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 2017 Hyundai Sonata owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2017 Hyundai Sonata. The contact stated while driving 25 MPH, the accelerator pedal was depressed seized on the floorboard. The check engine warning light illuminated. The contact stated that the vehicle failed to exceed 25 MPH while driving. The contact veered to the side of the roadway, turned off, and restarted the vehicle; however, the failure recurred while driving. The dealer and the manufacturer were not notified of the failure. The vehicle was not diagnosed or repaired. The approximate failure mileage was 66,000.
Vehicle's engine began to emit a knocking sound that would increase in volume and speed as engine progressed in speed. Engine suddenly lost power, check engine light began to flash and traction control disabled itself. Vehicle was pulled over and turned off when it immediately began to rapidly self immolate over the course of minutes while the power to the engine was completely disabled.
The vehicle has twice been disabled while driving due to "lost communication with hybrid module powertrain control module." This breakdown is a significant safety hazard as the car loses power and coasts to a stop without any warning. The second time was on a 65 mph highway. Neither time has had any warning before the malfunction lights appeared. The first time occurred on 10/7, and the vehicle was towed to the dealership. Nothing was done besides clearing the trouble codes and test driving with the car, which returned at the end of October-the second time the breakdown occurred about a month later on 12/3. This second time, I removed the code myself on the roadside so as not to be in more danger, and I am currently awaiting an update from the dealership's service department on their next steps after initially being told to just have it towed in again. …
I am leasing a 2017 Hyundai Sonata from Car City in Michigan. In May 2025, the vehicle received a brand-new engine replacement due to previous problems. I picked the car up on [redacted], and on the same day, the vehicle began malfunctioning. It would not accelerate properly, jerked and stalled, and multiple warning lights - including the check engine light - came on immediately. This made the car unsafe to drive. I contacted the dealer, but they told me to wait until Monday to get it looked at, leaving me with a dangerous and unreliable car. The vehicle had already been in the shop for over two months for the engine issue, and I had only driven it for six months beforehand. I believe the repair or replacement engine is defective or was not properly installed. This creates a serious safety hazard. A car that stalls while driving puts everyone at risk. …
Check engine light start flickering while I was driving down the road my vehicle went into limp mode and I lost all power. I checked my oil for metallic shavings or a creamy look but everything was cleaned. I got a code 1326 for knock sensor. I replaced and changed the oil and oil filter and reset the code. I started it up and it sounded good then I drove to see if it was fixed got on the highway and my engine went back into limp mode I lost power again. And my engine started flickering I stop the car and tried to turn it back on but my engine locked up. Could I possibly get help with getting a new engine. The car only has 127,052 miles. I heard there was a bunch of problems with rod bearing wear and etc with 2017 Hyundai sonata se
I was driving southbound on I429 approaching the Vineland Wintergarden (FL)exit. approximately .75 miles from exit, a bit of an uphill. I heard a ticking noise, then suddenly the car went silent. The screen lit up with every sensor flashing. It took me a few seconds to realize I was in potentially deadly trouble. The car began slowing from 70 MPH to maybe 25MPH as I crested the last hill. To add complications, that stretch is under construction and does not have any shoulder. I could see a wall of cars streaming ever closer in my rear view mirror. I believe my hazzard lights probably saved me from a crash before gliding the last 1/4 mile to the exit where I was able to finally pull over to safety.
Important: This is hybrid vehicle. With the cruise control set to maintain a constant speed and while descending a long hill, the vehicle speed is maintained using dynamic braking by charging the battery. But if the grade is long - such as on CA 101 just north of San Luis Obispo, (locally referred to as the Questa Grade) there will come a time when the battery "gas gauge" reaches 100 % at which time the dynamic braking ceases and without warning the vehicle's speed gradually increases and can reach excess speeds. If you are not paying attention to the speedometer the speed can become excessive in a hurry.
While driving the engine light comes on and blinks rapidly and the car drops from the speed of 65 to 15 or below in second. The code was p1326 with is the knock senor. I changed it and the code went away. Weeks later the code returned while driving again with me and my 3 little babies in the car again. Same issue engine light came on blinking speed drop rapidly. Read this is an occurring issue with this car and it must be taken in to the dealer for fixing.Dealer refused to check out the issue.
Tl* May 3, 2019 2:34 p.m, contact was driving very slowly to make the turn into my assigned parking space, when all of a sudden, on its own, my car accelerated at great speed, forcefully pressing me against the seat back, flying over the stop curb at the front of my space, continuing across the gravel leeway before smashing part way through the cement block wall that surrounds our property. Demolished the front of my car as it punched a large hole in the cement block wall. Air bags deployed, causing deep bruising, swelling and abrasions on arms, legs and stomach. My left shoulder joint and upper back were wrenched enough that I am having to do physical therapy. Firemen and emt's were there and checked me out. The police were on site and filed a report. The dealer and the manufacturer were notified. …
Tl* the contact owns a 2017 Hyundai Sonata. While stationary on "auto-hold", the vehicle accelerated rapidly without warning at 40 MPH and crashed into a fence. After the contact released her foot from the accelerator pedal, the vehicle kept accelerating. In addition, the contact depressed the brake pedal to the floorboard in an attempt to stop the vehicle and the vehicle slowly came to a stop. The air bags did not deploy. A police report was not filed. There were no injuries sustained. The vehicle was towed to skyland collision in stanton island, new york. Island Hyundai in stanton island, new york was contacted about the crash and determined that there was a recall on the inhivorator switch of the vehicle. The vehicle was not repaired for the failure. The manufacturer was made aware of the issue and provided the contact with case number: 10776147. The failure mileage was 900.
Acceleration complaints in other Sonata years
Frequently asked questions
How common are acceleration problems on the 2017 Hyundai Sonata?
NHTSA has 20 complaints about the speed control & acceleration of the 2017 Hyundai Sonata, 3% of the model year's 766 complaints. The component named most often is cruise control (1 mentions).
Is there a recall for 2017 Hyundai Sonata acceleration problems?
No. NHTSA lists no speed control & acceleration recall for the 2017 Hyundai Sonata, though it has 3 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 2017 Hyundai Sonata acceleration problems start?
Half of the complaints with a recorded mileage happened before about 26,000 miles, and 46% before 25,000 miles.
Is it dangerous?
Owners linked 6 crashes, 1 fire and 2 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.