2020 GMC Terrain Common Problems & Defect Telemetry
Authoritative defect intelligence synthesized from 190 verified NHTSA owner complaints, 2 federal safety recalls, and interquartile failure mileage telemetry.
The 2020 GMC Terrain receives a 6.2/10 MazicBay Reliability Index based on 190 verified NHTSA federal complaints and 2 safety recalls. The primary reported failure mode is Engine Stalling, Oil Consumption & Cooling Defect Reports with a median failure point at 71,500 miles (IQR: 54,750 – 122,148 mi). Out-of-warranty repairs benchmark at $950 – $3,200 .
22.4 complaints / 10k sold
Verified US federal records
Crash, fire & stall audit
2 Active / Free Remedies
Top Reported Problem Clusters (7)
Engine Stalling, Oil Consumption & Cooling Defect Reports
- Engine sudden stall / hesitation while driving
- Abnormal oil burning / consumption
- Check Engine Light (MIL) flashing
- Engine overheating / coolant loss
“While driving, I suddenly smelled something burning. Immediately after, a warning popped up stating 'Engine power is reducing,' the check engine light came on, and I experienced a sudden, near-total loss of power braking assist, making the brake pedal extremely hard to press. ...”
“While driving north in interstate 79, the brakes became very hard to push making it difficult to stop the vehicle. We got off the interstate and proceeded back home. The brakes were as hard as a rock to push and it was difficult to stop the vehicle. When this happened, the che...”
“Vacuum pump failure causing sudden and unexpected hard brake pedal and loss of braking coming off the highway. Ended up catastrophic engine failure. This is the SECOND incident with this vehicle of the exact same problem. GMC refuses to address this issue and continues to risk...”
Service Brakes, ABS Actuator & Master Cylinder Reports
- Spongy or hard brake pedal travel
- ABS / Brake warning light illuminated
- Extended stopping distance / pedal vibration
“While driving, I suddenly smelled something burning. Immediately after, a warning popped up stating 'Engine power is reducing,' the check engine light came on, and I experienced a sudden, near-total loss of power braking assist, making the brake pedal extremely hard to press. ...”
“While driving north in interstate 79, the brakes became very hard to push making it difficult to stop the vehicle. We got off the interstate and proceeded back home. The brakes were as hard as a rock to push and it was difficult to stop the vehicle. When this happened, the che...”
“Vacuum pump failure causing sudden and unexpected hard brake pedal and loss of braking coming off the highway. Ended up catastrophic engine failure. This is the SECOND incident with this vehicle of the exact same problem. GMC refuses to address this issue and continues to risk...”
Electrical Parasitic Drain, Infotainment & Harness Reports
- Unexplained battery drain after sitting overnight
- Infotainment display / instrument cluster blackouts
- Accessory malfunction / alternator fault warnings
“While driving home from work my 2020 GMC Terrain stalled and turned off. I was on a very busy 2 lane road, crossing a intersection in a tourist area in .... This could have be come fatal very easily. I was able to get the car started and Home but had to take it very slow. Next...”
“The back passenger seat exploded and caught fire, burning the back of the seat in front and burning the ceilings. Inside the whole vehicle is black from smoke damage. Incident assessed by fire marshal who has ruled as electrical issue. No warning lights or systems displayed an...”
“Backup camera stopped working and displays a blue screen stating “service backup camera.” This was an issue when the vehicle was under 3 year manufacturer bumper to bumper warranty and was fixed by dealer at no cost. Now this same issue has occurred again approximately 3-4 yea...”
Transmission Hesitation, Hard Shifting & Slipping Reports
- Hard gear shifts / delayed engagement into Drive/Reverse
- Transmission shudder / jerking under acceleration
- Transmission slipping between gears
“While driving, I suddenly smelled something burning. Immediately after, a warning popped up stating 'Engine power is reducing,' the check engine light came on, and I experienced a sudden, near-total loss of power braking assist, making the brake pedal extremely hard to press. ...”
“Because of the intentional failure of GMC and there promise of “We are Professional Grade”, I almost got plowed down by a semi when the car began to quit on the highway going 60. After pulling into the next driveway, which happened to be a Parker’s Kitchen, and ending up on th...”
“The contact owns a 2020 GMC Terrain. The contact stated that shortly after refueling the vehicle, the vehicle suddenly stalled while accelerating from a stop light. The contact stated that after the vehicle stalled, the transmission failed to shift out of park, and the vehicle...”
