2020 GMC Terrain Complaint Log

I was driving on the interstate when my brakes went out. I was able to get off at and exit and pull into a gas station but had to put on the emergency brake.

Driving down the freeway and all of a sudden got a service break assist notification and without warning I was unable to stop the vehicle. I was able to coast my way off the freeway and upon my exit I tried to pull into an empty parking lot but there was a fire fence I ended up crashing into which is probably what brought the vehicle to a complete stop. This is very dangerous and I have read numerous complaints from other 2020 terrain owners who have experienced the same problem. Mechanic stated I need need vacuum pump for brake booster which of course my warranty doesn’t cover. Something seriously needs to be done about this. My accident could have been a lot worse

After heavy rain the backseat of the car was flooded as well as the rear wheel well likely due to the sunroof not draining properly. This led to electrical failure of the sunroof mechanism and potential to damage other electrical elements. This will be looked at by the dealership but have read that this is a known issue.

2020 GMC Terrain Engine stopped working. Put in new engine. After one week new engine blown. We were 2000 miles away on vacation. I need a free rental I was with no car for a month and after only one week again for 3 weeks. Compensation request: Lost wages Hospital visit Extra hotel nights Gas Food car and insurance payment

While on highway service brake system warning light came on,brake became hard to apply almost causing an accident. Vehicle had to be towed to a repair shop(dealer).after paying over $1600 the problem was not resolved and found there are numerous complaints about issues with the terrain and no recall issued.are they waiting til someone dies before a recall?

My 2020 terrain is now at 33k+ miles, I have had repeated instances with my car not accelerating properly. I would be at a full stop try to start to accelerate and not move push down a little further on accelerator and start crawling forward. I would move approximately quarter mile before the vehicle would jerk and accelerate very quickly to a speed well over where it should go to. I.e. I know because I’m starting in traffic I’m not trying to take off at thirty but when the jerk happens I can be jolted to 40-45 mph. The other issue is people behind you don’t realize what’s going on and I have been hit almost twice thankfully they were able to avoid me by going around. No warning lights have come on. This last insistence not only could I not accelerate, but cruise did not want to turn on, the emergency brake didn’t want to work, and the air conditioner was loosing power. I plan on having an independent service center inspect the vehicle, my husband was able to repeat the issue so I’m sure they will also. The first incident was in May and I have had 5 but thankfully I don’t drive that much.

GMC 2029 Terrain Our car broke down three times after a new engine was put in. After one week it had to be towed again to put in a third new engine. It has been fixed since Aug. 1st but GMC has yet to reunite us with the car 2000 miles away. We’ve made car and insurance payments for almost three months with no vehicle in our possession. It was under warranty. No loaner or rental car has been issued to us. Nobody calls us back. Terrible customer service by GMC.

2020 GMC Terrain SLE Elevation Package 83,000 miles and needs complete engine rebuild @ cost of $10,700 per Dealership Service. Was told “I drove the vehicle with low oil” which Inturn is the cause of needing engine rebuilt. I have had this vehicle serviced, oil changed regularly etc NOT ONE TIME has the oil pressure/low engine oil nor anything related to oil illuminated on my dash. CEL yes after it apparently was too late and damage was done which showed code P06DD And P0324 through OnStar Diagnostics. There are also other complaints with same issue, and no notification of oil /oil pressure issues with relatively low mileage that have led to engine rebuild. I still owe on this vehicle through GM Financial, and a $10,200 engine rebuild on top of that… Not what I would expect out of GMC~

I was driving approximately 75mph on the interstate. 3 hrs into my trip I started feeling hot so I turned the a/c up. In my peripheral vision I saw orange and thought a car was beside me on fire. Immediately I realized it was my vehicle. I immediately slowed and came to a stop. I put it in park and opened the door. By the time I started to exit there were flames higher than the rear windows. A car that was behind me stopped. They said about a mile back there was a spark under the car by the rear tire. Then it went up in flames.

