2020 GMC TERRAIN Complaints

View complaints related to 2020 GMC TERRAIN. The complaints found here are submitted by actual consumers with first hand experience. There are more than 190 complaints submitted for the 2020 GMC TERRAIN. You can submit your own complaint to the NHTSA or call the Hotline, Monday-Friday 8am to 8pm at (888) 327-4236, TTY: (800) 424-9153.

  • 2020 GMC TERRAIN
    - San Antonio, TX

    The vehicle is a 2020 and should not already be having electrical issues. The vehicle repair is over 5k for needing a starter motor, water pump and drive belt. A starter should last up to 100k miles and water pump should last 10 years not 4. This vehicle is a lemon and should not have so many issues.

    Source: NHTSA WEB SITE
  • 2020 GMC TERRAIN
    - Jacksonville , FL

    Incident happened August 9, 2020. Brakes suddenly stiffened and unable to stop vehicle. There were no warning signs or indicators. Thank goodness I was going at a lower speed and was able to coast into an area to stop. Ended up being the vacuum pump. This needs to be recalled ASAP. This could have been a fatal accident. I have kept the old vacuum pump as well as the pieces that were thrown from it that the mechanic had to dig out.

    Source: NHTSA WEB SITE
  • 2020 GMC TERRAIN
    - Brockport, NY

    The vacuum pump locked up and sheered off the end of the cam shaft and made the cam skip timing and destroyed the motor. While driving no check engine likes till after i lost power. Luckly i was able to roll to a stop The pumps have been a problem the car is only 4yrs old and has 71000 miles.

    Source: NHTSA WEB SITE
  • 2020 GMC TERRAIN
    - Baltimore , MD

    As I was driving, brakes became very hard to press. I was barely able to slow down to bring the car to a complete stop. Brakes became very stiff and required a ton of force to come to a complete stop. This came with no warning signs or alerts from vehicle. It was only after this occurred that the Service Break Assist light came on.

    Source: NHTSA WEB SITE
  • 2020 GMC TERRAIN
    - Cleveland, GA

    On Wednesday, June 26, 2024 my 2020 gmc terrain unexpectedly malfunctioned and failed to restart. The engine light came on and I attempted to restart it for nearly 2 hours with no success. Fortunately, it finally started and once I got it home my fiancé plugged the car up to the code reader. P129F “Manufacturer Control” were the results. After further researching, this is for the fuel pump/fuel pump control modular assembly. In January 2023, NHTSA released a notice for my exact vehicle for this very scenario I experienced. And as of June 6th, 2024 a class action lawsuit was filed against gmc for this issue as well. My vehicle is not able to be repaired due to 1) my vin not being included on the recall list and 2) all the parts that were in inventory are also deemed unsafe due to the lawsuit documents shared online and this has caused a nationwide back order per my conversation with 3 gmc/chevy dealerships. At this point my vehicle is unreliable and unsafe to transport myself or my children.

    Source: NHTSA WEB SITE
  • 2020 GMC TERRAIN
    - Rockdale , TX

    Purchased Vehicle brand new- Beck & Masten Buick GM - Houston, TX [XXX] Performed rout maint regularly. Last oil change 1-5-2024 before catastrophic failure and complete engine seizure. Towed to Wiesner GMC [XXX] 1-12-2024: Mileage on car roughly 99K- had no issues no check engine light, no mechanical failure or indication that anything was running other than normal. No Start on [XXX] PM after work, tried to return next day with battery , changed out battery, engine still would not start, after new battery installed and we attempted to start, that is when engine started making loud shaking motion while attempting to start, windshield wipers came on randomly. First initial diagnostic: Found all oils & fluids in check, could not identify cause of failure, would have to break down and take apart. Had to authorize the tear down at a 1800.00 cost, 2/2/2024: Broke down engine, found that the crankshaft would move one way , but not other, removed the engine from transmission and now crankshaft moves freely. Now the AC comp is locked up (excessive play on magnet & clutch) , tech still unable to identify what caused the failure, they advised that they found traces of metal in oil pan, scored cylinder walls, starter shorted as well. They still could not indicate where these metal pieces came from, how or that it was due to owner negligence or manuf defects. Again this is a vehicle with 99K Miles and now we were looking at a 15K price tag for a new engine, turbo, AC, starter on a car that is worth 12K. This is absolutely insane. We reached out for Goodwill Discounts for some assistance since the dealership could not solidify a cause of failure, but GM decided to not warranty and stand behind their product. We were left with a rebuild option for 7500.00. which we had to do in order to get the car back. I am completely disappointed in GM as a company. This engine should have never failed at 99K. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

