2020 Buick Encore GX engine problems

Filed Sep 26, 2026 · Acceleration, Electrical · KS

While driving my 2020 Buick Encore GX, the vehicle experienced a sudden and dangerous loss of acceleration, immediately dropping into 'Reduced Engine power' limp mode in active traffic, but no other car was Infront or behind my car. A diagnostic scan revealed Diagnostic Trouble Code (DTC) P2138, which triggered the computer's safety override system to cut engine throttle. The official dealer repair invoice confirms a manufacturing and assembly defect covered under GM Technical Service Bulletin (TSB) #07-06-04-019G. The technician located water intrusion Panel/Body Harness Connector X112. The root cause was an improperly seated weather seal from the factory, which allowed moisture to short-circuit the accelerator pedal sensor voltage lines. The shop had to reposition the factory seal and apply dielectric grease to the terminals to correct the defect, for which I was charged out of pocket. This manufacturing defect caused a sudden, unpredictable loss of vehicle power on public roads, creating a severe rear-end collision hazard.

Filed Sep 14, 2026 · Engine · MD

There was no service engine warning light on my dashboard. Pending codes in the pictures below popped up on my diagnostics tool less than 24 hours after buying the vehicle from an Audi Dealer. The engine went into limp mode as you can see from the picture below that shows Engine Power is Reduced. After researching these error codes, I was made aware that this is a common issue on this vehicle ad is should be a recall as it states the engine failure is a very serious issue, especially if it occurs while driving. This could cause fatal accidents.

Filed Jul 22, 2026 · Electrical, Engine · IL

I am submitting this complaint regarding several serious mechanical and electrical issues with my 2020 Buick Encore GX that raise significant concerns about the vehicle's reliability and safety. Most concerning, I was recently informed by the dealership that my vehicle requires another transmission replacement, despite having the transmission replaced in 2024. I was also advised that I would need to pay for an additional diagnostic inspection because technicians discovered oil leaking through the lines, which appears to have contaminated engine components. According to the dealership, metal particles have been found within the engine, causing it to malfunction. They have stated that they are unable to determine the source of the contamination at this time. In addition to these major mechanical concerns, I am experiencing several electrical and system malfunctions, including: The passive keyless entry system does not consistently unlock the doors using the exterior door handle, even with a brand-new battery installed in the key fob. The vehicle repeatedly displays a "Shift to Park" warning even though the gear selector is already in the Park position. The vehicle continues to display brake-related alerts and notifications indicating that the brakes need to be serviced or replaced, despite having brand-new brakes installed. These ongoing issues have resulted in repeated repair costs, loss of confidence in the vehicle, and concerns about my safety while driving. The transmission failure occurring shortly after a previous replacement, combined with unexplained engine contamination and persistent electronic malfunctions, suggests there may be underlying defects that warrant further investigation. I respectfully request that these issues be thoroughly investigated to determine whether they are related to known manufacturing defects or warrant a safety recall or other corrective action. I also request that Buick review my repair history and provide appropriate assistance.

Filed Feb 17, 2026 · Engine, Transmission · TX

2020 Buick Encore GX; pulling out of a service station, my check engine light illuminated, and message on cluster stated: Engine Power Reduced. I loss throttle response for accelerating. Accelerator pedal was pushed to the floor and no acceleration. Vehicle entered limp mode. Drove 15 miles from service station to my home, in limp mode, unable to accelerate. Called a technician mechanic who check for Diagnostic Trouble Codes; DTC P0299 Turbocharge/Supercharge "A" Under boost condition; is Confirmed, Pending, and Permanent code. Loss of power to Power Train, unable to accelerate.

Filed Oct 22, 2025 · Engine · 51,220 miles · CO

The contact owns a 2020 Buick Encore GX. The contact stated that while driving at an undisclosed speed, the vehicle began to shake with abnormal sounds coming from the engine compartment. The check engine warning light was illuminated. The vehicle was taken to the dealer, where it was diagnosed and it was determined that the turbocharger had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and referred the contact to the dealer for further assistance. The approximate failure mileage was 51,220.