The airbag system on my 2020 GMC Terrain has an intermittent malfunction. The airbag warning light turns on and off and the diagnostic code B0014 has been identified by a dealership. When the warning light is on, the airbag system may not deploy properly in a crash, creating a safety risk. The vehicle has approximately 49,000 miles. The problem has occurred for about three years. The dealership repaired the issue when the vehicle was first purchased and the light went off temporarily, but it returned a few months later. A second dealership attempted a repair and again the light went off temporarily before returning. The issue continues to occur intermittently. The warning lamp for the airbag system appears on the dashboard. The vehicle has been inspected by dealerships but the problem has not been permanently fixed.

Screen system prompts to accept terms of service while moving. This is unsafe and the system should know it is in motion. Unsafe programming, require manufacture to only prompt when system is at reset. Require OTA reprogramming.

My vehicle begin stalling when accelerating (mostly after stopping) June 2023. My vehicle has almost cause me to have two accidents because it intermittently stalls when I try to cross an intersection. This is my fourth time taking my vehicle to the GMC dealership, and they tell me they can't find anything wrong if there is not a code. I have reached out to Corp, and I'm waiting to see if they can help get to the bottom of my problem. My car has been sitting at the dealership since June 30th 2023....I call the dealership periodically, and they never reach out to let me know what's going on. I am afraid to drive my vehicle at this time because next time another car may not be able stop and give me time to get across the road. I'm filing this complaint because I seriously think someone is gonna get killed.. Thank you

The contact owns a 2020 GMC Terrain. The contact stated that while attempting to restart the vehicle, the vehicle failed to start. The vehicle was towed to the local dealer who diagnosed that the fuel pump was faulty and needed to be replaced. The vehicle was not yet repaired. The manufacturer was not yet notified of the failure. The failure mileage was 42,000.

I was driving down The expressway. The traffic in front of me came to a stop. When I went to apply the brakes I had no breaks. The pedal was as hard as A rock So when I realized I couldn't stop I swerved over into the breakdown lane. And continue to pass cars at a high rate of speed until I got the car to stop. There were no check engine lights on Then I had the car towed to the Dealership Where they tell me is a break vacuum pump. That has damaged The Cam shaft. Pistons and rods in the engine. Totaling $7200. In damage. No one seems to care and I still owe 20000 on the car. Car has 71000 miles on it.

On 4/10/2023, I took my vehicle to a local GMC dealership because it was stalling and didn't have any power. Upon accelerating the vehicle it would stall and take off at a high speed. The dealership has had my vehicle periodically from April 2023 and it presently sets at the dealership because they ain't getting a code, But after the dealership drove the truck for over 200 miles, they were finally able to duplicate the stalling yet are not able to diagnose the problem!! This vehicle is very dangerous to be on the road and I have almost gotten hit twice and I'm not driving the vehicle anymore at this time. I have previously reached out to you all and I would be most thankful if you could get in touch with me. Thank you

The contact owns a 2020 GMC Terrain. The contact stated that after refueling the vehicle, the vehicle failed to restart. The message "Battery Low - Start Vehicle" was displayed. The vehicle was towed to the dealer, where it was diagnosed that the fuel sensor module and fuel pump needed to be replaced. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 23V013000 (Fuel System, Gasoline); however, the VIN was not included in the recall. The manufacturer was not made aware of the failure. The failure mileage was approximately 42,510.

