2020 Hyundai Sonata: hesitation when accelerating

Filed Feb 20, 2026 · Engine, Fuel system · FL

On 2/19/2026 while driving, my 2020 Hyundai Sonata Limited 1.6T began making several loud explosive / popping sounds. At the same time, the fuel gauge on the display screen appeared to rapidly drop, as if the vehicle was losing gas. Immediately following this, the vehicle began to hesitate and lose power while accelerating. The hesitation felt like the engine was misfiring or struggling to maintain consistent performance. There were multiple explosive sounds before and during the hesitation. This created a major safety concern while driving and the vehicle underwent an inspection at Hyundai in Deland, FL. The service department was brief and stated they needed to keep the vehicle for repair for an unknown amount of time as the fuel tank expanded. No further information was provided at that time.

Filed Sep 10, 2025 · Engine, Transmission · 101,000 miles · MS

The contact owns a 2020 Hyundai Sonata. The contact stated that the vehicle hesitated while depressing the accelerator pedal, with the check engine warning light illuminated on the instrument panel. The vehicle was taken to several independent mechanics and dealers to be diagnosed; however, the cause of the failure was not determined. The contact stated that one mechanic replaced an unknown sensor, but the failure returned soon after the repair. The manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was approximately 101,000

Filed Aug 7, 2025 · Transmission · NY

My certified pre-owned 2020 Hyundai Sonata has experienced the same critical transmission failure three times since October 2024, creating dangerous safety conditions on highways and city streets. Component/System Failed: Transmission control system with consistent P0768 error code (Shift Solenoid D Circuit Fault). Safety Risks: The transmission failures cause sudden power loss and inability to accelerate while driving, including on highways at speed. This creates immediate danger to myself, passengers, and other drivers when the vehicle unexpectedly loses power during traffic situations requiring acceleration or merging. Problem Reproduction: The failure has been confirmed and reproduced by authorized Hyundai dealership three separate times: - [XXX]: P0768 error, replaced shift control solenoid valve - [XXX]: Same P0768 error returned, replaced entire transmission control unit - [XXX]: Same P0768 error again, replaced complete control wiring harness with extensive dashboard removal Warning Signs: Each failure was preceded by transmission hesitation, rough shifting, and check engine light activation before complete power loss occurred. Manufacturer Inspection: Hyundai technical assistance case #[XXX] was opened for the third failure, acknowledging the recurring nature of this defect despite multiple repair attempts. Assessment: This appears to be a systematic manufacturing defect in the transmission control system affecting safety. Despite three different repair approaches by Hyundai, the identical P0768 error continues to recur, suggesting a fundamental design or manufacturing flaw that creates ongoing safety risks for drivers. The vehicle was out of service for 44 total days across these three incidents, indicating the severity and complexity of this recurring safety defect. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jan 4, 2025 · Engine, Fuel system · VA

Been having an issue with a check engine light and a popping noise in the from the front of the vehicle for about two years. Took it to the dealership more than 3 times over that span and every time they discovered it was caused by something different..during the July of 2024 while driving on the interstate a loud pop noise was made from the back and my children complain about the seat lifting…shortly after I went to get gas and a full tank was more gallons than usual 14 increased to 17g…. I once again took it to the dealer for the issue of the gas tank expansion and pop but found nothing. No more than a week later my car would hesitate to accelerate and progressively got worse. On 12/27/24 I took it to the dealer and they discovered my gas tank was expanded and was unsafe to drive leaving me without a vehicle.as of 1/04/2025 I still have no solution.

Filed Aug 25, 2022 · Electrical, Transmission · 19,000 miles · MI

The contact owns a 2020 Hyundai Sonata. The contact stated that while her husband was driving 75 MPH, the brake warning light appeared on the instrument panel as the vehicle began to hesitate upon depression of the accelerator pedal. The contact stated that the vehicle decelerated to 20 MPH as her husband pulled to the side of the highway and turned off the vehicle. The contact called the dealer and was given suggestions on how to correct the failure; however, none of the options worked. After some time, her husband restarted the vehicle and the vehicle resumed normal operation. The next day, the contact stated that the brake light returned upon start of the vehicle. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 19,000.