2018 GMC Terrain complaints

Car is losing go power when accelerating on to interstate. It’s like the transmission loses power, the d illuminates, and then it kicks in to drive. It puts us at risk for an accident and I had a semi almost hit me because of this. This has been reproduced at the mechanic shop as well. No warnings before this happens

My vehicle put itself in park in the middle of an intersection while waiting to make a left turn in the middle of rush hour traffic. The car could not even be placed in neutral to be pushed out of the way of oncoming traffic. Narrowly avoided a collision.

On 9/3/23 I was travelling down interstate 94 in Illinois when all of a sudden my check engine light came on. Not knowing what the issue was, but knowing that the car still seemed to be OK and I was only a few miles from home I decided to drive home and figure out the issue from there. At this point I had no idea that the brakes had completely locked up. Once I realized what was happening I did my best to slow the vehicle down by decelerating, frantically pumping on the locked up brakes, and then finally slowing enough to take an exit and roll in to a gas station. Frankly, it was the most terrifying moment of my life travelling 70 MPH without the ability to stop. Upon inspection, the independent service tech informed us that the vacuum pump had exploded (yes, exploded) and that he had never seen anything like it, especially in a car with less than 70,000 miles. What component or system failed or malfunctioned, and is it available for inspection upon request? The vacuum pump failed and unfortunately it completely exploded so there were only a few pieces left inside of the engine. How was your safety or the safety of others put at risk? My brakes locked up completely on the interstate, with my family in the car, and I was unable to stop. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. The independent service center where I currently have the vehicle has confirmed, and spoken with GM. Has the vehicle or component been inspected by the

The contact owns a 2018 GMC Terrain. The contact stated while driving approximately 30 MPH, the vehicle decelerated and failed to accelerate over 25 MPH while the accelerator pedal was depressed. The contact stated that a message was displayed on the instrument panel to “Continuously Drive Vehicle Above 30 MPH”. The contact stated that after the vehicle decelerated into engine power mode, the check engine warning light illuminated. The vehicle was taken to the dealer where it was diagnosed that the Diesel Particulate Filter (DPF) failed and needed to be replaced. Additionally, the contact stated that the vehicle was taken to the dealer twice where it was diagnosed that the Diesel Particulate Filter (DPF) needed to be unclogged. The vehicle was repaired; however, the failure recurred. The vehicle was not repaired. The manufacturer was notified of the failure and the contact was informed to contact the warranty company, but no further assistance was provided. The failure mileage was approximately 110,696.

Driving on highway and all of a sudden I could not break - the car breaks failed to operate - had to slowdown by it self and pull to a McDonalds, I had the loss of effective braking with no warning whatsoever. We found out that the Break Booster Pump was destroyed without any warning from the electronics of the SUV.

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

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.

Transmission failed. Unable to purchase a replacement as there are no available transmissions for this year terrian.

My husband and son were involved in an almost fatal accident on 07/08/23 in our 2018 Terrain. My husband described that the vehicle spontaneously veered to the right uncontrollably, he was unable to steer to correct the vehicle, unable to brake, they went airborne, hit several poles and a transformer, rolled and flipped several times. All the airbags deployed.After the accident, I found a recall notice from back in 2017, I believe, regarding the drive train. My husband was extricated from the vehicle. My son wasble to cut the seatbelt and crawl out the window. From what my husband explained (he was the driver), this sounds like what they experienced during the collision. I never received a recall letter from GM as this is something I would of taken care of and have got repaired. Please see the photos and the recall I found. Please let me know if there is anyone else I need to contact regarsing this collision.My car was almost paid off. My husband and son could of lost their life. Please advise. Thank you!

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.

The contact owns a 2018 GMC Terrain. The contact stated while driving 45 MPH, the check engine warning light illuminated. The contact stated while making a left turn the brake pedal was depressed but failed to stop the vehicle. The contact was able to continue driving without proper braking response to her residence. The contact stated she used the parking brake to fully stop the vehicle. The contact's husband took the vehicle to the local dealer, where it was diagnosed with needing an unknown pipe and vacuum pump to be replaced. The vehicle was not repaired. The manufacturer had not been informed of the failure. The failure mileage was approximately 79,000.

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.

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.