This GMC I just purchased in October 22 2022 and have been complaining since December 9,2022 the vehicle emergency braking will activate when I'm driving down the interstate or local roads I could be doing 70 and brakes will just lock up throwing me and my son forward , this has happened 4x , Gas Pedal when taking off at red light or pulling out the vehicle is hesitant and will not go this has happened on 3 different occasions. I called roadside on star they said there is a problem with the on star saftey feature will not work properly this was towed 2x to different shops, Also while driving this vehicle it will just ingage itself in park while driving called on star they did diagnostic there was all kinds of Coded for Transmission and Engine as well as Emissions this vehicle is a safety hazard.. And I have tried to take back to dealership where I purchased they keep making excuses to not see this CPO with lifetime Warranty and still under warranty from GMC vechle Mileage was at 29k when problems stared vehicle only has 31k I can't drive this vehicle due to my son's and myself along with others saftey this is ridiculous and also GMC just informed me the Vin # they have for my vehicle and whats on it are two different numbers! Yet nothing is being done I'm paying for a vehicle that I can't drive I have proof GMC knows about the fraud from dealership but GMC says its a sales thing This vehicle has been flooded two mechanics have confirmed and GMC is aware so why not do something I don't know exactly the history and GMC doesn't either please someone contact me GMC this is crazy and you know it's a safety issue with this 2020 GMC Terrain you even said so

Radio goes from normal volume to as loud as possible while just driving.scares ya to death! Can't turn volume down with out 1st shutting off radio and turning it back on.dealship stayed there isn't a problem they could find.Blu tooth cuts in and out and locks the radio up untill you shut vehicle off and restart.shows you still on a call even though you have disconnected phone from radio.volume issue has happened several times

The contact's friend's son owns a 2020 GMC Terrain. The contact stated that while her friend was driving at an undisclosed speed, the brake pedal went to the floorboard while depressed. The brakes failed to immediately stop the vehicle. Additionally, the vehicle made grinding sounds while driving. The vehicle was taken to the dealer, where the vacuum pump, exhaust camshaft, and valve cover gasket were replaced; however, the vehicle lost motive power while driving. The vehicle was towed back to the dealer, where it was determined that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and informed the contact that there was no recall associated with the VIN. The failure mileage was approximately 48,552. The contact stated that additionally, the check engine light came on without cause. The contact is unsure why that is because a diagnostic test had just been performed.

2020 GMC TERRAIN. CONSUMER STATED THAT THEIR VEHICLE STARTED PULLING AND DRAGGING WHILE DRIVING.

The brake system is only working at about 5%. There are known defects with other GMC models of this year and this vehicle should be reviewed .

Driver seat belt exhibits signs of fraying in area of belt hidden from view when not in use. When extended, hair-like fibers extend out, primarily from the car-forward side of the belt in the area coming out of the B-pillar and from behind the trim. It is available for inspection. Concerned that this may continue to degrade the integrity of the seat belt over time. There could be something sharp in the retractor, or flash on a piece of plastic trim hidden from view causing this. My understanding is that if there is a small nick on the edge of a safety belt it can tear across, and concerned that this condition could lead to a similar outcome over time and if the vehicle were involved in an accident. Upon taking to local dealership, was advised that this is a normal condition and not a concern. Advisor said technician told him that it is not fraying, it is a normal condition that can be exhibited by the belt fibers, especially towards the edges. They said the central portion of the belt is not exhibiting a similar condition and therefore not a concern. The fibers seem to have grown in quantity since vehicle purchase. I first recall seeing them during the pandemic, although became more concerned over time and finally took in prior to warranty expiration for review.

None of these features have ever worked

I just purchased this vehicle about 2 weeks ago, and was driving through the fog/cold weather and my check engine light came on. Went to O'Reillys and had them check the code. Came up as P0299 (My car was telling me that the engine power was decreased) I had a loss of power I could feel while driving as well. The code said turbo under boost. After I got back into town and the weather was warmer and no fog was present, the turbo started working again. I brought my vehicle into the dealer where I bought it from and they took it to their mechanic and supposedly performed an "update". I will see if I continue to have the same issue in cold weather as I live in Idaho and go to the mountains often.

My service brake assist light came on and then within seconds my vehicle then said engine power has been lowered and my vehicle pretty much shut down no steering no brakes couldn't do anything. Took it into the repair shop and my vacuum pump has shattered and now damaged my camshaft. I am aware there's been many other vehicles recalled with GM's vacuum pumps and I'm not sure why my year and model has not been included when it's doing the same thing and not to mention I have seen countless other cases of people saying same things happen to them with their GMC terrains.

