We purchased our 2024 GMC Terrain on April 13, 2024 and on June 12, 2024 my husband and I were headed out to go to dinner and when leaving our neighborhood I noticed a weird transmission shift or slip and then the vehicle rpms increased suddenly. I pulled off the road and put the vehicle in park then I attempted to put the vehicle in reverse. The reverse lit up and just began to blink in the dash but the transmission did not go into reverse. I was able to put the vehicle in park and then drive to return home (we were less than 1/4 mile from home thankfully). Luckily we live in rural area and there were not many people on the road. Had we been on a busy road this could have been a dangerous situation. The next day the car was towed to the nearest GMC dealership. The original diagnosis was that the TCM was bad and needed to be replace and that there would be an estimated wait time of about 7 weeks. The TCM was replaced but did not resolve the issue. At that point (July 30, 2024) GM released a bulletin regarding a bad snap ring condition. The service dealer torn down the transmission and determined the snap ring was bad and they also noticed that the clutch was severely burned and needed to be replaced along with both valve bodies. By the time the parts came in and these repairs were completed, we were without the vehicle for 12 weeks. The vehicle was returned to us on 8/21/24. Unfortunately on 8/26/24 - 5 days and approximately 196 miles later, the vehicle began to behave the same way and had to be returned to the dealer. At this point we requested that GM buy the vehicle back from us which they very promptly declined. The transmission was completely tore down again and it was determined a seal or ring needed to be replaced. That repair has not worked either. Now more than 2 more weeks have passed and we are now waiting on a complete new transmission. We have again requested GM but the vehicle back from us. We are waiting on their response.

- Piney Point, MD, USA

Bought new car August 16th 2024. Few days later, I was turning left at a light and the car lost power as I was turning and error messages came up on the dash screen saying service transmission. I also observed that the cars gear indicator went to Park by itself even though the car was still moving. Pushed the engine start button and car came back on and I switched the gear to Drive. Took car in on the 19th to get looked at. Week later, driving down the city street going 40-45 MPH, car lost power again and car gear indicator switched to Park again, service transmission indicator came up and low fuel indicator came up even though I had over 1/2 a tank left. Took in to dealership on August 26th, 2024. Over this weekend, my wife was driving home from up north at a very busy freeway intersection and the car lost power again and luckily she was able to get over to the shoulder. It took some time but she was able to get the car restarted and made it home. There is something seriously wrong with this particular vehicle where we do not want to even drive it. This car has less than 500 miles on it and has lost power three times in three weeks.

- Farmington, MI, USA

Purchased new from dealership 2024 GMC Terrain 4/2024. On 6/26/24 while driving the vehicle the transmission came apart and the vehicle suddenly stopped and would barely move off of the roadway. Had this happened 2 min prior while at highway speeds in crowded conditions, I can only imagine how many injuries could have occurred. My vehicle had 3800 miles on it. Upon my personal research, I found that this is a known problem with the 2024 GMC Terrains and dealerships across the country are filled with vehicles with the same problem. The dealership admitted to me that this has become "a known issue" and that they currently had 7 others with the same issue. They had my car for 8 weeks and according to my paperwork had to repair it twice as it failed the first repair road test! I filed a compaint with GM and was told "to not believe third party sites". I repeatedly asked why this wasn't a recall and they refused to answer the question. Does someone have to have their brand new transmission blow apart at 80 mph and take out others on the highway before they recall this? GM has issued multiple service bulletins to their dealerships but nothing to the public. I tried talking to the dealership and was belittled and stonewalled. Please recall these vehicles before someone is killed. I was finally given my vehicle back from the dealership today after 8 weeks because of no parts available. I am worried they repaired with the same parts that failed in the first place.I have the repair paperwork for your inspection if you would like to review it.

- Saint Louis, MO, USA

Was driving along and transmission downshifted (?) wouldn't change gears. Tachometer was like a race car. Just went wild. Limped it along to a dealership. They informed us it was probably the transmission. It was determined it was indeed the transmission. They also stated that they had 7 more waiting in the service area waiting for parts to repair. Ours was to be #8. We called the dealer we bought it from, they sent a tow truck and towed it to their service area. Luckily, I wasn't out on the interstate going 70 mph as I would have been in just a few more minutes. Very scary situation as I was in 3 lanes of traffic. It was in town, so traffic wasn't moving fast. I was 2 hours into my vacation. Needless to say, that put a damper on things. Had to rent a vehicle, unpack my vehicle and repack the rental. Oh, and by the was it is a 2024 Terrain with ONLY 2400 miles!

- Scottsville, KY, USA

I was leaving work when my car had trouble accelerating from stop. The engine revved, but the gear would not engage. It happened several more times after I stopped at a light or slowed to get on the highway. It would take a minute or so to engage, and then I could drive the car, but it made it dangerous when trying to merge on to the highway or to make any turns in to traffic. It then happened two more times as I slowed to make turns until my engine light came on as I was turning on to my street. When I finally made it to my house and put it in reverse to back into my driveway, the car wouldn't move at all. I took it to the GMC dealership because it is still under warranty. The next day when I called, they told me a piston shot through the transmission housing which caused a leak of transmission fluid. There is a GM Customer Satisfaction Program release for 2024 GMC Terrains and Arcadias that all have a defect in the transmission housing, which is causing a leak of transmission fluid. I had noticed that, whenever I slowed to make a turn anywhere prior to the engine light coming on, there was some hesitation when trying to accelerate, but I thought it was the design of the transmission and engine.

- Tulsa, OK, USA

ON [XXX] my spouse was driving her new 2024 GMC Terrain in Asheville, NC. When suddenly the car stopped and when was able to maintain control and coast to a safe area. The vehicle was subsequently taken to the dealers service center GMC Asheville, NC (Harry's on the Hill). The diagnosis was determined to be a defective a transmission valve body. In discussion with the dealer service manager he indicated this is a common occurrence with the valve body. Needless to say this defect can be fatal especially during inclement weather, fast speeds, winding narrow mountains roads! As of 15 May 2024, the dealer, GMC nor the manufacturer of the valve body has not provided a replacement part for this vehicle. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- San Antonio, TX, USA