2018 GMC TERRAIN Complaints

We just got off the bus thruway and my brakes pedal got hard to press and it was hard to stop car I had to push on brake dry hard to get the car to stop it was jarring and o had to get my some and o to a safe place. Garage said it’s brake assist and he researched there’s is an active law suit against GM bc lots of Moses and models have this issue although they claim to know nothing about it

My car was t-boned on the driver side and no airbags deployed. The outer door and window exploded with the force. We were also hit from behind

The control knob that controls AWD, 2WD,Off-road, and 4 x4 AWD. Just stopped working. Stuck on 2WD mode. I did have it checked for any codes, even though, there is NO check engine light is on.

The contact owns a 2018 GMC Terrain. While attempting to shift to reverse(R) out of a parking spot, the message “Transmission Unable to Shift” was displayed on the instrument panel, and the transmission was unable to shift into reverse(R). The contact called for tow truck assistance. The vehicle was unable to shift into neutral (N). The contact stated that prior to the transmission failure, the “Service Transmission Soon” message was displayed. The vehicle was towed to a local dealer to be diagnosed, and it was determined that the transmission had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 245,000.

Faulty Brake Vacuum Pump!!!! 2018 GMC Terrain @ 119254 miles--- NO warning! Brakes were hard to press, did not work and I rolled into ditch to prevent an accident. I see hundreds of people with same issue now that I Am having to research. This was very scary. I was told it was as a brake booster pressure sensor. But that was not the problem. It is the brake vacuum pump. This is so dangerous. Why is GMC not correcting this issue? This is insane. GM issued multiple technical service bulletins on vacuum and booster issues starting in 2017. Why hasn't anything been done?

Vehicle will not shift out of park, despite replacing the valve body, putting in a new battery, and transmission fluid. It has been this way since mid January. The codes don’t make sense and there is no current recall, nor have we had this vehicle for very long. It has 48,000 miles on it and is having this issue. Very disappointed.

Brakes were hard to engage or press when stopping due to Vacuum pump stop working. Had to replace the vacuum pump

The contact owns a 2018 GMC Terrain. The contact stated that while driving at various speeds, there was an abnormal grinding sound coming from the vehicle while transitioning to 4WD. The contact continued driving and the driving sound became more frequent while shifting into 4WD. Upon inspecting the vehicle, the contact discovered that the driveshaft had detached and was hanging down from the suspension. An independent mechanic was contacted, and the contact was informed about NHTSA Campaign Number: 17V516000 (Power Train); which the mechanic associated to the failure. The contact called two local dealers and was informed that the VIN was not included in the recall. The manufacturer was notified of the failure, and the contact was referred to the NHTSA Hotline to report the failure. The vehicle was not repaired. The failure mileage was approximately 160,000.

Turbo boost went out in my vehicle and 3 others with the same engine, different makes/models. Vehicles were serviced at Grayling Car Care 4430 M-72, Grayling, MI 49738 (989) 348-3200. Significant power loss, sluggish acceleration, poor fuel economy, and often strange noises (whining, grinding), accompanied by blue smoke from burning oil and a lit check engine light, with the severe risk of catastrophic engine damage from broken parts entering the engine if driven, requiring prompt replacement. It's generally unsafe to drive with a bad turbo, as metal fragments can destroy the engine.

The infotainment system will just randomly start going haywire and when it happens, you cannot use the touchscreen. It will try to randomly delete app icons such as the camera, it will try to delete connected phones, it will try to delete radio favorites and it will move app icons all around. These are just a few examples of things that happen.