GMC Yukon sudden acceleration problems

Filed Apr 1, 2026 · Driver assistance · TX

What component or system failed or malfunctioned, and is it available for inspection upon request? The vehicle experienced a malfunction associated with a failed Over-The-Air (OTA) software update affecting electronic control modules. The (ECM), (BCM), and related electronic systems appeared to lose stability during operation. The vehicle attempted to reboot while being driven and displayed multiple system warnings. The vehicle is currently at the dealership and is available for inspection upon request. How was your safety or the safety of others put at risk?While driving, the vehicle began malfunctioning and attempting system reboots. The dashboard flickered, warning lights, and the vehicle exhibited unstable behavior. During a prior event, the vehicle experienced unintended acceleration and abrupt deceleration. This created a risk of loss of vehicle control, particularly in traffic. I have small children in this vehicle, and the unpredictable electronic behavior while in motion posed a significant safety concern. Has the problem been reproduced or confirmed by a dealer or independent service center? The dealership confirmed that a previous event was caused by a failed OTA software update. The vehicle has since malfunctioned again while driving and has been taken back to the dealership for further inspection. The dealership has acknowledged module instability and opened a TAK case with the manufacturer. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? The vehicle has been inspected by GMC1 dealership. A case has been opened with GM Customer Care. No police or insurance reports. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? 9 days prior to the first major malfunction, the check engine light illuminate. On April 1, the check engine light re-appeared and the vehicle attempted to reboot again while driving.

Filed Aug 3, 2025 · Driver assistance, Engine · MI

I had just backed the truck out of a parking space (while turning) and shifted the transmission into 'Drive' with my foot pressing the brake pedal (not the gas pedal). When I took my foot off the brake pedal in order to transfer it to the gas pedal the vehicle suddenly accelerated forward without my foot ever pressing the gas pedal. The vehicle traveled forward about 20 feet before I was able to stop it by pressing the brake pedal. I am a retired General Motors Safety engineer and I know I was not pressing the gas (accelerator) pedal when this sudden acceleration event occurred. I believe this type of event occurred one other time while I was driving this vehicle. However, I am not as clear about the circumstances surrounding this previous event.

Filed Jul 8, 2025 · Transmission · TN

My Denali had no previous problems, I pull out of the driveway and I felt a hard Lunge forward without me pushing the gas. Almost like the car accelerated like a hard jerk. I pulled over because I thought I had been hit by another car. After checking no cars around, I pull back out and I felt it again a hard lunge forward. If someone would have been in front of me I would have hit the car in front of me without even pushing the gas. These GMC are dangerous and can’t trust my vehicle. After getting stranded on the road found out the transmission went out. My suv is now being repaired at GMC at my expense. Only had the vehicle 6 months. Recall the transmission.

Filed Mar 4, 2025 · Engine · 34,000 miles · FL

The contact owns a 2023 GMC Yukon. The contact stated while her husband was driving at 75 MPH, the vehicle independently accelerated without depressing the accelerator pedal. The check engine warning light was illuminated. The contact stated that the transmission started to downshift, and the vehicle started losing motive power. The contact's husband merged to the side of the road and turned off the vehicle. While the vehicle was off, the message to press enter to start the vehicle was displayed; however, the vehicle failed to restart. The vehicle was then towed to a dealer and diagnosed with total engine failure. The local dealer was contacted; however, the vehicle was not repaired because the vehicle was not under recall. The manufacturer was not made aware of the failure. The failure mileage was approximately 34,000.

Filed Apr 14, 2023 · Fuel system · TX

Travelling on an FM road, going 55 when Yukon began accelerating on its own, even when I took foot off the accelerator. tapped brakes, thinking cruise control had engaged. Vehicle swerved violently. Speed kept increasing. Saw I was traveling 75mph! Braked hard! Felt as if acceleration was fighting against the brakes. Then spun out in the middle of the highway, spinning around 1 1/2 times while fully braking. Finally I slowed enough to throw it into park, regardless of what it might do to my transmission, I had to stop the vehicle. I came to rest straddling the lane I had been in and the oncoming lane, facing the direction from which I came. Traffic behind me had seen my struggles in time to stop back far enough that they weren’t endangered and there was no oncoming traffic at that moment. The fuel propulsion system (throttle?) seems to be at fault. There was no warning on the dash about any issue prior to this. The issue was real, a danger to myself and others. A mechanic examined the vehicle and discovered accumulation of debris on top of connector under the hood. He believed just enough water caused the conductivity needed to trigger the acceleration. State that these vehicles allow more intrusion from wheel well area than most. He thoroughly cleaned all connectors and no further issues have happened (yet!) Further research uncovered a report on ‘Sudden Unintended Acceleration’. The link follows: https://www.gmfullsize.com/threads/sudden-unintended-acceleration-gm-full-size-trucks.327479/ I also have a report quoting all the GM document #'s if need be.

