2018 GMC Terrain: stuck in gear or won't shift

Filed Feb 25, 2026 · WI

Vehicle will not shift out of park, despite replacing the valve body, putting in a new battery, and transmission fluid. It has been this way since mid January. The codes don’t make sense and there is no current recall, nor have we had this vehicle for very long. It has 48,000 miles on it and is having this issue. Very disappointed.

Filed Jul 9, 2025 · Engine · AR

Broken piston land and ring. car went into 'limp mode' while driving on interstate. Taken to dealer, told new engine was needed.

Filed Dec 3, 2023 · Brakes · GA

While driving down the road at approximately 55 mph, came up to an intersection, 4 Lane I was in the right lane to go straight, there was a right turn lane next to me. I applied the brakes, pedal was really stiff and very slow to respond, I was able to edge over into the turn lane cutting people off and just barely missing the vehicles in front of me. It took 5 car lengths to stop my vehicle. When I finally was able to get the vehicle fully stopped I was almost in the paths of the crossing traffic.. when the light turned green I was able to slowly cross the intersection looking for a safe place to pull over. Immediately crossing the intersection the Service Brake Assist notification appeared, about another half mile the vehicle informed me of loss of power and that it was reducing engine power (limp mode). I was able to find a gas station parking lot to put it. When I opened the hood I noticed quite a bit of engine oil located under where the brake assist pump was located. I had lost about 1.5 quarts of oil. I refilled that. The next day I returned with a tow dolly. The vehicle was started just long enough to load and unload it at home. We pulled the vacuum pump where upon inspection it was noticed that the part has exploded and so far we are still missing some pieces that may be inside the engine. This is a known and documented problem of this part and should have a safety recall issued. . I still owe over twenty eight thousand on this vehicle and it has only 109,000 miles on it. I hope we can find all the pieces and that the engine wasn't fately harmed. GMC needs to make this right, a lot of people could have been harmed.

Filed Oct 3, 2022 · Acceleration, Engine · TX

When driving the car at low speeds, or right after having been stopped for a few moments. Upon, acceleration, the car will sometimes go into a limp mode. On the DIC, will be displayed a warning about how the car will have the speed reduced after 175 miles and to check the emissions system. The speed has already been reduced at that point. Also displayed maybe a warning about how the power has been reduced. USUALLY, if I turn off the car and wait about a minute, I can restart the car and drive at a normal highway speed again. But not always. The warning on the DIC, will usually turn off if the car does return to normal speeds after about 5 - 10 miles. However, the check engine light may still stay on for several days. This problem can be a daily occurrence. I've had the car in the shop several times, and they have been unable to fix the problem. The car can be unpredictably unsafe, when speed is instantly reduced to 30 mph!

Filed Sep 10, 2020 · Transmission · 18,500 miles · PA · crash

The car keeps revving and doesn't shift into gear. You have to lift your foot off the gas pedal and give it a few seconds and them press it again. 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. This last time, 9/8/20, I just reversed out of my driveway onto my residential street, going about 18 MPH when the car would not shift into 2nd gear. When it jerked into gear it jerked the steering wheel and it caused me to hit a parked car just 4 doors down from my house, causing $6000 worth of damage to my terrain likely totaling the 2010 corolla I hit. I have had a clean driving record for 30 years until now. Gmc will not own fault and now my insurance will go up as well for something that really was not my fault.

Filed Apr 8, 2019 · 680 miles · OH

Transmission locks up and will not shift into higher gear. This has happened several times while driving.