GMC Terrain won't shift problems

Filed Jun 1, 2026 · Electrical, Engine · OH

Transmission wouldnt shift. Sensor in car is causing issue, code is N 202321840

Filed May 13, 2026 · Brakes, Engine · 76,000 miles · MI

The contact owns a 2019 GMC Terrain. The contact stated that while stopped and attempting to turn to exit a highway ramp, he observed a loud banging noise emanating from the engine compartment. An "engine reduced power" message appeared. The vehicle then went into limp mode, and when the brake pedal was depressed, it was stiff as a rock. The vehicle coasted while he continued attempting to depress the brake pedal, and it eventually slowed down. The vehicle was steered to the side of the road and turned off. When the vehicle was turned back on and he attempted to depress the accelerator pedal, the vehicle did not accelerate. The vehicle was taken to his mother's residence approximately 100 miles away in limp mode and parked. The vehicle was not diagnosed or repaired. The contact stated that his brother, during an inspection of the vehicle, removed the vacuum pump and noticed that it was broken with numerous pieces that had gone into the engine. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 76,000.

Filed Apr 20, 2026 · Transmission · GA

While driving the vehicle, the engine light came on, plus message board said service transmission and the engine went into limp mode. We let the car sit for awhile and checked the car. A scan said it was the pressure solenoid A in the transmission. The car sat for a day and the light was off. Drove the car and then it acted up again and now reverse doesn't work.

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 Feb 13, 2026 · Transmission · FL · crash

Vehicle did not go into park when the ignition was turned off. Car started to roll while passenger was getting out of the vehicle as another vehicle was parking beside us. The other vehicle could not avoid our rolling vehicle. Passenger had to quickly sit down to avoid being hit. The next day the vehicle was taken to the dealership, and they could not find anything wrong. They gave us a copy of bulletin#08-07-30-026I. We were not aware of any problems or bulletins being issued prior to the accident. We had repairs of $2,705.71 and don't know what the other driver incurred.

Filed Feb 9, 2026 · Electrical · 140,000 miles · MI

The contact owns a 2020 GMC Terrain. The contact stated that while driving in cold weather at various speeds; moisture accumulated and deactivated the charger, causing the vehicle to go into LIMP Mode and lose drive power. The vehicle was taken to the dealer, who diagnosed the vehicle and determined that the charger air cooler was defective and needed to be replaced. The dealer also wanted to place an air deflector on the vehicle. The contact was informed of a service update for the failure however, the VIN was not included. The vehicle was not repaired. The contact researched and learned that in Canada, the issue was being remedied with a bra apparatus and a thermal wrap for the engine to prevent the failure. The manufacturer was made aware of the issue and confirmed that the VIN was not covered. The contact was waiting to hear from a supervisor. The failure mileage was approximately 140,000. The VIN was unavailable.

Filed Jan 22, 2026 · Engine · KS

around chirstmas, Was driving on the highway and the car threw a "reduced engine power" warning and went into limp mode. Check engine light came on. Car asymptomatic prior. got the code pulled and it said turbocharger under boost. The next day the check engine light went out and car was running appropriately. Took the car on the highway again and the car threw the "reduced engine power" warning and went into limp mode again in the middle of freeway traffic. It is a safety concern due to the engine going into limp mode in the middle of high speed traffic. I easily couldve caused an accident putting both myself and others in danger by the engine cutting the power in the middle of the freeway. The check engine light only comes on while going at freeway speeds. The light will then go out overnight and come back on the next time i go back on the freeway at 70-80mph speeds. I have taken it to one shop which reported an oil leak coming from the turbo both inside and outside and that it needed to be replaced. I have read several different forums of other users of the same year, make, and model experiencing the same issue. the car is only a few years old and the likelihood of a turbocharger being bad is uncommon but a major safety concern considering this happened out of nowhere with no signs or symptoms leading up to this.

Filed Jan 17, 2026 · Transmission · CA

Powertrain System failure while driving, causing complete loss of power on road. The car lacks any accessible manual overrides to put in neutral or turn off parking break. This leaves the car stuck in park with all four wheels locked in the middle of the road in an incident with no safe way to move or tow the vehicle. When attempting to tow car must be dragged, and parking brake continuously engages. Tow attempt took nearly 3 hours to saddle the vehicle in the roadway. Vehicle currently awaiting formal inspection/repair from dealership.

Filed Jan 2, 2026 · Engine, Fuel system · TX

The high pressure fuel pump, the car randomly goes into limp mode and stalls and then when cranking it back up in the middle of 635 it hesitates to start, done this 3 times already

Filed Dec 10, 2025 · Engine, Fuel system · MN

The car went into limp mode while I was on the highway. The car said reducing engine power and then I couldn't go the speed limit I had to drive well under the speed limit and pull off the road as soon as possible. I brought it home and water came pouring out the intercooler after looking online. I found out this is a known issue for this vehicle.