6.9

fairly significant
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
8,800 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2020 GMC Terrain drivetrain problems

drivetrain problem

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2020 GMC Terrain Owner Comments

problem #13

Jun 212022

Terrain

  • 50,000 miles

A D V E R T I S E M E N T S

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.

- Royal Oak, MI, USA

problem #12

Dec 202023

Terrain

  • 57,000 miles
The contact owns a 2020 GMC Terrain. The contact stated that while at a stop, there was an abnormal burning odor coming from the vehicle, with the service brake assist message displayed. The brake pedal became firm, and the contact used excessive force to stop the vehicle. The contact pulled into a gas station and restarted the vehicle while the check engine light was illuminated. Despite the failure, the contact was able to drive the vehicle to the residence. The contact inspected underneath the hood and discovered an oil leak as well as black soot that had covered the entire engine. The dealer was notified of the failure and provided the contact with a diagnostic fee for an inspection. Upon investigation, the contact discovered NHTSA Campaign Number: 20V668000 (Power Train) which was linked to the failure. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 57,000.

- O'fallon, MO, USA

problem #11

Jul 012023

Terrain

  • miles
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.

- Sioux Falls , SD, USA

problem #10

Aug 112023

Terrain

  • miles

A D V E R T I S E M E N T S

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

- Sioux Falls , SD, USA

problem #9

Aug 242023

Terrain

  • miles
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.

- Rocky River, OH, USA

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problem #8

Jun 062023

Terrain

  • miles
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~

- Germantown, OH, USA

problem #7

Nov 192022

Terrain

  • miles

A D V E R T I S E M E N T S

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.

- Eagle Rock , VA, USA

problem #6

Sep 272022

Terrain

  • miles
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.

- Sardinia, OH, USA

problem #5

Aug 092022

Terrain

  • miles
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.

- Shelby Township, MI, USA

problem #4

Feb 182022

Terrain

  • miles
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.

- Houma, LA, USA

problem #3

Jun 012020

Terrain

  • 2,400 miles

A D V E R T I S E M E N T S

This vehicle is unsafe due to a violent side to side wobble in the front end much like the Jeep death wobble. This happens constantly anywhere from 30mph - 70mph usually after hitting a small bump or when turning hard. The turning aspect is where it has become very dangerous on slippery surfaces as the car then slides out. I live in the mountains where this is a normal occurance. I am actually afraid to drive this vehicle any longer. The dealers have confirmed the issue, but states that GM does not have a fix for this as of now. I have heard this is affecting only the AWD Terrains and equinox platforms. GM has been unresponsive trying to get an answer or getting this fixed. The car has been into multiple dealerships several times for this same issue and has been happening since the car turned about 2400 miles and has been happening more frequently since then for the past 6000 miles.

- Big Bear Lake, CA, USA

problem #2

Sep 042020

Terrain

  • 5,000 miles
Only a month after purchasing my vehicle I started to feel a wobble in the front end when accelerating up hills and turning while on the gas. I took it to the dealer and they changed out the front tires stating that the problem had been fixed. Once again while driving the problem persisted. I took the car back to the dealer again and they said that they could not find anything wrong and suggested that I make an appointment to go for a drive with the mechanic to show them what is happening. I made an appointment. A day before the appointment I received a call from the dealership stating that an employee recently purchased the same car and they are having similar difficulties. They found online that GMC was requesting information from dealers about the problem and was told that I now need to wait for GMC to come up with a solution. My car shakes every time that I drive it, it's awful, and it only has around 6,000 miles on it. I'm not sure what to do because the dealership told me that I have to wait for a solution. They are not even trying to fix anything at this time. Please help.

- Eynon, PA, USA

problem #1

Aug 302020

Terrain

  • miles
We drove to a farm with a family of 5M kids and an elderly, and parked my car for 2-3 hours in the farm's open area parking lot. Vehicle showed no warning lights, no problems, no issues during our drive to the farm and prior to this trip. Everything was fine when we go there and parked. We were ready to leave the farm to drive back home, but the car simply wouldn't start.the neutral gear didn't work, I attempted many times in 30 minutes to start the car, but it didn't start, continued making the sound of engine attempting to start but not suceeding. 30 minutes later, I decided to give it another try, I was afraid to burn down the starter after attempting so many times. It sounded terrible, screeching metal sound. All of a sudden, the car started. I let it run, afraid to turn it off again. After 15 minutes of running, while we were waiting for roadside assistance to arrive, the vehicle turned off again, all by itself. No one was inside the car, we were waiting outside with the driver door wide open. I called roadside assistance, waited 40 minutes to get a live agent to talk to. The yellow engine light is on. I tried to look in the manual to be able to find anything remotely close to what was happening. Came up with nothing. This was so far the trickiest thing to happen to me. I scheduled an appointment to take the car to the dealership for diagnosis.

- North Hollywood, CA, USA

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