GMC Complaints

Upper grill molding trim/bezel flew off truck. Part was recovered and clips look to have broken off. Plastic clips look to be insufficient and will break over time. Active recall for 2022 model vehicles only , needs to be expanded to 2023 or possibly further out.

I was driving on the highway below the speed limit when I heard a pop that sounded like a balloon and instantly the sound of wind getting into the car. I pulled over and found that the sunroof was rapidly shattering. I did not see a rock that had hit it. Maybe the tempered glass just exploded. I was not driving very close by any other vehicles at the time, but was on the highway.

I filed a complaint with NHTSA on November 3, 2025, about my brake system. Here is another one adding more information. I had to have another brake system part replaced. This time it was the brake booster. Cost $1441.63 (covered by extended warranty actual cost to me $100.00.) So far, I have had the booster sensor replaced twice, the vacuum pump and now the brake booster. I asked the mechanic how many parts related to this system were left to replace? This vehicle has 66,000 miles on parts for the braking system started needed to be replaced at 37,000 miles. The total cost for parts, labor is about $500. That does not include the loss of use for this vehicle which is about 15 days. Taking days off of work about 6 days. This has been a problem for GMC Terrains since 2015; there is still a problem with 2020 model year. Please do something before there is a loss of life due to brake failure.

I own a 2023 GMC Sierra 1500 (Black Widow Edition). The Truck has only 23000 miles on it. I experienced an Idle engine warning mid driving, and oil hot warning. It did Shutdown the engine of the vehicle and as I was trying to merge safely to the right lane and right side of the way the steering became very hard which put me and 3 of my employees in danger. After parking safely, I did call onstar and they ended up towing the truck while we waited for hours in the dark and cold temperature to get a ride. State police and Mdot did not show up even though we called them multiple times. This was a nightmare.

I purchased this 2025 GMC Acadia on 3/29/2025. About a week into owning it, the navigation stopped working. OnStar was able to reset my system. Then, about a month later, the vehicle locked my keys in the cabin without my knowledge. OnStar was able to unlock my vehicle remotely. Then, on 10/23/2025, I noticed my navigation was not showing my true location. I tried the Google Assistant, and it wasn't connected. After further investigation, my wifi hotspot was not working either, along with other connectivity apps. I researched how to manually reset my system and followed all prompts; that did not fix the problem. I pressed the OnStar button, and nothing happened; no connection. I thought that maybe the vehicle needed to cycle a few times. I let this continue for about a week before calling OnStar from my phone. They told me to press my SOS button; if it didn't connect, then I would need to take the vehicle to the dealership. So I took it to the dealership 11/6/25. They tried to download the update to my vehicle multiple times, over 6 hours at the shop, and the vehicle wouldn't accept the update. It is determined that the OnStar telematics control module is defective. The dealership says the part is backordered, and they do not have an ETA for arrival. After perusing the GM/OnStar forums, I am seeing that this is a repeated issue for many customers on vehicles as old as 2018, and the part doesn't come for 6 months or more in most cases. It does seem more prevalent with vehicles 2022-current. The issue here is that OnStar is touted as a safety feature, and I have been given 3 years of free OnStar service. I am unable to utilize the service (roadside assistance, accident assistance, and navigation) and many other features because of this. GM is aware that this is an issue, and the module is backordered when it should be readily available, since these issues seem to be commonplace. My brand new vehicle should work without issue and should be repaired promptly.

While driving at 70–75 mph on an interstate, my vehicle suddenly displayed a “Brake Failure” warning and limited speed to 62 mph. Power steering failed completely, and braking became ineffective despite hard pedal pressure. Multiple warnings followed: ABS, engine, and others. I was in heavy traffic with vehicles at full speed. Loss of braking and steering control forced me to coast across lanes to the shoulder, narrowly avoiding collision. My safety and that of others was at extreme risk. After stopping, I turned the vehicle off for ~30 seconds. Upon restart, all systems returned to normal—no warnings or issues. This indicates a transient software malfunction, not mechanical failure. No prior warnings or symptoms occurred. The problem has not been reproduced or confirmed by a dealer/service center. I have not scanned or inspected the vehicle. It has not been examined by the manufacturer, police, or insurance. The vehicle is in my possession and available for inspection upon request.

While driving at 70–75 mph on an interstate, my vehicle suddenly displayed a “Brake Failure” warning and limited speed to 62 mph. Power steering failed completely, and braking became ineffective despite hard pedal pressure. Multiple warnings followed: ABS, engine, and others. I was in heavy traffic with vehicles at full speed. Loss of braking and steering control forced me to coast across lanes to the shoulder, narrowly avoiding collision. My safety and that of others was at extreme risk. After stopping, I turned the vehicle off for ~30 seconds. Upon restart, all systems returned to normal—no warnings or issues. This indicates a transient software malfunction, not mechanical failure. No prior warnings or symptoms occurred. The problem has not been reproduced or confirmed by a dealer/service center. I have not scanned or inspected the vehicle. It has not been examined by the manufacturer, police, or insurance. The vehicle is in my possession and available for inspection upon request.

transmission locked up 8 times from 1,050 miles to current 3,885 miles. It has happens each time around 40 mph. Each time it’s like hitting the brakes. The 8th time it locked really hard like slamming on the brakes. I’m worried with winter months what will happen on snow/ice covered roads. Called dealership and was told GM refuses to do anything until it completely fails. It seems they know what the problem is but refuse to fix till the truck stops moving during complete failure. No warning lamps and dealer ship says they can’t replicate it.

I've noticed an issue since I picked up my vehicle from its last service where the RPMs stay around 1,000 when I let off the gas and should be coasting. The vehicle will continue to accelerate at 11 to 13 mph, and I really have to mash the brake pedal to stop. There is an update notice that popped up starting yesterday, but it will not install. Looks like the update is for the issue I am having. The update was supposed to be installed already per the service bulletin. Update number is N242452130

The contact owns a 2018 GMC Terrain. The contact stated that the transmission was shifting gear erratically. The contact stated that the doors were locking and unlocking independently, and the instrument cluster was blank. There was an abnormal beeping sound coming from the vehicle. Additionally, the contact stated that while at a traffic light, the Auto START/STOP feature delayed to respond. OnStar was alerted, but the contact declined to perform the service. The contact was in contact with the independent mechanic who sold the vehicle, but no assistance was provided. The local dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted, but no assistance was provided. The failure mileage was approximately 130,000. The VIN was not available.