Driving home from our local town 4/15/2023, the brake pedal became to hard to push down. Check engine light came on as I got to my driveway, and that is 1 mile from the main road. My kids were scared to tears as was my girlfriend. Run a scan and dtc p0557. Come to find the vacuum pump on the top drivers side of motor is the part that is bad it broke inside the valve cover. Looking up the issue and find out it is a known problem and no recall. I have kept the parts and all receipts for the repairs, I have to do myself cause the repairs are way to much for me to pay out of pocket. This is a serious issue for this car and year and GMC needs to address the issue. Why has nothing been done yet??? I am making payments on this car with no warranty for the car so I'm stuck fixing the car. But GMC knows that this is a problem and does nothing?!? I remember when American cars were good cars what happened to that time ?? And what happened to company's being responsible for the product they put out to customers? Guess that time is gone, I won't buy another American car again, unless it's a old Detroit built car.

The contact owns a 2018 GMC Terrain. The contact stated that the air bag warning light was illuminated. Additionally, the service restraint system message was displayed on the instrument panel. The vehicle was taken to the dealer to be diagnosed. The contact stated that the driver’s side front impact sensor had failed and needed to be replaced. The vehicle had not been repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 55,705. The contact stated that the dealership suggested that the issue be addressed right away since it involves the airbags.

Temperature sensor for the engine went out...which now affects my remote start not to work

I was coming to a stop with my vehicle and the brakes would not work. I carefully got my car home and to a shop. It was determined that the break booster pump broke which caused metal parts to go into the engine. Now my engine is blown! Bought my car brand new in 2018 and kept up with regular vehicle maintenance has 90k miles.

I was driving at night with my daughter on a two lane highway with no traffic. There was a sound like a gun shot or explosion in the cabin of the car. My panoramic moonroof literally exploded. The glass shattered but did not fall into the cabin. Had the glass fallen into the cabin it could have cut or blinded us or caused an accident as we were traveling at a high rate of speed. No indicators went off as the moonroof has no such indicator. We pulled over to inspect the damage and immediately saw the glass damage. I have contacted insurance for repair. Upon research it seems that this is quite common for vehicles but not enough for any type of recall or service bulletin.

The dealer has not been very familiar with the diesel option in this vehicle. Dealer has found nothing wrong with the engine in this regard. Now the car is out of warranty and will be very expensive to fix according to outside mechanics. The car is experiencing severe BLOW-BY When the oil filler cap is removed while the engine is running, the pressure coming out of the engine is very high. I understand this is a very bad thing to be happening. The car has an engine light on, and it will not go out.

While driving in the rain at about 25-30 mph I noticed a loss of propulsion and before I could turn off the main road the vehicle came to a rolling stop and would not recognize any gears. causing us to block the roadway and had to have it towed home. Took to local car dealer they said it RDCCM abnormal errors like u0422-00 and brake control module errors. Further diagnostics were need to figure out the cause and it possible that the Transmision is having problems now! This should be recalled.

Camshaft failed during driving causing vehicle to become disabled in the roadway and almost hit many times. The camshaft is being repaired by ase certified mechanic at an independent service center. A reduced power notice cam on a few minutes prior to the failure.

Brakes go to floor an brake peddle starts to vibrate, (lost of brakes ) Brake assist light comes on. Vehicle has 27000 miles . Problem started at 6000 miles an was brought to GMC service centers 3 times for same issue. They replaced 3 different parts at a total cost of1600 dollars. Brake system is being replaced one part at a time at my expense, GMC has no clue what problem is. Will not admit there is an issue? Just got vehicle back for 3rd time an 3rd new part .

When driving the car at low speeds, or right after having been stopped for a few moments. Upon, acceleration, the car will sometimes go into a limp mode. On the DIC, will be displayed a warning about how the car will have the speed reduced after 175 miles and to check the emissions system. The speed has already been reduced at that point. Also displayed maybe a warning about how the power has been reduced. USUALLY, if I turn off the car and wait about a minute, I can restart the car and drive at a normal highway speed again. But not always. The warning on the DIC, will usually turn off if the car does return to normal speeds after about 5 - 10 miles. However, the check engine light may still stay on for several days. This problem can be a daily occurrence. I've had the car in the shop several times, and they have been unable to fix the problem. The car can be unpredictably unsafe, when speed is instantly reduced to 30 mph!

The contact owns a 2018 GMC Terrain. The contact stated while driving at various speeds, the brakes became inoperable. While the vehicle was in park(P), the gear shifter inadvertently shifted into an unintended gear. The brake assist warning light was flashing. The vehicle was taken to the local dealer where it was diagnosed that the vacuum pump and brake booster needed to be replaced. The vehicle was repaired four times but the failure persisted. The manufacturer was contacted and informed the contact to take the vehicle to a local dealer if the failure recurred. There was no additional assistance provided. The approximate failure mileage was 131,000.

