2019 GMC Terrain Owner Complaints

While driving on an interstate, vehicle became sluggish when accelerating. Took off on exit, engine was reduced to 50% power, attempted to drive to large parking lot, lost brakes, got the vehicle stopped in an intersection, would not shut off, go into neutral. Finally shut off, had to call tow truck, holding up traffic in a busy intersection. Was told it would be just $900 to fully diagnose problem, but it appeared the vacuum pump failed, threw broken metal into engine and now will have to be replaced at my cost. NO advanced warning of any type of problem, no warning lights, etc.

NHTSA ID

11766640

Incident

Sep 21, 2026

The contact owns a 2019 GMC Terrain. The contact stated that after pulling into a parking lot, the vehicle failed to shift into park. The vehicle was towed to a dealer where the contact was informed that three fault codes were found. The dealer informed the contact that the transmission needed to be disassembled for a full diagnostic test. The vehicle was not repaired. The vehicle was scheduled for the transmission to be disassembled for the diagnostic test. The failure mileage was approximately 60,000.

NHTSA ID

11766497

Incident

Sep 22, 2026

Mileage

60,000 mi

On 9/15/2026, my wife drove her car, a 2019 GMC Terrain, to a doctor's appointment. She reported no known issues with the way the car operated during her drive nor had she or I experienced issues prior to this event. After she finished her appointment, she attempted to start her car and was unable to get the car to start. She also noticed that the brake pedal was stiff and hard to depress. When I arrived, I tried to assist her, thinking that an electrical issue was the fault. However, I was still unable to start the car and I had to have it towed after I couldn't start her car. I had it towed to a mechanic who initially thought the car had a bad starter, however, after attempting to manually turn the engine, he found that the engine was completely seized. He also confirmed that the oil in the car appeared to be without fragments in it and that the oil level was adequate for normal operation. This car is only seven years old, has had routine maintenance, and is about 60 miles over 100,000. No prior issues were noticed before this happened. I'm currently waiting on an engine for the car so we can start using it again.

NHTSA ID

11764910

Incident

Sep 15, 2026

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.

NHTSA ID

11762176

Incident

Aug 24, 2026

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.

NHTSA ID

11758661

Incident

Aug 20, 2026

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.

NHTSA ID

11758591

Incident

Aug 15, 2026

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.

NHTSA ID

11757612

Incident

May 20, 2026

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."

NHTSA ID

11755772

Incident

Aug 8, 2026

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.

NHTSA ID

11748359

Incident

Mar 27, 2026

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.

NHTSA ID

11748117

Incident

Jul 3, 2026

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.

NHTSA ID

11743318

Incident

Mar 4, 2026

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?

NHTSA ID

11738911

Incident

Jan 1, 2026

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.

NHTSA ID

11737591

Incident

May 10, 2026

Mileage

76,000 mi

I got into my car to head to the store today. Upon closing drivers door I heard a muffled sounding pop. As I looked around I noticed back windshield looked “weird”. Got out and walked around the back to see it completely shattered. It just exploded and every inch has a crack or chip, even all asking the edges of the glass. I lifted the tail gate to see if a rock was thrown by chance and a chunk fell into the car. No rock was found. It simply shattered. The temp today was low 60’s on May 3rd, 2026 here in Ohio.

NHTSA ID

11735393

Incident

May 3, 2026

My cars breaks failed by a vacuum pump failer and I almost died on the a hill going home

NHTSA ID

11733476

Incident

Nov 26, 2025

ENGINE BREAKDOWN 1.5TURBO IN 11/28/25 WITH 16820 MILES ON IT. IT IS NOT AVAILABLE I HEARD A BANG AND SMOKE OUT OF BACK LOST POWER WHILE DRIVING ON THE HIGH WAY DAMAGE WAS CONFIRMED BUY A DEALER GOODWIN CHEVROLET IN BRUNSWICK ME YES BUY GM DEALER. NO THERE WERE NO WARNING LAMPS OR OTHER SYMPTOMS BEFORE FAILURE. CAR WAS CHECK ON 3/30/2023 AT 10383 MILES FOR SHAKING AND LOSING POWER.CAR DID COME OUT IT TOOK IT TO LEE GM DEALER IN AUBURN ME COULD NOT DUPLICATE PROBLEM.

NHTSA ID

11732575

Incident

Nov 28, 2025

This is the 4th time my vacuum pump has “broke” my brakes become hard and stiff and my brake assist light comes on. It happens EVERY winter when it drops below freezing. This is the second time this winter it has broke and now my check engine light is on. It is not cheap to fix and a major safety issue. Would like to add I was only backing out of my drive way this last time it happened. I was going maybe 5-10 mph.

