2026 GMC Terrain problems

Filed Nov 4, 2026 · Transmission · NY

I was at a stop light with auto start stop enabled and when I went to drive again I felt a sudden jolt and car immediately shifted to park while on a main road I was unable to shift until I shut the car off opened the door and restarted it the. Drove like normal but a check engine light appeared and a fault was sent to the app where it then said transmission fault service now

Filed Sep 23, 2026 · Driver assistance · TX

On the evening ofXXX, at approximately 6:00 PM, I was driving this Avis rental vehicle on a highway in [XXX] at normal highway speed, below the posted limit, with my foot on the accelerator. The forward collision warning and automatic emergency braking system activated and applied the brakes hard. There was no vehicle, pedestrian, obstacle, or hazard ahead of me, and no vehicle behind me or beside me. The roadway was clear and dry. The sun was low in the sky, and the vehicle was crossing a metal expansion joint on an overpass at the moment of activation. I believe the low sun angle, the expansion joint, or both caused a false object detection by the forward-facing camera or radar. The service brakes themselves functioned correctly. The failure is in the forward sensing and decision logic, which commanded a braking event with no object present. The deceleration was severe and unexpected. I sustained sharp pain in my neck and shoulder. Had any vehicle been following me, this would have caused a rear-end collision at highway speed. There were no warning lamps, messages, or other symptoms before the event, and none afterward. I had driven the vehicle for seven days with no prior indication of a fault. I exited the highway immediately and drove back to the rental location on local streets at low speed because I no longer trusted the vehicle. I returned it the following morning when the Avis office opened, more than a day early, and reported the defect. Being a rental vehicle it was not available to me for inspection. The rental company has advised that it was taken out of fleet for inspection after my return, that there are no open recalls on it, and that it will not release internal service records to me. I do not know the outcome of that inspection. To my knowledge the fault has not been reproduced or confirmed by a dealer, independent service center, or manufacturer representative. No police report was filed because no collision occurred. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S

Filed Sep 21, 2026 · Acceleration, Driver assistance · OH

a failing telematics module on your 2026 GMC Terrain is causing network corruption, leading to an erratic speedometer and loss of driver assistance systems while driving.

Filed Sep 19, 2026 · Brakes, Suspension · OH

My vehicle is making a squeaky sound/noise when breaking and getting louder. I took it in for service and they couldn’t seem to find the issue. It’s coming from the front end of the vehicle

Filed Sep 18, 2026 · Suspension · MI

Shimmy, shake, wobble, after TSB 26-NA-109 repair, replace front springs, vehicle feels less stable at highway speeds. The initial condition, Shimmy, Shake, Wobble, under moderate acceleration, still exists after last repair attempt.

Filed Sep 14, 2026 · Locks · 2,500 miles · OH

The contact owns a 2026 GMC Terrain. The contact stated that while driving 10 MPH and pulling into a parking lot, the vehicle was shifted into drive(D) and the driver’s door lock unexpectedly unlocked. The contact stated that on another occasion, a passenger in the front passenger’s seat noticed the same failure with the passenger’s side door lock. The vehicle was taken to the dealer, where it was not diagnosed or repaired. The contact expressed concern that the failure was hazardous and posed a safety risk because the doors could open while the vehicle was moving. The manufacturer was not made aware of the failure. The failure mileage was approximately 2,500.

Filed Sep 11, 2026 · Electrical, Transmission · MO

Avis Rental. Vehicle simply shut down while driving and would not re-start. Vehicle could NOT be put into neutral to move from roadway. Emergency services vehicles had to remain on site awaiting tow vehicle. Very dangerous situation.

Filed Sep 1, 2026 · VA

I recently pulled over to help a woman driving a 2026 GMC Terrain who had run out of gas in the middle of XXX in Virginia. Obviously, the first priority was to get the vehicle out of the travel lanes and onto the shoulder. I tried to figure out how to put the Terrain into neutral so we could move it, only to discover that **the vehicle cannot be shifted into neutral if it is not running.** Since it was out of gas, it could not start, meaning we could not put it in neutral and could not move it out of the roadway. Fortunately, a VDOT Safety Service Patrol truck came by. The driver stopped to help and thankfully had gasoline. However, I was told that, according to policy, he could not put gas in the vehicle while it was still in the travel lanes. This created an extremely dangerous catch-22: **the vehicle could not be moved because it could not start, it could not start because it was out of gas, and gas could not be added because it had not been moved out of the roadway.** I believe this is a serious safety issue with the vehicle. A disabled vehicle should have a reliable way to be placed in neutral regardless of whether the engine can start. This is especially important after a breakdown or crash, when the vehicle may need to be moved quickly to protect the occupants, other drivers, or first responders. If there is a manual emergency procedure for putting a completely disabled Terrain into neutral, it should be clearly documented and readily accessible to drivers and roadside assistance personnel. If there is no practical method, I believe GMC needs to address this design. A modern vehicle should not become an immovable roadblock simply because it ran out of fuel. Please investigate this issue and take whatever action is necessary to ensure disabled vehicles can be safely moved out of active traffic lanes.

Filed Aug 30, 2026 · Driver assistance · NY

When starting to accelerate from a red light. The car in front of us was accelerating faster. Yet our car initiated an emergency braking action at around 15 MPH. It was very jarring and I still have a headache more yhan 1 hour after the incident.

Filed Aug 23, 2026 · Driver assistance, Electrical · OH

Subject: Urgent: Unresolved Ongoing Vehicle Issues - Request for Contact ​To Whom It May Concern, ​I am writing to express my strong frustration regarding ongoing and unresolved issues with my vehicle. Ever since I purchased it, I have been plagued by constant alerts regarding various vehicle failures. ​My vehicle has already been reset and updated twice to address these issues. I just picked it up after it was supposedly fixed at the dealership this past Thursday. However, today, Sunday, [XXX], the exact same warning alerts have started popping up once again. ​This situation is unacceptable, and I need someone to reach out to us immediately to discuss a permanent resolution. Please contact us at either of the following numbers: ​Primary Phone: [XXX] ​Secondary Phone: [XXX] ​I expect a prompt reply to arrange the next steps. ​ INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)