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 2012 Hyundai Sonata owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2012 Hyundai Sonata. The contact stated that while driving at 45 MPH, the the passengers side tail light failed. No warning light was illuminated. The vehicle was driven to the independent mechanic where it was diagnosed that the tail light needed to be replaced. The vehicle was repaired however the failure reoccurred and was taken back to the independent mechanic where they stated the harness had melted and advised that he go to the dealer. The vehicle was taken to the dealer where it was confirmed that the passenger's side tail light harness was charred and deformed. The vehicle was repaired but the failure reoccurred. The vehicle was taken back to the dealer for a second time where it was informed that the harness or housing had been scorched and the tail light socket melted. The vehicle was repaired. …
B pillar separated from the frame during collision causing catastrophic intrusion into the cabin upon impact leading to death of the driver. No other occupants in the vehicle. Multiple investigators noted the B pillar failure upon inspection. Independent, certified crash reconstruction expert also noticed immediately that the B pillar had failed which caused cabin intrusion to an extraordinary degree considering the 2 vehicles involved were going less than 40mph. Vehicle is available for inspection. In addition, edr data reveals that although throttle was engaged, rpm's remained at idle up to the time of impact. Driver pushing on the gas and vehicle not responding.
The contact owns a 2012 Hyundai Sonata. The contact stated while driving 70 mph, the accelerator pedal was depressed however, the vehicle failed to respond. The vehicle decelerated independently with the Electronic Stability Control warning light illuminated. The contact was able to drive to the residence. The vehicle was not diagnosed or repaired. A dealer was not contacted. Upon investigation, the contact associated the failure with NHTSA Campaign Number: 15V759000 (Exterior Lighting) however, the VIN was not included in the recall. The manufacturer was not informed of the failure. The failure mileage was approximately 141,000.
After the recent recall repairs, the car started to intermittently getting a message on the dashboard saying 'Hybrid System Warning - Safely stop and do not drive' and 'Check brakes' and the brake lights came on with a loud chiming beep, the car would stop accelerating and would not go beyond 10 mph, also the breaks would fail to apply correctly and made a loud screeching sound when applied. It used to do have this issue without any warning, while driving or stopped at the light, without any distinguishing pattern. However, it used to go away when the car was restarted multiple times. However now the message is on continuously and doesn't go away with the restarting the car. After taking to the dealership, they said that the repairs would cost $3000 as the Hydraulic Power Assembly unit has failed. …
I purchased my 2012 Hyundai Sonata on 4-7-22. The car has had no mechanical work, no accidents and has less than 1000 miles. On 9-16-22 i was driving my car home and was less than five minutes away on the highway. My car began to decelerate, I attempted to stop at a red light but my car would not give me control and the brake was rock solid and would not push down. I also could not turn the car off via the start button as the car would not let me. My engine ESC light came on the dashboard in red and the engine completely halted. To get to safety as i was on the highway with oncoming traffic i steered the car to the right on the ramp .I exited the vehicle as it began to smoke ,i thought it would catch fire so i moved far away and called my boyfriend for help and a tow truck to get the vehicle. …
The contact owns a 2012 Hyundai Sonata. The contact stated that while her daughter was driving at undisclosed speeds, the vehicle was jerking abnormally. The passenger's side front tire was extremely hot. The contact stated that the RPM increased to high, and the vehicle lost motive power while driving. The contact stated that while the accelerator pedal was depressed, the vehicle was slow to respond. There was an abnormal electrical burning odor detected. The vehicle was hard to start. The contact stated that the check engine and ABS warning lights were illuminated. On several occasions, the vehicle was taken to the local dealer, who was unable to retrieve any DTC trouble codes. The bearing was fine but was replaced at the owner's request. The mechanic test-drove the vehicle for five hundred miles but was unable to duplicate the failure. …
Daughter was driving her car on interstate, doing 75, in the middle of traffic when the car would jerk and then loose power. The gas petal stopped working and the check engine light would come on. She had to make her way over to the shoulder, without causing an accident. Once car gets shut off and you wait a few minutes, you can start it and drive it home. This has happened about 4 times now. We are lucky that this hasn't caused an accident! This last time (yesterday), the check engine light stayed on and we were able to hook up the dianostic reader and it read the code for the crankshaft positioning sensor A circut. It says online that this is a common problem with that car and is very dangerous. How is this not up for a recall? My daughter is scared to drive her car.
Driving in traffic in town and accelerator pedal quit working. Deceleration happened until I went from 40 mph to 2mph. Then able to accelerate back up to 30mph and happened again until I coasted to a stop. Traction control light came on after second incident. Car was in park and still on. Turned car off, took key outside vehicle and exited vehicle. Car locked itself and brake lights came on and stayed on. This is a danger!!! Can cause an accident, driver has no control over vehicle at random times. Traumatic and scared to drive vehicle now.
When I start the vehicle in the morning I leave the neighborhood going around 15mph and the car loses power. I have to let off the gas completely then reapply but it still continues to studder. I applied the slapstick sift mode and noticed it does this in first and fourth gear. In automatic you can't see it
Approx july 2022 My sonata began to malfunction, first the steering wheel buttons stopped working intermittently off and on unable to turn on and set cruise control, unable to use hands free phone options as well as unable to navigate cluster features, as the time goes on the problem gets worse and eventually do not function ever. I replaced the steering wheel buttons which fixed the issue temporarily only now the vehicle will engage cruise control, accelerate dramatically and continue to gain speed. I am unable to disengage cruise control via the brake pedal, or cancel option or steering wheel. If I depress the brake pedal it will begin to decelerate but once I let off the brake pedal the engine will revv high and gain speed again. …
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 2012 Hyundai Sonata?
NHTSA has 84 complaints about the speed control & acceleration of the 2012 Hyundai Sonata, 5% of the model year's 1,558 complaints. The component named most often is accelerator pedal (4 mentions).
Is there a recall for 2012 Hyundai Sonata acceleration problems?
No. NHTSA lists no speed control & acceleration recall for the 2012 Hyundai Sonata, though it has 8 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 2012 Hyundai Sonata acceleration problems start?
Half of the complaints with a recorded mileage happened before about 57,000 miles, and 27% before 25,000 miles.
Is it dangerous?
Owners linked 9 crashes, 0 fires and 2 injuries and 1 death 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.