NHTSA ID

11731108

Incident

Jan 5, 2026

Brake assist light came on and brake pedal became stiff/hard to push. Vehicle struggled to brake. Replaced brake pads and checked brake fluid. Brakes still inoperable. Check engine light came on for vacuum pump. When replacing pump, metal shards and pieces were falling out when original was removed. Once replacement was installed vehicle began hesitating to start and run.

NHTSA ID

11727730

Incident

Mar 24, 2026

My Transmission went out of my truck. I was told this has happened to others of the same make and model, so this is a known issue with this transmission. I was driving down the road and the car completely stopped in moving traffic. I was almost hit by other vehicles and then had to take my truck to get it repaired. I was told it was not able to be rebuilt that it had to be completely replaced. This is radiculitis since this vehicle is not that old and again a known issue. I want to be sure mine was listed as one that had to be repaired in the event a recall is done so that I may get my money back.

NHTSA ID

11726390

Incident

Jul 14, 2025

The contact owns a 2019 GMC Terrain. The contact stated while driving at an undisclosed speed, the transmission unexpectedly shifted into neutral(N). There was transmission fluid on the ground, and the vehicle became disabled. The vehicle was towed to the dealer, where it was diagnosed with a transmission accumulator leak. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 180,400.

NHTSA ID

11724954

Incident

Mar 12, 2026

Mileage

180,400 mi

Vacuum pump exploded into camshaft and engine area, causing me to lose brakes completely on the highway. Costly repairs to clear out metal shrapnel and replace camshaft.

NHTSA ID

11724591

Incident

Mar 10, 2026

The backup camera in our 2019 GMC Terrain stopped working one day - has blue screen and says Service Rear Vision System - so we’ve been driving a year with no backup camera. The dealership wants almost $1000 to fix this issue. And this issue seems to be very common in 2018-2020 Terrains. We bought the vehicle in December 2023

NHTSA ID

11722084

Incident

Mar 1, 2025

I am driving a 2019 GMC Terrain SLT, and I have a serious concern regarding a recent service experience. On 02/10/2026, I had an oil change and a complete vehicle inspection performed at Kunes GMC Greenfield, Wisconsin. After the service was completed and I returned home, I noticed an unusual noise coming from under the engine hood. I immediately went back to the dealership and informed them of the issue. I was asked to return the following day (02/11) for further inspection. After their investigation, I was informed that the vacuum booster had failed. It appears that this issue was not identified during the original inspection, and I was the one who brought the noise to their attention. From my understanding, vacuum pump/booster issues are common with many 2019 GMC Terrain models. I am surprised that this has not resulted in a recall, especially considering the potential safety risks it poses to me and my family. What concerns me even more is that this issue was not detected during the dealership’s inspection. If it had worsened, it could have led to a serious safety situation. I had to spend $450 today to repair what appears to be a manufacturing-related defect. I respectfully request that this matter be escalated and that my claim for reimbursement be reviewed. I would appreciate your assistance in helping me pursue compensation for this expense.

NHTSA ID

11717369

Incident

Feb 11, 2026

My family and I were returning home from vacation in another state, and while we were driving on the interstate, an alarm popped up on the DTC stating ruduced engine power. I tried to start slowing down so I could take the next off ramp and could not push the brake pedal in. I had absolutely no brakes trying to slow down from interstate speed. I was able to pull into a gas station parking lot while avoiding other vehicles. I was very lucky not to get in an accident. I had to have it towed to the nearest service center and was charged nearly $4000 for repair. The car has not ran right since we recieved it back. I called them back to let them know and was told the only way I would not have to pay to have it looked at was to bring it back to them. That shop was four and a half hours away from my house. The car was less than twenty miles out of the warranty when it broke down (nine miles to be exact), then they lied on the the paperwork and put the milage after they test drove it.

NHTSA ID

11715704

Incident

Jul 5, 2024

Vehicle was started for the second time that day on 1/5/26 and the engine light was on. I drove the vehicle to an auto parts store to have them check it with an OBD-II scanner. It had code P050F. I had no idea how serious this issue could be at the time. I made an appt with the GMC dealership and dropped it off the evening of 1/6/26. They said there was a software anomaly in the engine control module and needed to be reprogrammed. I paid the $200 diagnostic fee for them to reprogram it. I learned that this anomaly could have caused my brakes to not work while driving it. I had been driving the vehicle back and forth to work until I dropped it off. This issue could have caused serious harm or death to myself and others. While researching online, I've seen that other vehicles have had safety recalls and additional warranties added for these issues, but my vehicle isn't included in this.

NHTSA ID

11710765

Incident

Jan 5, 2026