Filed Feb 26, 2025 · Acceleration, Brakes · LA

I was at a stop light and the light turned green, I preceded to press the accelerator, I was just starting to move forward and the, peddle seemed to take over with my assistance went all the way down and began speeding up. I tried breaking and the car just kept going and not wanting to slow down and kept gaining speed, I had to put car in neutral and turn engine off. Same day, same trip about 4 miles down the road, I began to slow down (35mph) due to a turning vehicle and when I was clear to accelerate once again, it happened again, again, I tried the breaks, and the car kept fighting the break and kept gaining speed, once again I had to put the car in neutral and turn off the engine, the speeds reached 65 mph. before I was able to place in neutral and turn off the engine. No warning lights, car ran normally until those terrifying moments, no check engine lights on before or after the above experiences. My husband and I's safety was put at risk due to the road's travelers and Deadmans curves and cross sections, it put us at risk with a higher chance of crashing into a vehicle or accelerating before being able to make a turn safely. As soon as I made it home, I called the Buick service center and delivered the car the following morning to the service technician. It is at the Ross Downing Service Station today.

Filed Jan 19, 2025 · Brakes, Engine · CA

This is a new issue. Upon exiting my car last night. My car would not shift into park. Everytime I cycled the engine and shift to different gears then park. The car stated it need to be shifted into park still. Without it being in park The car could possibly roll down the hill. Also without it being able to be shifted into park. It continued to flash and keep lights and warning sign on. If not being able to shift into park. I could not leave my car until it recognized the car was in park. The car battery would have drained.

Filed Dec 16, 2024 · Acceleration, Engine · MN

My vehicle is undrivable. Multiple times per trip the check engine light comes on and I see multiple messages come on the driver information center. These are: Service ESC Reduced Power Service Adaptive Steering System The codes that come up are: P0089 for low fuel pressure P00C6 This results in an immediate speed reduction nearly causing multiple collisions with people following me on the highway. As a result I have been using a code reader to clear the codes so i can continue driving. I refuse to drive on busy highways so I am always forced to drive back roads. This needs to be figured out ASAP!

Filed Sep 25, 2024 · Engine · 60,000 miles · OH

The contact owns a 2020 Buick Encore GX. The contact stated while driving at various speeds, the vehicle lost motive power while depressing the accelerator pedal. The check engine warning light was illuminated. The vehicle had been taken to the dealer on several occasions, and several repairs were performed on the vehicle. The contact stated that the turbo was replaced twice; however, the failure returned after the repairs. The vehicle remained in the possession of the dealer for a month and the dealer determined that the mechanical outline was incorrect, and that the turbo had been installed incorrectly. The manufacturer was notified of the failure but offered no assistance. The vehicle was repaired; however, the contact expressed concern that the failure might occur again, and was fearful of driving the vehicle. The failure mileage was approximately 60,000.

Filed Jun 22, 2023 · Engine · WA

I was driving on the interstate on June 7, 2023 heading to work doing the speed limit of 60 MPH and all of a sudden the check engine light came on and a message stated "Engine Power Reduced" and the engine literally dropped engine power immediately and thankfully there was nobody right behind me and I was able to get off the interstate to a safe place. I called the Buick GMC dealership where I purchased the vehicle and they said to bring it in. They pulled codes on it and it gave a code of "engine under boost" and they said they ran tests on it and could not find anything wrong after 3 days at the shop, they did a software update and told me to come and pick it up. Then not even a week later, I was driving and out of nowhere came the same engine light, message read "engine power reduced" and the engine lost power immediately and I called the Buick GMC dealership again and they said to bring it back in and it's there now. I called today to check in and they said they are going to test the Turbo on it and order parts, etc. but they still do not have a definitive answer as to what's wrong with it yet. I bought my 2020 Buick Encore GX new in November 2020 and it has about 26,000 miles on it. No recalls have been made on my VIN model - I am afraid to even drive this car again and get stuck somewhere away from help or at night - someone could have rear ended me when I lost power on the interstate doing 60 MPH and killed me!!!