Filed Apr 10, 2023 · Electrical · 20,000 miles · PA · crash · 1 injury

The contact owns a 2021 GMC Yukon. The contact stated that upon the start of the vehicle, the vehicle independently reversed without warning upon touching the gear shifter. The vehicle first reversed into a cement barrier and then lunged forward into an intersection while she repeatedly depressed her brake pedal to no avail. The contact managed to call 911 and while speaking with an operator, she was able to regain control of the vehicle. The contact crashed into a parked vehicle as well as a barrier during the failure. Once the contact regained control of the vehicle, she pulled into a gas station where she was met by police. A police report was filed. The contact suffered mental anguish as a result of the failure. Due to the failure, the vehicle was towed to a dealer where they were unable to duplicate or diagnose the failure. The vehicle was then towed to an independent body shop where it remained in their possession. The manufacturer had yet to be notified of the failure. The vehicle had yet to be repaired. The failure mileage was approximately 20,000. The VIN was not available.

Filed Nov 21, 2022 · Brakes, Engine · WI · crash · 1 injury

I call this a "Panic breaking defect" I have experienced this on two different GMC vehicles manufactured 14 years apart. The first was a 1999 GMC suburban with mechanically operated throttle control. The second was my present GMC Yukon XL Denali with electronic throttle control. The defect: The close proximity of the accelerator pedal to the brake pedal makes it possible to have the right foot on both pedals at the same time. This results in high engine RPM and full breaking pressure, however, the anti-lock breaking system releases and re-applies the break pressure repeatedly allowing the vehicle to lunge forward a short distance on each cycle. To remove ones foot from the both pedals so as to apply it to just the break would result in the vehicle, engine being at high RPM, to allow the vehicle to speed forward resulting in a serious collision. True one could use the left foot, if able, on the break and then remove the right foot, allowing the engine to return to idle but on modern automatic transmission equipped cars where the left foot plays essentially no part in driving, such an action is not likely to occur. Also the ignition key could be turned off but with both hands employed to apply maximum pressure on the steering wheel to ensure maximum braking effort, that is not likely to occur either, besides that would result in lack of power steering and vacuum boost to the break system. A proposed solution: In a drive by wire environment it would be simple to send an idle signal to the throttle body every time the break pedal is pressed and this is the condition which occurs in a normal breaking situation. I have related this to the service manager of my local dealer and have also communicated it to General Motors Customer Support even offering to demonstrate the problem but have received no response. After all I am only a lowly customer and it matters not that I am also a retired Engineer!

Filed Oct 17, 2019 · Acceleration · TX

2016 gmc yukon. Consumer writes in regards to unintended acceleration. *ld the consumer stated when the started it would lurch forward then reverse, 3 inches both ways. When idle the engine would rev between 400-600. Upon accelerating, the engine would vibrate and hesitate. It was discovered unfiltered air was being released into the engine. The filter was repaired. The engine longer revved, but continued to vibrate. On a separate occasion, the vehicle began rolling away after being parked. The consumer attempted reenter the vehicle thus being thrown to the ground. The consumer stated the gear shift freely moves which caused the vehicle to accelerate backward while on a hill. The vehicle rocks when in park and off and oil in the windshield center console leaked

Filed Apr 25, 2019 · Acceleration, Brakes · 10,000 miles · CA

On repeated occasions (from 2015 to 2019) I have experienced sudden acceleration at low speeds and sudden jerking motions. The transmission and speed controls are unpredictable and dangerous. This is hazardous and may result in a loss of control. I have also experienced numerous issues with the brakes including a stuck caliper at approximately 42,000 miles. I reported these issues and numerous other issues to gmc corporate, tustin buick gmc only to be told that it was a software issue and things are satisfactory and safe. Gmc contends that the vehicle is fine and declines to assist with issues. This is an ongoing issue. The date below is approximate. The mileage is approximate on all entries.

Filed Jun 29, 2016 · Engine · 26,000 miles · VT

I am writing to notify you about a problem with the transmission in 2015 gmc yukon xl. Gm is aware of a problem. They issued an internal notice to dealers in february 2016. However, they have not notified to owners in the form of a recall. On several occasions, my vehicle jumped forward, while driving in the city, when it was stopped, in drive, with brake engaged. I reported transmission problems to my local dealer but they repeatedly ignored my concerns. They kept giving excuses that didn't make sense. I finally pressed on, refused to take my vehicle back and reported the problem to several executives. The problem was finally diagnosed under different conditions as stated in the first internal document in march 2016. There was a problem with the transmission. They finally replaced the transmission for "one that didn't have a problem". Gm admitted there are problems with transmissions and the problem has been corrected in newer vehicles. They have yet to issue a notice to current owners that their vehicles are at risk. I owned a 2015 gmc yukon xl but chose to sell it over safety concerns and lack of appropriate response from gm corporate. With 2 young children, I spend a lot of time around schools (like most owners of large gm vehicles). I could have injured or killed someone. I feel it is my obligation to bring this situation to your attention. If you intervene, you can help to avoid any injuries in the future. It is clear that gm will not voluntarily protect the public.