Vehicle stuck in emergency assist mood. Without warning I couldn't slow down/stop without putting alot of my weight on the brake breaks were so hard to press down.

When trying to brake, brake pedal became extremely hard to push and Repair brake assist notification and check engine light came on

Vacuum pump went out brakes hard to push and I know gmc had a recall for this issue on other vehicles as well previously.

Brake has to be pushed all the way down HARD to stop, brake assist warning comes up. I’ve had the car for less than 2 years and it’s way too new for anything to go out. Undriveable unless it’s fixed.

The Safety Restraint System warning keeps coming on and off as well as the air bag light. It happened months ago so I took it in and got it looked at and scanned. All the seatbelts were checked and the scan came back with nothing. Then it stopped for a couple months and now it has started again. Ive had 14 surgeries in the last little less than 4 years and I'm about to go into my 3rd back surgery since November. I cannot get into an accident and not have airbags as I've also had brain surgery 3 winters ago as well. I am disabled and do not have a ton of money either for fixes that aren't necessary but this safety issue is crucial to me. I see that many 2018s have been recalled for the exact same issue that I'm having however mine doesn't come up with that but it is happening to me so that should be included. I also need some direction if not as to why this is happening because I cannot afford to have a dealership, no less, replace every tiny little thing looking for the culprit at $150 an hour when I live on $1,200 a month and most goes to medical. Please advise on what to to or where to start. Thank you.

While getting off the interstate, the brakes failed with no prior warning, or issues. The brake pedal became extremely difficult to depress and stopping distance was greatly increased. Could not come to a complete stop without using the emergency brake. We drove home (about 2 miles from the interstate exit) and about a half mile after the brake failure, a "service brake assist" light illuminated. Vehicle was towed to dealership the next morning. The problem was the vacuum pump exploded and caused vacuum to the brake booster to be lost, making the pedal difficult to push. Luckily this happened at 11pm and there was nobody in front of us, there definitely would have been a collision.

At ignition, vehicle tire pressure monitoring system indicated low tire pressure in rear right wheel of 9psi; right front tire indicated 38psi and left front and rear indicated 38psi. Driver verified pressure as good at 38psi in rear right tire with hand held gauge. While operating the vehicle on the interstate, vehicle driver experience a flat tire in the right front passenger tire. Tire Pressure monitoring system indicated 41psi in right front tire (even while flat), and indicated right rear tire at 0psi even though it was visually inflated.

I have a 2018 GMC TERRAIN which I bought brand new from General Motors. In May 2022, the vehicle started jerking/hoping and trying to stall when the speed gets to 55 miles per hour or higher. I have taken it to the dealership on three different occasions for repair and I still have this issue. General Motors engineers were involved in every step of the repairs. They just do not know what is going on with the car or fix it and they are too stubborn. The dealership told me today that they cannot do anything else to the car. They also said they had a code from the engine last week and General Motors said they do not know what that code means. They are forcing me to accept/drive the car in this unsafe condition. I have contacted them multiple times and they do not care.

Radio, hands free calling, and light on mirror shorting out. None of them work. It’s like it has a short in the wiring.

6/3/22 I went to the grocery store which is on a four lane road. When I left the store I had no brakes. On a four lane stop and go road. The was no warning just nothing peddle to the floor and now check engine light is on. I am reading this same problem repeatedly. I love this car but this is a serious hazard and needs to be addressed. We are all driving around practically rear ending people. I was an inch from the guy in front of me thank God the light changed as I was coming up on him or I would have hit him.

I was driving out of town (2 hrs from home) with my 2 small children and my mother, when I tried to slow to come to a stop my breaks did not work and I almost rear ended someone. It was sudden, there were no signs that my breaks were going to mess up. When I tried to look up recalls, there were none for my vehicle BUT there were MANY statements of people who drove gmc or gm vehicles that had the same issue with the vacuum boost for the brakes around 50k miles where the breaks just quit or were hard to use. It seems to be a common issue and is VERY unsafe. I cannot afford to fix the issue and I don't feel as though I should have to if other terrains have been recalled, except mine which I do not understand.

Started car in parking lot. Warning came on saying “service safety restraint system” and airbag illumination was on. Just notified salesman as I have only had this vehicle about 10 days. Bought it used. Unfortunately.

