Owner-reported complaints naming the engine system, filed with NHTSA
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Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components. Every record below is an owner-reported complaint about the 2021 GMC Terrain submitted to NHTSA — not a confirmed defect, not a recall and not a manufacturer bulletin. 9 reports on file name it.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Shown in the owner’s own words, exactly as filed
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
The contact owns a 2021 GMC Terrain. The contact stated that while driving at various speeds, the vehicle hesitated while depressing the accelerator pedal, with a misfire coming from the engine. During the failure, the message "Engine Power Reduced" was displayed on the instrument panel. The vehicle was taken to a local dealer, and the contact was provided an estimate for a diagnostic test. The contact declined. The vehicle was not repaired. The manufacturer was not contacted. The failure mileage was unknown.
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.
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.
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 NHTSA Hotline for assistance. The failure mileage was approximately 78,843.
The contact owns a 2021 GMC Terrain. The contact stated while driving at various speeds, the transmission erroneously shifted to the neutral, causing the vehicle to decelerate. After restarting the vehicle, the vehicle operated normally. During the failure, the message " Power Reduced" was displayed. The cause of the failure was not yet determined. The local dealer was notified of the failure. The vehicle was not repaired. The manufacturer was not contacted. The failure mileage was 36,000.
The contact owns a 2021 GMC Terrain. The contact stated while driving 5 MPH, the vehicle stalled. There was no warning light illuminated. The contact stated that the failure was like GM Product Safety Recall: N222372310 (Inadequate Fuel Pump Flow). The vehicle was towed to an independent mechanic, who determined that the fuel pump had malfunctioned and damaged the camshaft. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The approximate failure mileage was 86,000.
I purchased the car August 2024, I have had it for 4 months and while driving down the road a large fuel tank pops up stating low fuel and the car comes to an abrupt stop.The 3x the gas tank was never low. Parking brake comes on and car doesn't not move. All lights on dash come one. It has done it 4 times and thankful each time I was in a 30 mph zone. If I was going 55 I am sure the result would have been bad. The car last did it on December 29, 2024 and has been in the dealership for 3 weeks now and they cannot fix it. I told them 3 days into my purchase I wanted a full refund and they denied me. ?? I had that right I am still fighting with them to take it back because one of these times I am going to get in a bad accident. I don't feel safe in the car and I told them each time.
The car has revved high rpm's since purchase, with multiple attempts to get it resolved . Since then, the steering wheel has jerked out of my hand's multiple times, unexpecting, causing the car to jerk while being stopped. The car has also not budged in the middle of traffic while being in drive and the pedal down to the floor until at least a 10 second delay and when doing so the screen that includes the radio, etc panel has completely blacked out and started twitching
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Categories with enough reports to have a page of their own
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