The contact owns a 2018 GMC Terrain. The contact stated while driving 40-45 MPH, the vehicle started coasting and stopped unintendedly. The contact stated that the vehicle drove for a while and then coasted and stopped. The message that the -??Engine Power Reduced-?? was displayed. The contact stated that the brake system warning light was also illuminated. The vehicle was towed to an independent mechanic who determined that the camshaft had disintegrated into the engine. The mechanic informed the contact the vehicle was unrepairable. The vehicle was not repaired. The local dealer was not contacted. The manufacturer was not made aware of the issue. The failure mileage was approximately 60,000.

- Lake Orion, MI, USA

I got my car out of the shop a week ago for my brakes the car was in the shop for a month and this past weekend my car is doing the same exact thing a week later I was on I 75 also hit a semi truck

- Vienna, GA, USA

The contact owns a 2018 GMC Terrain. The contact stated that while driving at an undisclosed speed, the vehicle stalled. There was no warning light illuminated. The vehicle was restarted; however, the failure recurred. The vehicle was taken to an independent mechanic where it was diagnosed that the vacuum pump had failed and needed to be replaced. The vehicle was not repaired. The vehicle was taken to the dealer where it was diagnosed that the vacuum pump had failed and needed to be replaced. The vehicle was repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 121,000.

- Beaumont, TX, USA

While driving the vehicle the vacuum pump failed and caused the camshaft to seize and physically break which caused the break peddle to become hard and breaking the vehicle was limited and almost nonexistent, which caused an extremely dangerous situation on the highway.

- Wayne, PA, USA

The contact owns a 2018 GMC Terrain. The contact stated that while her husband was driving 30 MPH, the message "Engine Power Reduced" was displayed and the vehicle stalled. The vehicle was not able to be restarted. The contact stated that the vehicle was coasted off to the side of road. The vehicle was towed to the residence and then to a dealer where it was diagnosed and determined that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 92,000.

- Morse, LA, USA

In 2022 and now in sept of 2024 my entire braking system has failed. Cause you a complete in abilty to stop the vehicle. Upon this failure without any warning peice of the braking system connected to the engine shoots shrapnel into my engine and causes the cam to be destroyed. Now I can't get my car back because of a shortage on this part.

- Alliance , OH, USA

The contact owns a 2018 GMC Terrain. The contact stated while driving 45-50 MPH, a message indicating that the engine was not at full capacity was displayed. The vehicle was taken to the dealer, where it was diagnosed that the engine had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 342,000.

- Orangeburg, SC, USA

The vacuum pump gears for the brake assist was shattered and metal parts were sent into the engine. I lost power brakes and was lucky to be able to stop the suv. The car was towed to a GMC dealer where it was diagnosed with a damaged exhaust cam, a shattered vacuum pump and metal pieces in the motor. Cost to fix $3200. This is a 2018 GMC Terrain with 112000 miles on it. I had a powertrane plus warrenty that was still valid but they refused to pay for anything. They claimed the vacuum pump caused the problem and it was not the engines fault. There were no warning check engine lights before this happened.

- Levittown, PA, USA

The car very suddenly went into a reduced engine power mode, with check engine light and was immediately parked. Figuring I could turn the car off and turn it back on, however it sputtered turning off and shook violently before I was able to turn it off. It would then not turn back over, so I left it off and had a tow truck drive it to a GMC mechanic. The GMC mechanic was unable to diagnose an issue after days. I then had it towed to another local mechanic who stated the parts were "junk" and the engine needed to be replaced. Engine codes were related to the camshaft sensor and brake booster. It is my understanding the vacuum pump broke off into pieces, went into and destroyed my engine.

- Southington, CT, USA

While driving on the interstate the brakes all the sudden stopped working. I was able to stop the vehicle by pulling over to the shoulder of the road. I received a warning saying service brake assist and a check engine light after the brakes went out. The vehicle later shut off and is no start with no warning codes. I am currently towing the vehicle to a mechanic. Several people claim to have the same issue online stating that it is an issue with the brake vacuum booster shearing off in the exhaust cam which then causes major damage to the engine. It appears the same issue exists with several other GMC models that were already recalled

- Ocala, FL, USA

While driving the vehicle which only has 68,000 miles the reduced engine power warning light appeared. As quickly as was safe the car was pulled to the shoulder. It was towed to the dealer who states the Vacuum pump seized causing the camshaft phase actuator locating pin to spin. Originally they stated a new camshaft and vacuum pump were needed at $3,500, but now state the entire engine is damaged and must be replaced at cost of $12,000. The vehicle was well serviced and this manufacturing flaw lead to the vehicle be stopped on the road putting both the occupants and others around at risk.

