2020 GMC Terrain problems & reliability
186 owner complaints filed with NHTSA for the 2020 GMC Terrain, alongside 2 safety recall campaigns. Last verified Aug 7, 2026. Complaints are unverified reports submitted by owners to the federal Office of Defects Investigation.
Each complaint is counted once (by NHTSA case number), even when it names several vehicles.
3 complaints report injuries (5 injured).
Federal crash records (FARS 2020–2023): 2020 GMC Terrain vehicles were involved in 53 fatal crashes with 18 occupant deaths. Involvement counts are not adjusted for how many are on the road and do not imply fault or a vehicle defect.
Most reported problems
| Component | Complaints | Share |
|---|---|---|
| Service Brakes | 61 | 33% |
| Engine | 55 | 30% |
| Unknown OR Other | 32 | 17% |
| Electrical System | 27 | 15% |
| Power Train | 26 | 14% |
| Fuel/propulsion System | 22 | 12% |
| Vehicle Speed Control | 11 | 6% |
| Forward Collision Avoidance | 8 | 4% |
| Back Over Prevention | 6 | 3% |
| Fuel System, Gasoline | 6 | 3% |
Component groups as classified by NHTSA. A complaint can name more than one component, so shares may sum to more than 100%.
Common symptoms owners describe
Keyword analysis of complaint narratives; one complaint can describe several symptoms.
Mileage when problems occurred
Half of the failures with a reported odometer reading occurred by 48,552 miles (middle 50% between 12,300 and 88,000 miles), based on 37 complaints that included mileage.
Complaints by incident year
What owners report
“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 the curb spot, thanking God I wasn’t dead, I…”
Fuel/propulsion System · filed Aug 5, 2026
“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 check engine light came on and stayed on. It…”
Service Brakes · filed Jul 30, 2026
“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 the lives of their customers.”
Engine · filed Jul 23, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Technical service bulletins
843 manufacturer communications (TSBs, service campaigns, warranty extensions) are on file with NHTSA for the 2020 GMC Terrain. The 10 most recent:
PI to help diagnose A/C concern
PIT5099J · Service Bulletin/Repair Instructions · issued Jul 21, 2026
This preliminary information communicates information about how to determine if a wheel and tires size change is available.
PIT3271Q · Service Bulletin/Repair Instructions · issued Apr 1, 2026
This preliminary information discusses a condition that may arise from the drivers window switch sending an errant message causing the vehicle to enter manual fob learn mode.
PIT5992B · Service Bulletin/Repair Instructions · issued Mar 27, 2026
This Preliminary information communicates the steps on how to save a GDS2 Session Log and upload to a Technical Assistance Case in CX Connect.
PIP6104 · Service Bulletin/Repair Instructions · issued Mar 9, 2026
This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
PIP4902V · Service Bulletin/Repair Instructions · issued Mar 9, 2026
This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC'ss
PIT6425D · Service Bulletin/Repair Instructions · issued Mar 2, 2026
This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC's
PIT6425C · Service Bulletin/Repair Instructions · issued Jan 16, 2026
This PI advised dealer technicians of possible causes of diesel fuel contamination in gasoline powered vehicles and advises of warranty direction.
PIP6098 · Service Bulletin/Repair Instructions · issued Jan 14, 2026
This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
PIP4902U · Service Bulletin/Repair Instructions · issued Jan 8, 2026
This Preliminary Information communication provides information to the technician about vehicles that have had multiple repair attempts that are being performed on customer’s vehicles that exhibit vibration conditions…
PIT5214G · Service Bulletin/Repair Instructions · issued Nov 20, 2025
TSBs are repair guidance manufacturers send to dealers — they are not recalls and repairs are not automatically free. Full documents are available on NHTSA’s site.
Safety recalls
The 2020 GMC Terrain has 2 NHTSA recall campaigns — recall repairs are free at franchised dealers regardless of the vehicle’s age.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →Buying a used 2020 GMC Terrain?
- · Decode the seller’s VIN with our free VIN decoder to confirm the exact year, engine and trim.
- · Check for unrepaired recalls by VIN on NHTSA’s official lookup — recall repairs are free.
- · Owners most often reported problems around 48,552 miles — budget accordingly if the car is approaching that mileage.