Most common 2021 GMC Terrain problems
Share of the 36 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
GMC Terrain complaints by model year
Best Terrain years: 2021, 2016, 2017. Years to avoid: 2024. Compare all years →
2021 GMC Terrain recalls (2)
Child seat › Vehicle latch anchor
General Motors, LLC (GM) is recalling certain 2020-2023 Chevrolet Equinox and GMC Terrain vehicles. The four rear-seat lower child seat LATCH anchorage bars may have excessive powder coating, which could prevent a child seat from being installed with the anchorage bars.
Remedy: Owners are advised to install child seats using the vehicle's rear seat belts until the remedy is complete. Dealers will inspect the latch anchorage bars, and remove and replace the finish, as necessary, free of charge.
Tires › Tread/belt
General Motors, LLC (GM) is recalling certain 2021-2022 Chevrolet Equinox and GMC Terrain vehicles equipped with certain Hankook tires. The tires may have been manufactured with an insufficient amount of curative agent, which could cause tread separation.
Remedy: Dealers will inspect the tire DOT numbers, and replace any affected tires, free of charge. Owner notification letters were mailed on August 31, 2021.
What 2021 GMC Terrain owners say
Engine & cooling
The contact owns a 2021 GMC Terrain. The contact stated that the transmission was previously replaced. The contact stated that upon starting the vehicle, the check engine warning light illuminated. The failure had occurred intermittently. Additionally, the contact stated that while driving approximately 15-20 MPH and depressing the accelerator pedal, the vehicle failed to respond for approximately 1 minute. The vehicle was taken to the Nissan dealer it was purchased several times. The dealer retrieved diagnostic trouble codes: P057C and P057E, and the brake pedal position sensor was replaced twice; however, the failure persisted. The Nissan dealer took the vehicle to a GM dealer, where the cause of the failure could not be determined. The vehicle was not repaired. The contact related the failure to TSB Number: PIT5994 (Diagnostic Tip for Reduced or Low Engine Power on Acceleration). …
The contact owns a 2021 GMC Terrain. The contact stated while driving 5 MPH, the vehicle stalled. There was no warning light illuminated. The contact stated that the failure was like GM Product Safety Recall: N222372310 (Inadequate Fuel Pump Flow). The vehicle was towed to an independent mechanic, who determined that the fuel pump had malfunctioned and damaged the camshaft. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The approximate failure mileage was 86,000.
Transmission & drivetrain
The contact owns a 2021 GMC Terrain. The contact stated that the transmission was previously replaced. The contact stated that upon starting the vehicle, the check engine warning light illuminated. The failure had occurred intermittently. Additionally, the contact stated that while driving approximately 15-20 MPH and depressing the accelerator pedal, the vehicle failed to respond for approximately 1 minute. The vehicle was taken to the Nissan dealer it was purchased several times. The dealer retrieved diagnostic trouble codes: P057C and P057E, and the brake pedal position sensor was replaced twice; however, the failure persisted. The Nissan dealer took the vehicle to a GM dealer, where the cause of the failure could not be determined. The vehicle was not repaired. The contact related the failure to TSB Number: PIT5994 (Diagnostic Tip for Reduced or Low Engine Power on Acceleration). …
The contact owns a 2021 GMC Terrain. The contact stated while driving at various speeds, the transmission erroneously shifted to the neutral, causing the vehicle to decelerate. After restarting the vehicle, the vehicle operated normally. During the failure, the message " Power Reduced" was displayed. The cause of the failure was not yet determined. The local dealer was notified of the failure. The vehicle was not repaired. The manufacturer was not contacted. The failure mileage was 36,000.
Brakes
The contact owns a 2021 GMC Terrain. The contact stated that the transmission was previously replaced. The contact stated that upon starting the vehicle, the check engine warning light illuminated. The failure had occurred intermittently. Additionally, the contact stated that while driving approximately 15-20 MPH and depressing the accelerator pedal, the vehicle failed to respond for approximately 1 minute. The vehicle was taken to the Nissan dealer it was purchased several times. The dealer retrieved diagnostic trouble codes: P057C and P057E, and the brake pedal position sensor was replaced twice; however, the failure persisted. The Nissan dealer took the vehicle to a GM dealer, where the cause of the failure could not be determined. The vehicle was not repaired. The contact related the failure to TSB Number: PIT5994 (Diagnostic Tip for Reduced or Low Engine Power on Acceleration). …
The contact owned a 2021 GMC Terrain. The contact stated while the brake pedal was depressed, it was released and the vehicle suddenly accelerated aggressively. The contact attempted to avoid crashing into the vehicle in front and swerved however the front of the vehicle still impacted the vehicle in front. The air bags deployed upon impact. A police report was filed. The contact stated no medical attention was provided, but did suffer bruises from the air bag and seat belt. The vehicle was towed to an independent mechanic. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was not available.
2021 GMC Terrain engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 1.5L 4-cyl turbo | 9-speed automatic | FWD | 25 / 30 / 27 |
| 1.5L 4-cyl turbo | 9-speed automatic | AWD | 25 / 28 / 26 |
EPA ratings. Class: Small SUV.
Frequently asked questions
Is the 2021 GMC Terrain a good car?
Based on 36 owner complaints filed with NHTSA, the 2021 Terrain rates better than average: 69% fewer complaints than a typical year of the Terrain at the same age. It is one of the best Terrain years by this measure. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 2021 GMC Terrain?
The engine & cooling — 11 complaints, 31% of all complaints for this model year, most often about engine › engine control module (ecu/ecm). Next are the transmission & drivetrain (8) and brakes (8).
How many recalls does the 2021 GMC Terrain have?
There are 2 recalls for the 2021 GMC Terrain, the most recent from May 11, 2023 (vehicle latch anchor). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the GMC Terrain?
The best years by complaints, compared at the same age, are 2021, 2016 and 2017. Years to avoid or approach with caution: 2024. See the full GMC Terrain years comparison.
At what mileage do 2021 GMC Terrain problems happen?
The median mileage reported in complaints is about 79,000 miles; 50% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.