- Ontario, CA, USA

Rear side windows in hatch area leaked filled up spare tire compartment with about 3-4 gallons of water. Now navigation doesn't want to work, sunroof not working, electric systems are not working right

- Willits, CA, USA

The 2018 GMC Terrain has the AutoStop feature but does not incorporate a switch to defeat AutoStop. In heavy stop and go traffic or when fast acceleration from stop is required, the response of the engine in having to restart creates not only a nuisance condition but a severe accident hazard. It not only hesitates from stopped, it lurches forward after hesitating, which could cause a collision with a vehicle in front. I have had several other vehicles equipped with AutoStop, and all of them have a defeat or cancel AutoStop switch to allow the operator the opportunity to turn AutoStop Off. My 2018 Terrain Denali is now on its third battery. Having a dead battery in traffic also constitutes a safety hazard as does the inherent danger of using jumper cables. I have asked my dealer for a way to defeat the faulty feature, but they either cannot or will not do it. There must be a software code to easily allow this that the dealer can perform or a slight hardware modification to allow the operator to defeat AutoStop when it creates a safety hazard.

- Magnolia, TX, USA

Driving 2,5 hrs from Binghamton, NY towards Long Island on Saturday. We took a short break and after that I got onto the highway and not even hit the 50 miles/hour speed I received -??engine power reduce-?? alert on the dashboard and car stalled. I was able to pull the car off the road. I was provided a tow truck by the state police and moved to closest GMC service, GRAND PR?ZE GMC Nanuet, NY. This car has only 30,309 miles and it-??s 2018. The car has been fixed by replacing 5 parts, oxygen sensor, pcv tube, air inlet tube etc. We ended up paying $1,460 just before the Holidays. Rightfully, we are very upset with this unexpected event driving a basically brand new car, in 30000 miles. This car has been mostly driven by my wife who is in 60s in local streets not exposed to harsh enviroments. There is a recall I noticed online for 2019 models and almost from the same area of throttle body, but nothing for 2018. Now, my wife and I hesitating to drive the car. Are we going to get stuck on the road again?

- Lindenhurst, NY, USA

There is an has been an issue with my electrical system says I purchased this car in 2017. Myself believe that the issues have not been documented until 2020. When my racy begins to run out, my engine light has been coming on and I-??ve been getting the same code P1101 I took my vehicle to GMC and they told me that the engine light came on because the tape came loose. I brought this vehicle and there-??s no way there should be no tape on it. The service tech also told me that if the problem continue to bring it back and I will have to pay $120 or whatever the label rate was for them to research I contacted GMC to file a complaint and I received the whole bunch of calls from a guy named Kevin. I believe he told me that he had been contacting [XXX] and no one returned his call and that he was sorry he couldn-??t help me. This is my report number one of them from GMC. [XXX]. Everywhere I take my car they tell me that they have a lot of customers with the same issue and they tried to replace what the code is matching which is the mass airflow sensor but that does not help there is some type of problem with the engine or the electrical system with this vehicle. I am not the only consumer that has had this problem. I don-??t know what to do. I have two kids I cannot afford to keep pay and label rate for them not to find the problem. I am also attaching the typical email that GMC sent out when they are working with the dealerships because I have been in contact with them and the person that was calling and then they sent me this email. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Chicago, IL, USA

Last year this time brakes went out at 50 mph power brake module imploded from inside out. The part was on national back order. Second incident car stopped immediately while traveling 40 mph no warnings or anything both incidents could of been horrible. Not sure on second incident the issue yet car is in shop. Both incidents are safety concerns for myself and others. Driving at average speeds and something malfunctioning is a great concern of mine. I contacted GMC no one to talk too just chat and the person on the other side told me it was no concern of theirs all was dumbfounded by the conversation but until I said I was putting on social media and bringing to everyone attention her entire tune changed in regards to part and service. So I researched locally and luckily I found the part they had one left and I was told by dealer that it is an issue on these vehicles. Both safety incidents have been within a year of each other 2022 and 2023

- Georgetown, OH, USA

The vacuum pump started leaking and the car was parked immediately. When The pump was pulled out to be replaced, the reason for the leak was identified. The vacuum pump had busted into small pieces which are now in the engine.

- Point Pleasant , WV, USA

Catalytic converter went out at 101,650 miles and the dealer has no replacement part. This is the diesel engine, almost every other year was recalled and they extended the warranty to 100,000 miles. And they stopped making this engine. Seems like they should at the least have a replacement part for a car 5 1/2 years old. They also said the 2017 were recalled, this vehicle was built Jan 2018. The vehicle currently will only go 5 MPH so it cant be driven. There was no warning of the failure.

- Oak Hills, CA, USA

In mid traffic my 2018 GMC terrain just stopped with no warning, no check engine lights, no smoke from the vehicle, nothing. I was in Charlotte traffic, driving, with my family in the vehicle, the car stopped right in the middle of driving, and I had to quickly and sharply turn the wheel to got into a median to avoid hitting the car in front of me and avoid being rear-ended. The dealership informed me that the vacuum pump in the engine cracked (broke) causing another part in the engine to malfunction. There were no, none, warning lamps, messages, or other symptoms prior to this incident that would of indicated a problem so that I can proactively service the vehicle and keep my family safe.

- Belmont, NC, USA

I was driving my vehicle, there was no indication that the vehicle was in need of servicing or that something was wrong with the vehicle, no check engine lights were on. The vehicle stopped in mid traffic, just completely shut down in active traffic. I had to serve my vehicle in to the curb/median to stop if from hitting traffic ahead of me.

- Belmont, NC, USA