GMC Complaints

The system that failed was the brakes, The car is availble for inspection. My saftey and others was put at risk due to not having brakes to stop. The problem has been confirmed by a dealer as a master brake cylinder failer The vehicle has been inspected by the dealer. There were warning lamps, message and other symptoms of the problem prior to the failure. They first appearead on December 4 2025

On Christmas Day 2025 my Tailgate flies open on its own and I see my cargo flying out and a piece of it bounced off my taillight passenger side braking the taillight and then when attempting to pull over my lane departing feature try’s to correct its self and I hit the median luckily at slower than I was going but enough to make a decent dent on front bumper

I experienced the brakes squeaking on and off for a few weeks this past summer. When at the dealership for an oil change, I was told the brakes pads were still good and the squeaking is common, especially during hot humid weather. Since then, I have lost the brakes twice. Both times, the pedal went all the way to the floor without resistance and after a few seconds, they came back like nothing happened. There was no warning at all. I have also experienced a complete blackout on my dashboard for about 30 minutes without known reason. On a separate occasion, the battery died for no reason. There have been times that a message is displayed on the dash to service rear turn signal lights. They flash fast as if they were out, then the next time I drive the car, they are completely normal. From what has been reported, there are some serious concerns with the 2024 Acadia. I have leased 3 Acadia's before this one and have never experienced anything like this. The brakes failing completely could have ended very badly for myself and/or others. There are several other reports of this nature. Please look into recalling this vehicle to prevent fatalities!!

Car will not shift into park therefore I cannot turn the car off without disconnecting the battery. Dangerous bc you don’t know if the car is in park or not when you have to get out and stand in front of car to life hood and disconnect battery.

The engine experienced a catastrophic mechanical failure after the vehicle had been inspected by the manufacturer and certified as compliant with an engine recall. The failure occurred after the recall remedy/inspection was completed. The engine lost functionality while the vehicle was in use, resulting in loss of propulsion and the vehicle becoming disabled, requiring towing. The engine is currently available for inspection and is awaiting major powertrain repair at an authorized dealership. The sudden engine failure created a safety risk due to unexpected loss of power while driving. No collision occurred. The issue has been confirmed by an authorized dealership. The vehicle had previously been inspected by the manufacturer as part of the recall process prior to the failure. Prior to the failure, there were no known warning lamps or messages indicating an imminent catastrophic failure. The failure occurred after the vehicle had passed the recall inspection. This appears to be a post-recall remedy failure. I am concerned that the recall inspection did not adequately prevent the known defect, as the engine failed after being certified as compliant.

Summary of Issue On [XXX], my family and I departed Kansas City, Missouri, for a camping trip to Great Smoky Mountains National Park (Cades Cove), Tennessee, approximately 800 miles away. We were towing a 2020 Forest River Salem FSX/RTX travel trailer, estimated at approximately 6,000 pounds loaded, using a Reese weight distribution hitch with integrated sway control. This load was well below the rated towing capacity of the vehicle. On [XXX], while driving without the trailer attached, the vehicle displayed multiple warnings including “Reduced Engine Power” and a transmission system alert. I immediately pulled over, shut the vehicle off, and restarted it. The warnings persisted. I cautiously drove approximately five miles to Twin City GMC, where the vehicle was diagnosed with a failed transmission valve body. Dealer and Manufacturer Response The service manager at Twin City GMC informed me that the required valve body was on national backorder, with multiple vehicles ahead of mine, and that wait times had reached up to three months. To confirm, I contacted Molle Chevrolet (Blue Springs, MO) and Randy Curnow GMC (Kansas City, KS). Both dealerships independently confirmed that this was a known and recurring issue, and that extended backorders for the valve body were common. I was informed that GMC could provide a daily rental allowance, but the rental vehicle would not permit towing. With my family, three dogs, and travel trailer stranded 800 miles from home, this option was not viable. As a result, I was effectively forced to trade in my truck and purchase a replacement vehicle to safely return home. Manufacturer Awareness and Complaint History GMC has demonstrated awareness of this issue through service bulletins, widespread owner reports, and media documentation addressing transmission valve body failures and parts shortages. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I live in Alaska. It was -13f. We were out and about and when I tried to leave and back up, the vehicle would not go into reverse. If it hadn’t been for a passing motorist my daughter and I would have been stuck there overnight, in negative temps. I was able to drive it home, in limp mode. Come to find out, it is the valve body on the transmission. That in cold temps the valve body can fail. After some research I found that it is a KNOWN issue with these vehicles and there has even been a “Urgent-Distribute Immediately” Service Update regarding the problem. Urging dealerships to review the VIN’s they have in their possession for the issue. I had the vehicle towed to a shop, where they confirmed the problem was the transmission valve body. They were unable to perform the work as it takes a qualified technician to replace. So it got towed to the closest GMC dealership. They have had it for two weeks now. They confirmed that it is a known issue and there have been no recalls. But they did tell me I was “in luck” because they stock that item so we won’t have to wait for a part. Not only is it going to cost me $3500 to replace something that is a know issue with this vehicle, but it could have ended in tragedy if no one would have come along when we were stranded. I urge you to make this a recall on these vehicles.

Vehicle Status: Brand New Current Mileage: Approximately 10,000 miles Incident Description On 1/8/26, while operating the vehicle on the interstate at highway speeds with cruise control engaged, the Check Engine light began to flash. Simultaneously, the vehicle’s warning system issued an alert stating that the engine oil was excessively hot. Immediately after these warnings, the engine began to emit a loud knocking sound and lost all power, shutting off completely while in motion. I was able to safely maneuver the vehicle to the shoulder of the road. Post-Failure Observations Upon inspection under the hood, I noted the engine was radiating extreme heat. I allowed the engine to cool completely before attempting a restart. While the engine attempted to turn over, it failed to start. Diagnostic Alerts Following the mechanical failure, I received multiple critical notifications via the GMC mobile app citing various engine failure errors. Summary Given that this vehicle is brand new with only 10,000 miles, a catastrophic engine failure of this nature is unacceptable. The vehicle was being operated under normal highway conditions when it became inoperable, posing a significant safety risk. I am seeking a full diagnostic review and a permanent resolution under the manufacturer's warranty.

While traveling at low speeds in parking lots and in the operation of parking, my 2016 GMC Sierra 1500 gets a hard brake pedal that goes to the floor but I have no brakes. I almost hit a person in a local grocery store parking lot, at the bank driving up to the ATM, and I almost lost my truck over a bank because the brakes failed. This has happened multiple times at low speeds but it is getting more consistent recently. It has endangered myself and others. It is only a matter of time until damage occurs or someone gets hurt.

With approximately 5,200 miles on my new vehicle, received an error message on the dash while driving on 1/8/2026 that read “Reduced acceleration; Drive with care”. I immediately took the vehicle to a local GM dealership and was informed on 1/9/2026 that due to a faulty thrust bearing (covered under the non-mandatory technical service bulletin 25-NA-307), the entire engine sustained a catastrophic failure and that the engine “tanked itself” and “grenaded itself”. Driving with the reduced acceleration mode active is beyond frightening as it’s very difficult to navigate traffic intersections in time to avoid oncoming traffic. It was also noted that it other cases where this faulty part causes the engine to totally fail, the vehicle becomes unusable at that point. I was informed that a replacement motor is not expected from General Motors for at least 2-3 months as this is becoming a more prevalent issue with certain 2025 Sierra’s with the 3.0 Duramax diesel motor.