Fuel Pump Pressure Loss & Fuel Delivery Defect Reports
- Sudden loss of propulsion power at highway speeds
- Extended engine cranking / failure to restart
- Fuel odor near fuel tank / engine bay
“While driving home from work my 2020 GMC Terrain stalled and turned off. I was on a very busy 2 lane road, crossing a intersection in a tourist area in .... This could have be come fatal very easily. I was able to get the car started and Home but had to take it very slow. Next...”
“Vehicle was filled with a full tank of gas, went to crank the car up to go home from work it acted like it wanted to crank but seemed to be getting no gas. Diagnostic was performed and the fuel pump control module failed. I thank God It did not start because if it did and I ju...”
“The contact owns a 2020 GMC Terrain. The contact stated that shortly after refueling the vehicle, the vehicle suddenly stalled while accelerating from a stop light. The contact stated that after the vehicle stalled, the transmission failed to shift out of park, and the vehicle...”
Electric Power Steering Assist & Suspension Noise Reports
- Sudden loss of electric power steering assist
- Steering wheel pull or highway wander
- Clunking / knocking noise over bumps
“I was driving 55 miles an hour on an Expressway. And suddenly my truck just shut off.The brake became very hard unable to break very scary situation for me and my children. Engine power was reduced and would not start, many errors came up. The vacuum pump failed, which also ca...”
“I own a 2020 GMC Terrain with approximately 110,000 miles. While driving in winter, the vehicle suddenly lost cabin heat and defrosting capability. The temperature gauge began fluctuating and the cooling fans continued running after the vehicle was shut off. A mechanic diagnos...”
“The bolts fell out and the bracket that holds the drive shaft in place fractured while driving.”
Airbag Occupant Detection & Inflator Defect Reports
- SRS Airbag warning lamp illuminated
- Passenger occupant classification sensor failure
- Seat belt retractor lockup
“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...”
“... once again while diving down the road 45mph Terrain once again goes in to park ,I was lucky the lady behind me wasn't to close .Also I contacted onstar when I was able to get vehicle moving at the store ..I told her what happen she ran diagnostics while parked at store sai...”
“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 inspect...”
Official NHTSA Safety Recalls (2)
POWER TRAIN:AUTOMATIC TRANSMISSION
Summary: General Motors LLC (GM) is recalling certain 2018-2019 Chevrolet Cruze and Buick LaCrosse, 2018-2020 Chevrolet Equinox, Chevrolet Traverse and GMC Terrain, 2018 Chevrolet Malibu, 2019-2020 Buick Encore, Buick Enclave, Cadillac XT4, Chevrolet Blazer and GMC Acadia, and 2020 Cadillac XT6 vehicles. The start/stop accumulator endcap may have missing bolts.
CHILD SEAT:VEHICLE LATCH ANCHOR
Summary: 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. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 225, "Child Restraint Anchorage Systems."
Pre-Purchase Inspection Checklist for 2020 GMC Terrain
Before purchasing a used 2020 GMC Terrain, perform the following targeted inspections based on reported federal defect patterns:
Scan the OBD-II port under the dash for pending freeze-frame codes (e.g. P0300 misfires, P0087 fuel rail pressure, P0420 catalytic efficiency).
Test vehicle at low-speed stop-and-go and highway merges. Check for delayed reverse engagement or gear shift shudder between 2nd and 3rd gears.
Verify that all 2 NHTSA safety recall campaigns have been performed by an authorized dealership using the VIN.
Ensure the instrument cluster, center screen, and auxiliary charging ports operate with stable 12.0V–14.4V alternator voltage.
Defect & Reliability Q&A: 2020 GMC Terrain
Is the 2020 GMC Terrain a reliable used car?
The 2020 GMC Terrain earns a 6.2/10 MazicBay Reliability Index based on 190 federal owner reports. Vehicles maintained under factory service schedules exhibit strong longevity past 150,000 miles.
What is the most frequent defect reported on the 2020 GMC Terrain?
The leading complaint category is Engine Stalling, Oil Consumption & Cooling Defect Reports, with a median failure point around 71,500 miles (IQR: 54,750 – 122,148 mi).
Are there free recall repairs available for the 2020 GMC Terrain?
Yes, the NHTSA records 2 safety recall campaign(s) for this model year. All safety recalls are performed 100% free of charge by authorized franchise dealerships regardless of vehicle warranty status.