2018 GMC Terrain problems and complaints
Owners have filed 220 complaints with NHTSA about the 2018 GMC Terrain. The most-reported areas: Service Brakes (82), Engine (53), Power Train (41).
Key takeaways
- 220 owner complaints on file with NHTSA.
- 14 involve a crash, 1 a fire, 12 reported injuries.
- Complaints are unverified owner reports; recalls are confirmed defects.
| Component | Complaints | Share |
|---|---|---|
| Service Brakes | 82 | 37% |
| Engine | 53 | 24% |
| Power Train | 41 | 19% |
| Electrical System | 35 | 16% |
| Unknown Or Other | 34 | 15% |
| Air Bags | 14 | 6% |
| Hydraulic | 13 | 6% |
| Fuel/Propulsion System | 12 | 5% |
| Forward Collision Avoidance | 8 | 4% |
| Vehicle Speed Control | 8 | 4% |
| Electronic Stability Control (esc) | 7 | 3% |
| Steering | 6 | 3% |
One complaint can name several components, so shares add up to more than 100%.
| Version | Overall | Front | Side | Rollover |
|---|---|---|---|---|
| 2018 GMC Terrain SUV FWD Later Release | 5/5 | 5/5 | 5/5 | 4/5 |
| 2018 GMC Terrain SUV AWD Later Release | 5/5 | 5/5 | 5/5 | 4/5 |
| 2018 GMC Terrain SUV AWD Early Release | 4/5 | 5/5 | 4/5 | 4/5 |
| 2018 GMC Terrain SUV FWD Early Release | 4/5 | 5/5 | 4/5 | 4/5 |
Latest complaints, as filed
Owner-written and unverified by NHTSA.
Service Brakes, Hydraulic - filed 2026-09-14
The contact owns a 2018 GMC Terrain. The contact stated that while driving 20 MPH, the brake pedal was firm and the "Service Brake Assist" message was displayed on the instrument panel. The contact used excessive force to depress the brake pedal while stopping the vehicle. The vehicle was driven to the destination and ...
Carry Handle, Shell, Base,tether, Lower Anchor (on Car Seat Or Vehicle) - filed 2026-08-28
I purchased an Evenflo Shyft Intuiti Travel System with a Revolve180 LiteMax NXT infant car seat. The car seat was manufactured on 03/27/2025, model TS100212542. I was notified by Amazon that the car seat was recalled due to a calibration issue with the level indicator that caused the product not to meet applicable fed...
Unknown Or Other,service Brakes,engine - filed 2026-08-24
Approximately 3 miles from my residence my car display flashed "Reduced Engine Power" and slowed down. When I reached a stop sign and tried to stop, my brakes were stiff and I was unable to stop. I went through the stop sign. I continued to my residence at 10mph and backed into a parking space with a curb to help stop ...
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More for the 2018 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.