2019 GMC TERRAIN Complaints

While driving my 2019 GMC Terrain with three children as passengers, the vehicle developed a braking/engine problem. The brake pedal became very hard, and the vehicle subsequently became undrivable and would not start. I received no advance warning through the GMC app indicating that the vacuum pump was failing. The vehicle was towed to a GMC dealership. The dealership diagnosed a failed vacuum pump and advised that the engine requires replacement, with an estimate of approximately $11,238. I purchased this vehicle new. I am very concerned that a vacuum-pump failure can result in reduced brake assist/increased brake-pedal effort and major engine damage without adequate advance warning. Three children were in the vehicle when this occurred, and the sudden change in braking created a serious safety concern for everyone in the vehicle. The vehicle is currently at the GMC dealership. I have requested that relevant parts be preserved and am requesting GM Policy Assistance with the repair.

This is the second time I have noticed storm heavy rain that my car is taken on water. We had an extremely heavy rain in June and no windows was left open. I did not know water had gotten into my car for an entire month when I heard a solution sale when I came to a break, what I did realize is that there was condensation buildup is inside of my car, but it was not sure why. After searching, I was able to locate and discover thatI had at least 3 inches of water standing water in my spare tire, section of my trunk. There was also an extreme amount of water on my floors in the back row once I took out my mats, I found there to be mold back there.Still unsure of how t the water got into the car I used my shop vac to suck out the water. We just had an extreme amount of heavy rain again. We are now in August. We just had extremely heavy amounts of rain and once again there’s water in the well trunk of my car where the spare tire is. I actually made sure to sit outside in my car during this heavy rain storm to see where the water was coming from. It appears that the water is coming from the sunroof, which then leaks to the back on the right hand side where the outlet socket is. I watched it dripped down into the back of the trunk into the spare tire well. I do not understand why this issue has not triggered a a recall yet as I’m noticing this is not just with my car. This is apparently the sixth or seventh car that has experienced this issue and GMC has yet to do a recall on it. This is very alarming and concerning God forbid I’m driving to work or I have one of my children in the car during a heavy rain storm and it hits the electrical wires or electrical panel with something else bad happens.

On Saturday, August 15th we were driving on the freeway when with no warning the check engine light came on and the vehicle began to run poorly, and then the vehicle lost electrical power and it became difficult to steer and the brake pedal became stiff, making it difficult to stop and pull over. The vehicle would not start on command but kept running very poorly, it also became impossible to shut the vehicle off until it seized. It was later towed to a local repair shop, and today, Friday August 21st the shop confirmed that the vacuum pump on the brake assist failed and it would need a total engine replacement.

The car’s brakes hardened on the highway, posing a life-threatening danger, right before the engine died. Following a tow to the dealership’s service center, an initial inspection revealed a broken vacuum pump and broken camshaft. The dealership stated that there was evidence that camshaft debris may be scattered throughout the engine. No further inspection has been done at this time due to the probability of major engine damage and/or potential repairs.

While driving my 2019 GMC Terrain on local roads, the vehicle suffered a sudden and complete failure of the braking system. The brake pedal became extremely hard to press, and the dashboard displayed a critical error message stating 'Engine Power is Reduced.' during this frightening safety incident i felt lucky to bring the car to a stop without an accident. The vehicle had to be flatbed towed to a repair facility. This sudden loss of power braking is a known, documented defect matching the engine-driven brake vacuum pump failures currently subject to federal class-action litigation (Thieme v. General Motors). I am requesting a formal safety investigation into why the GMC Terrain was excluded from previous GM vacuum pump recalls despite posing an identical, life-threatening risk to occupants."

While driving the vehicle became extremely difficult to stop I was advised that the Vacuum booster pump was broken and it needed to be replaced. This was first completed 09/24/25 by Gateway tire and service center. I was advised that there was a service bulletin for the issue. Then I have had the same thing happen and I returned the vehicle to the same repair shop and I was advised that the Vacuum booster pump was broken and it caused the exhaust camshaft to break, as well as the timing was out. The shop had to replace several things in order to repair and I was responsible for the cost. There was no warning before either of the incidents.

No engine lights are on. When at stops it starts chugging and when I accelerate sometimes it does not go like it should. It idles high and feels like it is slipping. I have almost been hit in the rear several times when this happens. One lady did rear end me but the damage was so little that I did not call the cops. This vehicle has not been inspected and it is available for inspection at any time.

The turbo went completely out at around 105k miles while I was driving to work. I had to coast into a repair shop because it was smoking and wouldn’t go over 20mph and then have it towed to the place that repaired it. Since then, the transmission is having trouble shifting gears. The car struggles to accelerate and I have to go abnormally slow after coming to a complete stop in order for the car to get into gear. The onstar diagnostic says everything is fine but it is clearly not fine.

My 2019 GMC Terrain has a faulty back up camera system. It shows a blue screen that says Service rear view camera system, This has been a faulty system for years until it finally stopped working completely. I have researched the issue and have discovered this is a known problem. There was a Service Bulletin 19-NA-076 dated April of 2019. Why has there not been a recall for this safety issue?

The contact owns a 2019 GMC Terrain. The contact stated that while stopped and attempting to turn to exit a highway ramp, he observed a loud banging noise emanating from the engine compartment. An "engine reduced power" message appeared. The vehicle then went into limp mode, and when the brake pedal was depressed, it was stiff as a rock. The vehicle coasted while he continued attempting to depress the brake pedal, and it eventually slowed down. The vehicle was steered to the side of the road and turned off. When the vehicle was turned back on and he attempted to depress the accelerator pedal, the vehicle did not accelerate. The vehicle was taken to his mother's residence approximately 100 miles away in limp mode and parked. The vehicle was not diagnosed or repaired. The contact stated that his brother, during an inspection of the vehicle, removed the vacuum pump and noticed that it was broken with numerous pieces that had gone into the engine. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 76,000.