The car has been in the shop for the turbo being over boosted four times and is getting hot, so they put thermo tape on the part, and now what if the car catches on fire? This is an electrical issue that needs to be solved.

Turbo failed. Car ran fine with no warning lights. Stopped at red light entering interstate and then could not accelerate which left us stuck in traffic. When it did move it would not shift and took over a mile to get above 20mph in a 65mph zone.

1- at 71,000 miles in 2022 brake vacuum pump “exploded” broke into many small pieces in the middle of driving. Causing brakes to lock. Brake pedal was brick hard. Hard to maneuver the car out of traffic without causing a collision. Luckily car was not being driven at high speed. At time of repair costing $1,000 Mechanic informed me that the pump was made out of a non metal material and he could not fish the small particles out of the motor with a magnet. The motor would need to be taken apart, cleaned out and reassembled….. From this point forward the car drives in “low engine power mode” even with repairs completed and codes cleared. 2- 2 years later the same part “brake vacuum pump” exploded again. Another $1000 repair. At this time we discovered that the fine particles that were not removed from motor has now knocked the timing off by 8%. Also it has caused a knick in a seal causing an oil leak under 100k miles $1800 repair. After these extensive repairs…… The car emits gas fumes into cabin. The smell is so strong it can’t be parked in the garage because it circulates through the house. Even when car is not running. The Car can’t be driven because risk of fire or explosion from gas. Fuel system gets cleaned. Injectors replaced. The car temporarily runs without the gas smell. 2 weeks later the gas smell returns Come to find out the fuel pump failed. Search online and find there is a recall for fuel pumps in this same make model and year. But not this vin number. The car has been a headache from day 1. Recall the whole car at this point, to have so many faulty parts in such major systems of a car is crazy.

In January 2022, I purchased a 2020 GMC Terrain from a local GMC certified dealership along with an extended warranty. In July 2022, I started to experience intermittent acceleration issues. The issue only presented itself upon vehicle startup and was very sporadic. Upon startup, the vehicle was very slow to accelerate even with the gas pedal depressed to the floor. The vehicle would move at an extremely slow rate of speed for approximately 10 to 15 seconds before the vehicle would engage and actually start moving forward at the expected rate of speed. This would happen 4 to 5 consecutive times before things seemed to "warm up" and run smoothly. It proved to be dangerous at intersections if making a left hand turn into oncoming traffic or during heavy traffic times. From the beginning of July to Aug 9th, this has happened on 5 separate occasions. The story is the same, I start the car after it has been sitting for a bit (it's been from several hours to several days) and the issue will present itself without warning. There are no fault or error codes. I've taken the vehicle to my mechanic as well as the dealership where I purchased the car and both have run diagnostics on the vehicle with no luck. My mechanic did drive the car and he experienced the issue first hand but he could not figure out what was wrong. In the event other Terrain owners are experiencing this same sporadic acceleration issue with no fault or diagnostic codes, I wanted to make sure we documented our issue. I did not record the dates of the first few instances but the last two have been July 24th and August 9th.

The emergency breaking system failed to engage. Failure to engage caused collision with another car

I noticed a sticker in driver door stating recall however no evidence. The vehicle will not pull hills, back up on a hill and will not accelerate over 25 miles per minute. Dangerous to drive on roads. Took vehicle to a GMC dealer for diagnostic test, received the report for what the report found. Took the report to auto shop to get repaired however the vehicle still continues with same issue. Took the vehicle to another auto shop. I was informed of some differences added issues. I had those issues fixed. The vehicle still running the exact way after all of the repairs. The top hood on the vehicle paint starts peeling after a year of owning it. I purchased the vehicle at Kia of Gardendale 2020. No one had any answer regarding the situation. Very disappointed with a GMC vehicle. I just want to know the mystery.

