2021 GMC Terrain problems and complaints

Owners have filed 35 complaints with NHTSA about the 2021 GMC Terrain. The most-reported areas: Engine (9), Service Brakes (8), Power Train (8).

Key takeaways

  • 35 owner complaints on file with NHTSA.
  • 4 involve a crash, 0 a fire, 4 reported injuries.
  • Complaints are unverified owner reports; recalls are confirmed defects.
Complaints by component
ComponentComplaintsShare
Engine926%
Service Brakes823%
Power Train823%
Electrical System720%
Unknown Or Other39%
Forward Collision Avoidance39%
Engine And Engine Cooling26%
Fuel/Propulsion System26%
Lane Departure26%
Suspension26%
Fuel System26%
Gasoline26%

One complaint can name several components, so shares add up to more than 100%.

NHTSA 5-Star crash ratings
VersionOverallFrontSideRollover
2021 GMC Terrain SUV AWD5/55/55/54/5
2021 GMC Terrain SUV FWD5/55/55/54/5

Latest complaints, as filed

Owner-written and unverified by NHTSA.

Engine - filed 2026-09-11

Vehicle Information:Year/Make/Model: 2021 GMC TerrainEngine Type: 1.5L Turbocharged EngineCurrent Mileage: 155,000 miles [1]Description of Safety Defect:I am writing to report a severe, sudden engine and turbocharger failure on my 2021 GMC Terrain that presents an extreme, life-threatening safety hazard. While operat...

Service Brakes - filed 2026-07-12

Vacuum pump failure caused my brakes to lock up and almost caused me to wreck into another vehicle

Service Brakes - filed 2026-07-01

Driving on the Garden state parkway on Sunday night June 28, 2026 I proceed to cross over the ratitan bridge. There was traffic as I was going down the bridge at 70 miles an hour. When I applied the brakes the car would not stop. I had two 6 years old in the backseat. I applied 2 feet to the brake pedal and it was like...

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More for the 2021 GMC Terrain

Complaints are reports filed by owners with the National Highway Traffic Safety Administration. NHTSA publishes them without verifying them, and counts rise with how many cars were sold, so compare years of the same model rather than different models. Crash ratings are NHTSA's own 5-Star Safety Ratings results.