    Source: NHTSA WEB SITE
  • 2020 GMC TERRAIN
    - Royal Oak, MI

    The contact owns a 2020 GMC Terrain. The contact stated that while driving 50 MPH, the vehicle lost braking power. The driver was able to pull over safely. There were no warning lights illuminated. The vehicle was towed to the local dealer, where it was diagnosed that the vacuum pump had shattered. The vehicle was repaired, but the failure recurred. The contact reached out to a GMC engineer, who informed the contact that the failure was due to the camshaft reluctor. While driving, the vehicle lost engine power. The vehicle was towed to the same local dealer, where it was diagnosed that the throttle body needed to be replaced. The vehicle was repaired, but the failure recurred. The vehicle was towed to the local dealer, where it was diagnosed that the turbo code had a mass air flow sensor failure. The vehicle was repaired. While driving at an undisclosed speed, the check engine warning light illuminated, and the reduced engine power message was displayed. There was blue smoke detected from the exhaust. The vehicle was towed to an independent mechanic, who informed the contact that the throttle had failed. The vehicle was towed to another local dealer, Power GMC Chevrolet of Newport (1422 N Coast Hwy, Newport, OR 97365) where it was diagnosed that the air pipe charge and air cooler needed to be replaced. The vehicle was repaired. The manufacturer was contacted and referred the contact to the local dealer. The failure mileage was approximately 50,000.

    Source: HOTLINE VEHICLE OWNERS QUESTIONNAIRE
  • 2020 GMC TERRAIN
    - Sanford, FL

    This Saturday morning driving my family to Bradenton as I was coming off the hwy to my exit when I experienced a brake fail I thought, brakes got real hard and I couldn't stop the car on time like I wanted to, so I had to press the brakes pedal harder to come to a complete stop, three different places no one knew what could be the problem until I took it to GMC dealership they can only give a code P0556 / U0401 SERVICE BRAKE ASSIST, seems it was too late to checked out they where about to close , something to do with the busters not sure yet but it's getting checked out tomorrow morning, I was driving on cruise control at a speed limit when this happened, will let you know what's the result of my situation.

    Source: NHTSA WEB SITE
  • 2020 GMC TERRAIN
    - Jay, VT

    While driving my vehicle, check engine light came on. Then, my car proceeded to flash about 4 warnings on the dash, Fuel Level Low (had half tank of gas), Engine Power Reduced, Service ESC, and Service Transmission. My vehicle shut itself off while driving 55 down a main highway and put itself into park. Forcing me to pull over and be stranded on the side of the road. In the way of other cars, with no way to get out of the way. I then had to shut car off, wait, and start it back it up. However, after the first time this happened, I cannot drive my vehicle more than 15 to 20 minutes without it doing this to me over and over again. To make matters worse, I am 37 weeks pregnant, and the last thing I need is to be without a car. I also had just gotten my vehicle inspected and an oil change the week before, with no issues to show. The only thing I did to my car before it did this, was remote start my vehicle, which I do every single morning and have for the little over a year I've owned this car. Also, my car has less than 60,000 miles on it!! The mechanic who is currently working on fixing this issue for me, has concluded it to be a throttle body, or the actuator of the car.

    Source: NHTSA WEB SITE
  • 2020 GMC TERRAIN
    - Little Rock, AR

    Brake booster failed with no warning. Brake pad was hard to push down as I exited the freeway. I came close to hitting the vehicle in front of me which would have resulted in a bad car accident. There were no warning. This is extremely dangerous and is a risk to not only the driver but also to vehicles in the path of a vehicle that cannot stop. This needs to be a recall along with the other vehicles that have a recall for this part.

    Source: NHTSA WEB SITE