. The contact was able to restart the vehicle; however, the vehicle failed to function while shifting to drive(D) or reverse(R). The contact opened and closed the door to see if the vehicle would reboot. After several attempts, the vehicle returned to normal functionality. The contact stated that on a separate occasion, the transmission was leaking transmission fluid. The transmission was constantly slipping. The check engine warning light was intermittently illuminated. The vehicle was taken to the dealer, where it was diagnosed that the START/STOP accumulator in the cap was missing bolts, which caused the transmission to fail. An unknown code was provided to the contact. The vehicle was not repaired due to the cost. The vehicle was taken to various independent mechanics who confirmed that the transmission had failed. The manufacturer was made aware of the failure. The failure mileage was approximately 94,000.

The contact owns a 2016 GMC Canyon. The contact stated that upon attempting to leave the driveway, the vehicle was shifted into drive and the engine experienced a complete loss of automotive power, with several unknown warning lights illuminated. The contact stated that on a separate occasion, the vehicle lost power steering functionality while driving at 65 MPH, and the traction control and vehicle stabilization warning lights were illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed, and the contact was informed that the 4-WD assembly, steering electronic motor, steering angle sensor, and the electric belt drive rack and pinion steering needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure. The approximate failure mileage was 70,263.

I had a complete engine failure in my 2021 Yukon XL Denali while driving 70mph on the highway. My vehicle warning lights all of a sudden came on and my cruise control was disengaged. My vehicle started shaking and then started smoking. It was taken to our GMC dealership immediately and it was discovered that the engine had failed even though my VIN is not listed in the L87 Recall. No warning lights appeared prior to this failure. I will attached our invoice from the dealership and their description of the problems.

I looked up recall information on NHTSA.GOV site and found my car has a recall for engine problems. My GMC app says there are no recalls related to my vehicle and I have never received a communication from GMC stating a recall has occurred.

The contact owns a 2018 GMC Terrain. The contact stated that while driving at an undisclosed speed, the unintendedly decelerated and failed to properly accelerate. The vehicle was taken to the local dealer, who diagnosed the vehicle with transmission failure. The contact was informed that the transmission needed to be replaced. The transmission was replaced with a used transmission, but the failure reoccurred. The vehicle was taken back to the local dealer who diagnosed and determined that the replacement transmission had failed and needed to be replaced. The vehicle was not yet repaired. The manufacturer was not notified of the failure. The failure mileage was 53,000. The VIN was not available.

2021 GMC Sierra 2500HD 6.6L gas 6 speed automatic transmission W/4wd After a brake service job the vehicle will randomly kick on the traction control/ABS and the right front brake will lock up. The steering wheel jerk is violent enough to remove the wheel from the drivers hands. No Traction control or ABS lights flash on the dash when this occurs and it has caused the vehicle to veer into oncoming traffic and also off the road. The dealer was unable to recreate the issue nor are there any stored codes/issues found when having the truck diagnosed. ABS and speed sensor wires have been reviewed and none were damaged during the brake job. All wheel speed sensors are functional and reading when the issue happens. This issue happens during dry or wet conditions and is random without warning.