Which parts fail
Components named in complaints (accelerator pedal, throttle, sudden acceleration, cruise control).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2015 Hyundai Sonata owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2015 Hyundai Sonata. The contact stated while driving approximately 3 mph and entering a driveway, the vehicle accelerated independently and crashed into a metal gate. The contact stated no warning light was illuminated. The contact stated no air bags were deployed. The contact stated no one was injured nor sought medical attention. The contact did not contact the police department nor filed a police report. The vehicle was not drivable and was left at the locations of the incident. The vehicle was not diagnosed or repaired. A dealer was not contacted. The manufacturer had not been informed of the failure. The failure mileage was approximately 63.000.
My engine light has been on for over one year. I took it to the dealership to see what was going on and to get an oil change. The dealership stated that there could be a variety of issues and that they would turn the light off and when it came back on to bring it back to them. The staff was not the most professional so I opted to not take it back unless there was a significant issue. My car constantly accelerates when I am on the brakes at a light and then when I let off the brakes, the car accelerates before I put my foot on the gas. I recently backed out of my parking space and without my foot on the gas, I bumped into a neighbor's car. There was no damage to their car but my car has a dent in it. Everyone is safe and fine but this could have been way worse if I was in a parking lot or on the road. The car does not accelerate when I put my foot on the gas on the highway either. …
My 2015 Hyundai Sonata has demonstrated multiple instances of unintended acceleration and braking failure: April 20, 2024 - While idling in a drive-thru line, the vehicle suddenly lurched forward without any attempt to accelerate and crashed into the vehicle in front of me. I was unable to stop it. This resulted in the other car being totaled. I took it to a Hyundai dealership afterward, but they found no definitive cause. April 4, 2025 - My daughter was driving and attempted to stop at a red light. Despite applying the brakes, the car did not stop and continued through the intersection, striking the door of another vehicle. May 12, 2025 - Today, while using cruise control set to 55 mph, the car began accelerating beyond the set speed without input. It appears the cruise control system is malfunctioning and not disengaging as expected. …
The contact's daughter owns a 2015 Hyundai Sonata. The contact stated that while the vehicle was idling, the vehicle hesitated. The contact stated that his daughter had to depress the accelerator pedal to rev the engine. The contact then stated that on a separate occasion while driving at an undisclosed speed, the vehicle hesitated and stalled. Additionally, the contact stated that on another separate occasion while his daughter was driving at an undisclosed speed, the vehicle unintendedly accelerated. The contact's daughter was able to regain control of the vehicle and depressed the brake pedal to stop the vehicle. The check engine warning light was illuminated. The vehicle was towed to an independent mechanic where the vehicle remained. The cause of the failure was not yet determined. The vehicle was not repaired. The manufacturer was not notified of the failure. …
The contact owns a 2015 Hyundai Sonata. The contact stated while driving approximately 30 MPH, the sunroof detached from the roof of the vehicle. The cause of the failure was not yet determined, and the vehicle was not yet repaired. The vehicle also experienced severe engine knocking and the vehicle was taken to the local dealer who diagnosed that the engine was faulty and needed to be replaced. The engine was replaced, and the vehicle was repaired. In addition, several safety features including the Lane Departure, Cruise Control, and the Forward Collision Avoidance system intermittently malfunctioned. The cause of the failure was not yet determined. The manufacturer and local dealer were notified of the failure. The failure mileage was approximately 92,000.
The contact owns a 2015 Hyundai Sonata. The contact stated that while driving 40 MPH, the vehicle failed to accelerate while the check engine warning light was illuminated. The vehicle was towed to an independent mechanic where it was diagnosed that the throttle control module needed to be replaced. The vehicle was repaired however, two weeks later the check engine warning light illuminated. The vehicle was taken to the dealer where it was diagnosed that the Voice Coil Motor (VCM) needed to be replaced. The vehicle was repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 127,828.
The contact owns a 2015 Hyundai Sonata. The contact stated while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. In addition, the check engine warning light illuminated, and the vehicle lost motive power. The vehicle was towed to the dealer where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure; however, the engine replacement request was denied. The failure mileage was approximately 140,829.
The contact owns a 2015 Hyundai Sonata. The contact stated that while operating the vehicle, it would not immediately accelerate when pressing the accelerator pedal. The check engine light would remain illuminated. Also, the vehicle had experienced unintended acceleration. The vehicle was taken to an independent mechanic who reprogrammed the engine software but the failure continued to occur. The local dealer was notified of the failures. The manufacturer was not yet contacted. The failure mileage was 50,000.
I'm really at wit's end with what is going on with my car. My car is currently at 104K, its a 2015 Hyundai Sonata Sport. A beautiful car with an abundance of serious issues. I've had trouble with my car accelerating for over a month and I've taken it to at least 5 mechanics who have troubled shooted with no success to fixing the issue. The problem: my car hesitates significantly when accelerating and sometimes when it's can't shift gears and I'm easing my foot on and off the gas pedal, it begins to shake while attempting to accelerate. I try not to put the car in sport mode but sometimes this mode is what helps the car shift gears but I don't think this good for the car. So far I've tried changing all of my spark plugs and coils replaced, fuel injectors cleaned (dealership), transmission fluid changed and ECM updated (dealership). …
Major oil consumption going on for years. Took in to dealer two years ago, they know there is a problem. They told me I could spend thousands of dollars to tear it apart to find out what is going on, and also told me to call corporate. I got no where with either, even though they recalled the engine in other Sonata cars, just not our ECO model. Slowly started having throttle issues at 4 to 5 year mark. Informed dealer service center that it wasn't moving like it should when gas was pressed. Now, the car is having major problems with acceleration. Barely would go in reverse, drove 1.5 blocks, speed not matching to throttle, press on gas, barely moving from a stop, going really slow, had to turn around and take back home. Our problem with the car is the same that others are complaining about. The car is not safe for a 7 year old car that started having problems at the 4 to 5 year mark.
NHTSA investigations
Throttle control system vulnerabilities
The Office of Defects Investigation (ODI) of the National Highway Traffic Safety Administration (NHTSA) received a petition letter dated October 10, 2021, requesting an investigation of possible defects in the electronic throttle control (ETC) system on certain Kia vehicles resulting in the opening of DP21-003.
Acceleration complaints in other Sonata years
Frequently asked questions
How common are acceleration problems on the 2015 Hyundai Sonata?
NHTSA has 61 complaints about the speed control & acceleration of the 2015 Hyundai Sonata, 5% of the model year's 1,153 complaints. The component named most often is accelerator pedal (2 mentions).
Is there a recall for 2015 Hyundai Sonata acceleration problems?
No. NHTSA lists no speed control & acceleration recall for the 2015 Hyundai Sonata, though it has 9 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2015 Hyundai Sonata acceleration problems start?
Half of the complaints with a recorded mileage happened before about 50,000 miles, and 26% before 25,000 miles.
Is it dangerous?
Owners linked 8 crashes, 0 fires and 3 injuries to speed control & acceleration problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.