2020 GMC TERRAIN Complaints

The contact owns a 2020 GMC Terrain. The contact stated that after starting the vehicle and shifting into reverse(R); the rear-view camera screen was not functioning as needed. There was no warning light illuminated. The message "Service Rear Camera System" was displayed. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 53,500.

Brakes stopped working while driving. Yes it has been reproduced by mechanic. No it has not been inspected by manufacturer. “Service Brake Assist” message populated after failure.

The contact owns a 2020 GMC Terrain. The contact stated while reversing, the rearview camera screen displayed a blue image. There was no warning light illuminated. The dealer was notified of the failure and informed the contact that a fee would be charged for a diagnostic test. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline. The failure mileage was approximately 104,000.

The contact owns a 2020 GMC Terrain. The contact stated while driving 20 MPH, while attempting to slow down, the brake pedal was depressed; however, the brake pedal felt abnormally stiff. In addition, the vehicle hesitated to come to a complete stop. The contact became aware that the driver's side and passenger’s side struts had failed. The check engine warning light was illuminated. The vehicle was taken to the dealer where it was diagnosed that the brake vacuum pump needed to be replaced. The brake vacuum pump was replaced, and the vehicle was repaired. The manufacturer was notified of the failure and referred the contact to the dealer for assistance. The approximate failure mileage was 17,361.

In September 2024 i was driving down the freeway and my car shuttered like the transmission was slipping. I then proceeded to get over into the right hand lane incase i needed to pull over thankfully, because then i lost use of my breaks, and then my ability to accelerate and steer. Then my car just shut off and would not stop. My vacuum pump just broke with no warning, it has been replaced and my car still won't start, it's going on 5 months now and they still can't figure out why.

The engine in my 2020 GMC Terrain is consuming oil at an alarming rate, burning through a full supply within one hour of operation. This excessive oil consumption has repeatedly caused significant damage to the coils and spark plugs, rendering them ineffective within 24 hours. The issue has led to multiple cylinder misfires, poor vehicle performance, and a transmission stall, posing a serious safety risk while driving. The GMC mechanic at Jim Ellis Buick GMC diagnosed the problem as internal damage to the pistons, which they state requires a full engine replacement. They also confirmed an internal oil leak within the engine, which is contributing to bad emissions and further degrading vehicle performance. This defect not only compromises the reliability and safety of the vehicle but also raises significant environmental concerns due to the excessive oil burning and emissions. I am requesting a thorough investigation to address this issue and determine whether it is part of a broader manufacturing defect affecting similar vehicles.

No warning, the brake pedal went stiff as a board. No brakes could not stop doing 35 on a residential road. Had to coast to a stop in neutral.

The brake system failed. No warning. When the brakes failed, driver ran the car into a tree to stop instead of hitting pedestrians or other vehicles

Every time it rains, the floorboard of my car is soaking wet. I took it to the dealership, and they stated the leak is coming from inside the firewall. I have only had this vehicle for 2 years and just recently moved to a house without a garage. Now that I am just now noticing it, I am wondering if it was like this when I bought it, but I am only noticing it now that I do not have a garage. They want to charge me over $1,000 just to take apart the dashboard to find the leak and that is just insane. There is no telling how much mold, rust, etc. could be in my car from this leak.

My car sunroof drainage system is not draining properly and GMC won’t see me for a month. There’s an excessive amount of water that’s pooling in the rear passenger floorboards buckets of water.