2021 GMC Terrain: check engine light

Filed Sep 29, 2026 · Engine · MO

I have had my check engine light come on for P0299. I've lost power while on the road. Had my turbo replaced and now the same issue is starting again. I'm afraid of my car stalling out again with my child in the car. This is a definite safety issue especially since this is happening again months after getting the new turbo put in.

Filed Mar 16, 2026 · Engine · NY

Vehicle went into reduce engine power mode and check engine light came on. Vehicle has just over 60,000 miles. Code is telling me I need a new turbo and being quoted $1,500-$3,000. I have read so many people having the same issue with needing a new turbo just after 60,000 miles

Filed Jan 26, 2026 · Driver assistance, Engine · WI

The engine light came on while driving, saying “engine power reduced”. It barely accelerates, RPMs go over 5, it chugs when driving. Taken to an independent service center.

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 Sep 17, 2025 · Brakes, Engine · 78,843 miles · KY

The contact owns a 2021 GMC Terrain. The contact stated that the transmission was previously replaced. The contact stated that upon starting the vehicle, the check engine warning light illuminated. The failure had occurred intermittently. Additionally, the contact stated that while driving approximately 15-20 MPH and depressing the accelerator pedal, the vehicle failed to respond for approximately 1 minute. The vehicle was taken to the Nissan dealer it was purchased several times. The dealer retrieved diagnostic trouble codes: P057C and P057E, and the brake pedal position sensor was replaced twice; however, the failure persisted. The Nissan dealer took the vehicle to a GM dealer, where the cause of the failure could not be determined. The vehicle was not repaired. The contact related the failure to TSB Number: PIT5994 (Diagnostic Tip for Reduced or Low Engine Power on Acceleration). The manufacturer was notified of the failure and referred the contact to the federal safety agency Hotline for assistance. The failure mileage was approximately 78,843.

Filed May 28, 2025 · Suspension, Transmission · MO

First time I had problems with my 2021 Terrain I took it to victory GMC on 9/20/24. At the it had 45,000 miles. Every time I would drive and accelerate it would shake extremely bad in the floorboard. There was also transmission fluid leaking. I picked the car up on 9/27/2024 and was advised that both front axles were replaced, which corrected the shaking and the driver side axle seal was replaced, which was where the leak was coming from. this was covered under warranty but at 45,000 miles I should not have been already having axle problems or any type of leak. I dropped my car off again on May 5, 2025. When I called them the day I made the appointment I let them know I had a service transmission message show up and then go away, I told them it’s taking longer to kick into gear when I’m on the highway, I told them it revs up past 4 1/2 RPMS at times when it had not previously done this and it just sounded like the engine is working harder. I also told them I had a check engine line come on and go off and it was code P2271 which was an oxygen sensor code. I also told them when I had the oil changed. They told me there was a slight oil cooler leak starting. All this was supposedly addressed when I dropped it off to be serviced on 5/5/25. I was called on five 625 to pick up my vehicle notifying me that they found no issues. They were unable to verify concern concerning my check engine light. They said there was no oil cooler leaking, it was just slightly seeping, so not considered a leak. And they said no transmission concern operated as designed. Fast forward to May 9, 2025… I got in my car in the morning and once again the check engine light was on. I drove it straight to GMC and had them put the reader on it. The oxygen sensor code came on. The same code I told them about on the 5th that they said was fine on the 6th. I made an appointment once again to get this check engine light looked at although the check engine light is not on at the moment again.

Filed Sep 6, 2023 · Fuel system · 25,000 miles · OH

The contact owns a 2021 GMC Terrain. The contact stated upon pressing the Push to Start button, the vehicle failed to start after several attempts, and the battery drained. The vehicle was towed to the dealer, but the failure could not be duplicated. The contact stated that the vehicle restarted after a while. The check engine warning light was illuminated. The contact stated that the failure recurred intermittently. Additionally, the contact stated that the vehicle stalled while at a complete stop at a traffic light. The contact also stated that the vehicle stalled while driving on two separate occasions. The contact was able to veer to the side of the road. On one occasion, the vehicle restarted after several attempts and was driven to the dealer; however, on the other occasion, the vehicle failed to restart and was towed to the dealer. The dealer diagnosed the vehicle but could not determine the cause of the failure. The vehicle was taken to an independent mechanic, where it was diagnosed that the fuel pump control module needed to be replaced. The vehicle was repaired; however, the failure persisted. The contact related the failure to the federal safety agency Campaign Number: 23V013000 (Fuel System, Gasoline); however, the VIN was not included. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 25,000.