2026 GMC Terrain owner complaints

I was driving (roughly about 30 MPH) when my automatic braking kicked on and caused my tires to squeal to a halt. There were no other cars around me (thankfully) - otherwise I would have been rear-ended. Right before it stopped, it flashed the warning lights for a quick second. I wanted to report this issue in case others are experiencing the same problem and to hopefully help prevent it from happening to someone else. Very scary and could cause a serious accident. I turned off all of my automatic brake settings after the incident, as I believe it is faulty and don't want to risk it happening again.

I have brand new GMC Terrain 2026, I leased dog on Aug 4th 2025. After one week into driving the vehicle, OnStar, GPS NAV stopped working and the Emergency calling is not working. All features related to locating the vehicle through OnStar or through google stopped working, in addition to SoS not working. I took it to the dealership they said the Telematics module needs replacement.

The Screen calls my own phone number and hangs up over and over if I just ended a call. I am not able to use any part of the screen afterwards such as my map. It stays like that until I disconnect the Bluetooth and wifi from my phone while trying to drive. Safety issue!

Two issues here. First is that the car will give a danger warning when nothing is there. Sometimes goes as far as slamming on my breaks. Both in drive and reverse. Second is the lane keep assist. It’s like it is working backwards. I turned this all off because it would jerk me out of the lane and into the other lane or off to the sides of the road.

I bought this car new from Davidson's in Rome, NY in early March 2026. This is a 2026 model. Two days after I took possession, I noticed that the spare tire well was halfway full of solid ice. The car has a severe leak through the back right side window. The dealer states it needs to be replaced. The interior frames of the car were loaded with water for many weeks as it stood on the lot. Had the dealer done a final inspection of this car prior to transferring ownership to me, as they should have and stated they did, they would have found the solid ice that surrounded the spare tire and investigated the leak and repaired it BUT they would have been required to tell me of this leak I assume...if so, I would never have bought this car. They had the car in the shop now for 3 weeks as of

Car was off and parked and randomly caught on fire. Completely totaling the car

Purchased NEW 2026 GMC Terrain Elevation, and it came with NO User Manual. I was told by the dealership (Al Serra GMC in Grand Blanc Michigan that i could either purchase one for $50.00+ dollars, PLUS TAX & $25.00 SHIPPING, or d/l it via the infotainment system in the car, WHICH DID NOT WORK! Talk about [XXX] A VIETNAM VET!!! We are both [XXX] old & need a manual, so bought a reproduction of the original via eBay for $50.00. At least GM could reimburse the cost of the manual… INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Very soon after purchase vehicle developed a front end shake and continued to get worse. This happens when pulling out or in stop and go traffic this varies from in intensity and sometimes it can be quite violent shaking the whole vehicle. The car has been to a GM dealership for this problem 3 times now. The first time 9/8/2025 replaced rear axle, the second time 10/20/25 both front axles were replaced. The 3rd time GM engineer Paul Koerner said they are aware of this problem but there is no repair until it is further investigated this was 12/10/25. As of this time there is still no repair but a bulletin has come out document #7036661. This states the customer should continue to drive vehicle I now have 7600 miles on it and it continues to shake every time I pull out. There seems to be no

This vehicle was bought new and is a NEW 2026 GMC TERRAIN DENALI with less than 5,000 miles at this time. It is a continuous event and not a specific failure date, but began soon after purchasing. The specific parts are UNKNOWN. It could be tires, wheels, steering parts (CV JOINTS, CONTROL ARMS ETC) or possibly transmission. I took it initially to the purchasing dealership and they took it for a ride and just dismissed the problem without investigating. Several days later I called and talked to the person who sold me the SUV and was told either him or service manager or both would call me, but neither did so. They were to set up a return date. After this insulting experience I decided to take it to a Cadillac dealer that I have had great experience with in the past. They took it for a ri

Car aggressively shakes and steering wheel shakes / jerks itself side to side when accelerating. Getting worse with time. GMC has it as a known issue but has been for months. Problem is getting worse the more it is driven. GMC says it is “safe”.

Vehicle “wobble” under moderate acceleration and in corners, can be felt in the seats and steering wheel.

Master cylinder , less then 1000 miles was pulling out of a parking lot and the brakes went out

ABV came on. SCR alerted I needed service. On a 25 mph road I no longer could brake randomly

The contact owned a 2026 GMC Terrain. The contact stated that while her husband was driving on a perpendicular road at an undisclosed speed, entering a highway, the driver yielded; however, a truck in the median was attempting to cross the highway during oncoming traffic, and an oncoming vehicle crashed into that vehicle, causing the truck to crash into the front of the vehicle. The front air bags deployed as intended. The contact stated that an electrical fire started under the center console, and the driver’s shirt was burned by the fire. The Fire Department was on scene and removed the contact from the vehicle; however, a fire report was not filed. An off-duty sheriff witnessed the crash and assisted in removing the contact husband from the vehicle. The driver was taken to the Emergency

The contact owns a 2026 GMC Terrain. While drying the vehicle after it was washed, the contact became aware that the middle section of the vehicle was loose. The vehicle was taken to the dealer. The dealer informed the contact that the part to repair the vehicle needed to be ordered. The contact was awaiting a response from the dealer. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 3,000.

The car has always had an issue where it would just get stuck in a low gear and RPMs would go high. Does this every single day. But recently it also started acting like it was put into neutral for a few seconds and then back into drive.

The contact owns a 2026 GMC Terrain. The contact stated that while attempting to depress the accelerator pedal after coming from a complete stop, the vehicle started wobbling. A dealer was contacted. The vehicle was taken to the dealer to be diagnosed; however, the diagnostic result was unknown. The vehicle was not repaired. The contact associated the failure with Technical Service Bulletin: PIT6466 (Shimmy, Shake or Wobble When Leaving a Stop); however, the VIN was not included in the bulletin. The manufacturer was notified of the failure and informed the contact that there was no recall for the failure, and opened a case. The failure mileage was 5,200.

The vehicle has been taken to the dealership at least 4 times. Each time for the same reason: when driving at 65 or higher, it sounds like it's on a flat. My screen also glitches when foot is taken off the break after a stop. The service advisor told me that there was a shortage of mechanics and asked me to bring it back next week (this is the response I have gotten each time). I have asked for a loaner twice and was told that there were none available. Therefore, I had to pay $40 to uber to work. Today, I said that I couldn't come back because it's the same issue and I have to work next week. He then let me speak to a service manager. The service manager drove it (with me in the passenger seat) and heard the sound. He noticed that it was not all of the time and that my steering wheel was

The windshield has an optical distortion, characterized by "waviness" and "rippling." This condition is not merely a cosmetic imperfection; it is a safety hazard that causes visual impairment, and dizziness while driving. This defect compromises my ability to perceive distances and hazards accurately, especially when looking through the passenger side while making turns or looking for hazards. Current Status of the Issue as reported online Documented reports indicate that GMC dealers are aware of these "warped windshields" and that the issue appears to be a systemic quality control failure in the 2026 model year. • Safety Risk: This distortion constitutes a safety-related defect as defined by the National Highway Traffic Safety Administration (NHTSA), as it interferes with the driver's p

The contact owns a 2026 GMC Terrain. The contact stated that there was an abnormal clunking sound coming from the front driver’s side suspension while driving over bumps in the roadway, and while braking and turning the steering wheel. No warning lights were illuminated. The vehicle was taken to a local dealer, where a test drive was performed; however, the dealer was unable to determine the cause of the failure. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 14.