Service brake assists light flashes on dashboard . Steering wheel locks up and jerk’s loose suddenly when making a right turn, in these moments when the steering wheel jerks loose ;hands are off taken off the steering wheel otherwise injury can occur. Battery life 2 -yrs old is not performing optimally. Can not hold a sufficient charge and ESC light flashes. Vdnt valve leaks discovered.

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.

VEHICLE HAS 56801 MILES AND AIR CONDITIONING COMPLETELY WENT OUT. i HAVE ALSO REPLACED WINDSHIELD WIPERS TWICE IN 6 MONTHS. THIS IS MORE THAN ANY OTHER VEHICLE i HAVE EVER OWNED (i HAVE HAD THE VEHICLE 1 YEAR NOW)

I had been fishing at the lake and went to leave and when I got in my car I put it in reverse and backed up then put in drive to pull forward, only I pushed the throttle all the way to the floor and the vehicle was completely unresponsive. I put it back in reverse and backed up a little more then put back in drive and same thing happened. I then put it in neutral and have it gas and with the pedal to the floor it barely revved the engine at all. I put it back in drive and floored it again and started turning the when from side to side still nothing. I put it in park then back in drive and with the gas pedal to the floor it barely started to creep forward. It continued to creep for about 40ft then all of a sudden the throttle worked and vehicle jerked forward. 2 days later I was driving in town with my daughter in the car and slowed down before turning up a steep hill and the vehicle did the same thing. Gas pedal to the floor and wouldn't accelerate. Only this time I almost got rear ended. I have contacted the dealer and told them I need a loaner while my vehicle is fixed and their response was "I don't know what to tell you we don't have any". I called GM and they said they would contact the dealer and see if they just don't have any loaners available or of they don't offer them and said they would call me back. The end of the next day I still haven't heard from them so I reach out to them again this time being told "an owning advisor has already handled your claim, sorry you haven't been updated yet". I don't need updates, I need a safe vehicle for me and my kids! My car has only 57XXX miles plus I bought a 100,000 extended warranty. Please hold GM accountable for their poor quality of vehicles and even worse customer service!

Dash had gone black intermittently, did not know what speed I was going. OnStar called oor phone multiple to notify us that our airbags we're offline for ten days no warning light on dash until one to two days later . Took to service was informed that gear shift control, engine control module, passenger presence module and airbag sensor needed replaced. All within a month of purchase of said USED vehicle. Vixed under warranty. Then another monther later, got warning on dash saying "conditions not current for shifting", park break light came on, and a p in a yellow circle with a wrench under it came on. Serive did fix vehicle, but could not verify message on dash about conditions not favorable... Also recalibrated breaker. Complained numerous times to dealer about these issues and was told "live with it".

UNKNOWN...ACTS AS IF ITS A SMART CAR THAT'S NOT REALLY A SMART CAR

The engine cutoff while driving through a major intersection in 3/2022 with no warning lamps, messages or other symptoms of the problem prior to the failure. Dealership replaced the fuel pump module. Subsequently, the engine cutoff while driving in 5/2023. Dealership replaced the fuel pump module. Each of these occurrences placed my life, my passengers life and the lives of others on the road in danger as an accident could have resulted if I was not able to coast out of harms way. GMC has an existing recall on the fuel pump module for 2021 - 2022 Chevrolet Equinox and 2022 GMC Terrain vehicles. Why did this happen a second time after replacing the fuel pump module? Are they using a module included in the recall? I was charged $ 591 dollars for the repair in 3/2022 and no charge in 5/2023 as they stated it must have been a faulty module. I have no confidence in my safety and the module they used in 5/2023 is not faulty.

Brakes hard to press. Almost cause an accident on interstate. Was able to contain vehicle. Took to autozone to assessed and it said Powertrain System. Brake Booster Senor Circuit.

Interior lights stays on at night while driving and when parked. Tried turning it off but it won’t turn off

The engine will never go into 9th gear! What's the point of GMC doing a 9 gear transmission to help with fuel, if it never actually goes into the 9th gear?