My driver seat does not raise or incline so it gives me like a visibility when I’m driving. The seat needs to be raised so I have more visibility on the road while I’m driving.

When you're sitting at idle in gear and go to accelerate the transmission will slip out of gear into neutral then into gear after the rpms climb. This happens alot. According to the dealership this is normal based on information from a bulletin from GMC.

Unknown

1. 2018 Terrain would not start in a parking lot. Remote was used after several attempts to start with push button failed, and after a slight hesitation , engine started. Vehicle was driven about 6 miles without incident. 2. Vehicle was driven about 10 miles the next day and start/stop engaged at a stop light but would not restart. After about 3 minutes of cycling throught the starting procedure, the vehicle started. Drove another 8 miles without incident. 3. Next morning, drove about 3 miles to intersection where start/stop engaged but would not restart. After about 30 minutes of cycling through starting procedure and an attempt to jump start was made the vehicle restarted. At this point, the vehicle was taken to Romain GMC for service. A new battery was installed and other related operations.After about 10-15 miles, the vehicle would not start. Remote was attempted but it would not start. After about an hour, vehicle started and was driven back to Romain avoiding the stop/ start engagement.

The contact owns a 2018 GMC Terrain. The contact stated that while driving, the seat belt restraint warning light illuminated continuously while the driver’s and passenger’s seat belts were fastened. The dealer was informed of the failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 21,700.

The contact owns a 2018 GMC Terrain. The contact stated that while her husband was driving 50 MPH, the brake pedal was depressed and went to the floorboard. The service brake assist warning light was illuminated. The vehicle was not taken to a dealer nor independent mechanic to be diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 69,000.

The brakes are extremely hard to engage while driving. All 4 rotors are pitted with less than 30k miles. Doing some online research this is a common problem and should be addressed. I just did my first set of brakes at 100,000 miles on my truck.

11/24/2021 buy 2018 GMC Terrain, before leaving the dealership I told the seller that the engine light was on he said it was because they removed the alarm which I didn’t want to buy and the light was going to be off later and told me to take the car to service on Monday 11/29 so my husband took the car they repair a detail on the handle door and he said the engine light it’s off so we tough what he said about the alarma, we trust the seller but on 12/26/2021 I left California to Texas, I was about 4 and a half hours away the car began to lose speed and a very strange noise was heard, I stepped on the accelerator and did not raise speed, I had to step aside the freeway and the car turn on but It did not go forward or backward and NO warning light was on dashboard, nothin ! The car broke down in Arizona in the middle of nowhere, it’s was freezing and almost got hit by a semi truck, it was a very frustrated experience.

Catalytic converter failed when driving damaging the engine. Vehicle undrivable and waited for repair at shop for over 90 days. Engine warning light keeps coming on with error code P1186 that the GMC dealer can not fix.

Beaverton GMC did repair work on my vehicle. During the inspection they said they found the radiator leaking from a number of spots and it needed replaced. It has never leaked and did not need replaced. Why did they do it? I as for the parts but they tossed them and would not give them to me.

Auto-Stop feature does not have a button to disable the feature.2019 model has the disable feature and GM needs to provide a means to disable it, even if on a temporary basis.

Multiple warning lights are appearing at once (Automatic brake assist, forward collision assist, parking brake released) When the car is put in reverse, the radio turns off for a brief moment and the steering assist warning shows on the dash. The steering wheel snatches back in the opposite direction causing a safety concern. The car also completely cuts off after the auto-stop takes effect at red lights causing me to have to pump the brakes at least twice to re-ignite and be able to accelerate.

Car gives a "Power Steering Reduced, Drive With Care" message after turning the wheel one direction and braking simultaneously. After message is displayed, power steering is no longer available, and this can happen while driving around a curve. Once car is powered off for longer than 1 minute, can turn back on with no problem, but problem can come back just the same. Took to GMC dealer. They recalibrated my car, but problem came back 1 month later. They said they can replace the whole electric steering system, but that may not fix the problem, as they do not know what the real problem is. Vehicle was purchased used with 50K miles.

The vehicle experienced a sudden loss of braking and displayed a “brake assist “ fault message. The check engine light has illuminated. The sudden loss of braking was in a residential neighborhood traveling at 35 mph. I was turning during the loss of braking and was able to narrowly avoid collision with the cars at the intersection because I could not slow to a safe speed. The fault codes have not been read by the dealership yet nor has the repair been completed.