AI Damage2018 GMC Terrain: common problems
Owners of the 2018 GMC Terrain filed 225 complaints with NHTSA, most often about service brakes and engine. The maker issued 812 service bulletins for this year. Details by component below, with sources.
Key figures
- Owner complaints
- 225
- involving a crash
- 14
- Technical service bulletins (TSB)
- 812
What fails most often
- 1 Service brakes 37% of all complaints
- 2 Engine 24% of all complaints
- 3 Powertrain 19% of all complaints
- 4 Electrical system 16% of all complaints
- 5 Air bags 6% of all complaints
- 6 Fuel/propulsion system 5% of all complaints
- 7 Forward collision avoidance 4% of all complaints
- 8 Vehicle speed control 4% of all complaints
- Service brakes: 83 complaints (37% of all), 2 of them with a crash reported by the owner; manufacturer bulletins for this component: 25.
- Engine: 55 complaints (24% of all); manufacturer bulletins for this component: 84.
- Powertrain: 42 complaints (19% of all), 2 of them with a crash reported by the owner; manufacturer bulletins for this component: 91.
- Electrical system: 35 complaints (16% of all), 1 of them with a crash reported by the owner; manufacturer bulletins for this component: 181.
- Air bags: 14 complaints (6% of all), 7 of them with a crash reported by the owner; manufacturer bulletins for this component: 6.
Engines and transmissions
US-market versions per EPA. On the right: how many NHTSA complaints name this engine or transmission type.
- 1.5 L · petrol · turbo · 4 cylnamed in 1 complaints
- 2 L · petrol · turbo · 4 cyl
- 1.6 L · diesel · turbo · 4 cylnamed in 5 complaints
- automatic, 6-speed
- automatic, 9-speed
Drive: FWD, AWD
Symptoms owners describe
How many of the 225 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Service brakes | 83 | 2 | 25 |
| Engine | 55 | 0 | 84 |
| Powertrain | 42 | 2 | 91 |
| Electrical system | 35 | 1 | 181 |
| Air bags | 14 | 7 | 6 |
| Fuel/propulsion system | 12 | 2 | 8 |
| Forward collision avoidance | 8 | 1 | 9 |
| Vehicle speed control | 8 | 1 | 2 |
| Steering | 7 | 2 | 15 |
| Electronic stability control | 7 | 0 | 2 |
| Visibility | 5 | 0 | 19 |
| Fuel system | 4 | 0 | 62 |
| Structure | 3 | 1 | 56 |
| Suspension | 3 | 1 | 14 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
The contact stated that the air bags failed to deploy, and the front driver's side seat belt failed to retract as needed. A bystander opened the driver's side door to verify that the contact was safe. The contact noticed that she was bleeding significantly and was unable to move the right shoulder and the neck.
My son wasble to cut the seatbelt and crawl out the window. From what my husband explained (he was the driver), this sounds like what they experienced during the collision. I never received a recall letter from GM as this is something I would of taken care of and have got repaired.
My 2018 gmc terrain brakes did not work when coming to a stop at stop lights which caused me to rear end the car in front of me. There was no warning on my suv nor did I receive a recall on this matter. This happened twice to me in this same vehicle where the brakes did not respond at a low speed causing an accident.
The contact stated that she did not noticed any warning lights illuminated because the failure occurred fast. The contact did not sustained injuries. A police report was filed. The vehicle was towed to don moore chevrolet buick gmc, 3232 villa point, owensboro, [ZIP] [phone], but was not yet diagnosed or repaired.
However when you press the gas again the car jumps into gear causing the steering wheel to jerk either left or right. It either revs too high or it feels like it downshifts.
The first truck struck the front bumper at the headlight & skid all the way down the side of the vehicle then the other truck was slammed into the side of my vehicle. All the damage was on the driver side of the car. My car was moved over into the next lane but no air bags went off.
Screen went black and warning chimes and seat vibration did not go off when backing up. Had to file a claim with insurance to fix my dented bumper. I also experience issues with the audio buttons on the steering wheel.
To his dismay the air bags did not deploy. Luckily he had his take home radio in the car to call for immediate assistant. We were not aware of the recall until we received the onstar june diagnostic report on june 19, 2018 and then a phone call on june 20, 2018 from gmc haggerty to schedule service for the recall.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
Comparison
By complaint count this model year ranks 290 of 2,102 model years in the NHTSA data (top 14% most complained about).
On average one model year of the Terrain has 94 complaints (12 years in the data). This year has 225, above average.
What to check before buying
- Service brakes. Pedal feel, ABS operation, leaks, discs and hoses.
- Engine. Cold start, unusual noises, oil leaks and engine codes.
- Powertrain. Shift quality under load, harsh shifts, transmission codes, CV joints.
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
Manufacturer service bulletins
Bulletin titles as filed with NHTSA.
- This PI provides Diagnostics tips on how the LIN bus works and how to diagnosis it
- This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance
- PI to help diagnose A/C concern
- This preliminary information communicates information about how to determine if a wheel and tires size…
- This preliminary information discusses a condition that may arise from the drivers window switch sending…
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.
- This Preliminary information communicates the steps on how to save a GDS2 Session Log and upload to a…
This Preliminary information communicates the steps on how to save a GDS2 Session Log and upload to a Technical Assistance Case in CX Connect.
- This service bulletin provides information on Tire Sidewall Irregularities
- This service bulletin provides information on replacing the intake manifold when the engine is replaced…
This service bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage.
- This Preliminary Information communication provides information to the technician about vehicles that have…
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…
- The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle…
The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
- New Vehicle Monitoring Programs Section in IVH
- This preliminary information advises technicians the heater hose clamps are one time use only
NHTSA lists 812 bulletins for this year; the 12 newest are shown here.
Other years of this model
Questions and answers
What are the most common problems with the 2018 GMC Terrain?
Owner complaints to NHTSA most often mention: service brakes, engine, powertrain. Total complaints: 225. The most frequent symptoms in complaint texts: warning lights, check engine (25%), infotainment or screen glitches (7%), jerking, harsh shifts (6%).
How many service bulletins (TSB) were issued for the 2018 GMC Terrain?
NHTSA lists 812 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2018 GMC Terrain from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2018 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-04.