As I was driving on the highway in New York on Route 17 south near exit 111, I tried to accelerate but when I did the car went slower and the check engine light and traction control lights came on. I was right in front of a huge truck and thank God I was in the right lane that I was able to quickly get on the shoulder and turn the car off. I was able to make it to where I was going, but it was very nerve wracking. I took the car to the dealer service center and was told that it was probably a fuse issue. It turns out my entire engine has to be rebuilt. I have approximately 25,000 on my car, how could it require an entire engine rebuild? The dealer has gotten me two rentals cars that only last 5 days at a time each time and now I’m driving a dealer loaner. It’s been 3 weeks and still nothing. I’m still making payments on my car.

Infotainment system shuts off completely. Disables blinker. Bluetooth and USB ports continuously went in and out and wouldn’t stay connected. Took to dealership on 02/07/2022 and was advised the system needed an update and the USB port needed to be replaced. USB port was replaced and software bulletin #20-NA-171 was applied. I picked up my vehicle on 02/08/2022 and the infotainment issue has not been corrected. It turned off again. USB ports seem to be working as they should for now. Also an issue with rear camera. Camera view sometimes shows a fisheye lens instead of normal camera view. Rear camera will sometimes stay on once car is in drive for a few seconds. I also notice a noise and vibration within my gas pedal randomly while driving. Clearly there are multiple issues that GM needs to acknowledge. It’s not a coincidence that this is happening to multiple people.

This 2020 GMC Terrain has a "feature" called autostop. This is not a switch to turn this off. It would not be so bad if the engine would run for 5 minutes at a stoplight before stopping the engine but it immediately shuts down the engine after a stop. This is getting annoying and dangerous due to the delay in getting the car moving. I have only had the car for a month. I understand that later gmc cars have a disable switch. This car should be recalled and either disable the auto stop permanently or be able to disable the "feature" on demand. Problem: potential crash hazard due to car not starting and damage to battery and starter.

The engine "Auto Stop" feature can have enough of a delay to allow the accelerator to be pressed as the engine starts causing it to lurch forward rather than accelerate smoothly. It also can cause a delay when pulling out into heavy traffic. There is currently no way to temporarily or permanently defeat the system on this GM model according to GM service department. Though I am sure it is operating as designed for certain owner driving styles and traffic conditions this can be a serious hazard. Car makers should be required to either disable the feature permanently by owner request or have a method for the owner to bypass the system. With less than 250 miles I have experienced 2 incidents of almost hitting the car in front of me from a stop and 1 of almost being hit pulling into heavy traffic from a stop. I see many other similar complaints and hope this can be addressed before someone is hurt or worse due to it.

While driving instrumental panel and infotainment panel completely blacked out for no reason at all. This is the second time in two days this has happened.

Instrument panel and infotainment system panel completely blacked out while driving vehicle

The contact owns a 2020 GMC Terrain. The contact stated while driving at various speeds, the vehicle lost brake functionality while depressing the brake pedal. The contact stated no warning light was illuminated. The vehicle was towed to a local dealer where it was diagnosed with needing the vacuum pump replaced. The vehicle was repaired however, the failure persisted. The manufacturer was not informed of the failure. The failure mileage was approximately 40,000. The VIN was unavailable.

I had an incident this morning when I put my car in park position it remained in reverse. I took it out of park and put in drive then I put forward but the vehicle still remained in reverse. I turned the vehicle off and it still remained in reverse. Ali controls on infotainment panel was inoperable. ( example: I couldn’t turned off or turned radio).

loss of oil due to engine defect and need new engine. engine and car at dealership. engine has not been torn apart to find cause. occupants could have died because of engine stoppage... GM wants owner to pay over 15,000 for new engine and instillation. car under new car warranty has 24211 miles. no early warning lights of low oil.... Owner took car in immediately when warning lights appeared 9-27-21 and GMC dealership improperly serviced . on 10-14-21 same warning lights reappeared and taken immediately to same close dealership. Now told new engine needed.