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'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 that while driving at an undisclosed speed, the car stalled and struggled to remain running. The contact stated two days later the vehicle was parked and while hitching the RV to the trailer hitch, the vehicle independently moved and collided with a dolly. The contact stated that the dolly was used to load the RV to the hitch. The vehicle was towed to the dealer. The vehicle was being repaired. The dealer informed the contact that the vehicle could not be diagnosed until the vehicle was repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 60,000.
The contact owns a 2015 Hyundai Sonata. The contact stated while driving 40 mph, the vehicle stalled with an abnormal knocking sound coming from the engine. There was oil leaking from vehicle. The check engine warning light was illuminated. The vehicle was taken to the local dealer and diagnosed that the CVT transmission seal needed to be replaced. The vehicle was repaired however, the failure recurred on July 20, 2021. The vehicle was taken to the same local dealer but was not diagnosed nor repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 30,000.
The contact owns a 2015 Hyundai Sonata. The contact stated while driving approximately 75 MPH, the vehicle began to vibrate violently. The contact pulled over and had the vehicle towed to a local dealer where it was diagnosed with needing a new transmission. The contact stated that the check engine warning light was illuminated. The manufacturer was not informed of the failure. The failure mileage was approximately 124,000.
The contact owns a 2015 Hyundai Sonata. The contact stated that while driving at various speeds, the vehicle would suddenly fail to accelerate above 25 MPH with the check engine warning light illuminated. The cause of the failure was not determined. The local dealer was informed of the failure, but no assistance was offered. The manufacturer was not notified of the failure. The failure mileage was 69,000.
Hybrid system warning comes up often and everytime I take it to get assessed, something different is getting fixed. These repairs are all expensive out of pocket repairs. The problems continues to happen and I'm constantly repairing something different.
While driving in city traffic, 45 mph zone, my car suddenly lost power, engine RPMs dropped, engine off, power steering impaired, I had to drift into turnout and assess. Car restarted, and I could drive, but RPMs would not exceed 1700, car wouldn't shift gears, speed would not exceed about 15 mph. No engine warning lights, no oil pressure indicator, no excess heat. I found I could drive at low rpms and manually shift gears to increase speed. I got the car to the local Hyundai dealer (Taylor hyundai, Augusta GA) and it has been there 8 weeks. They are telling me the engine has failed because I failed to change the oil for 14 months. They said my oil pan was empty. They asked me for maintenance records and said they were inadequate, and the engine needs to be replaced, may cost $6000 or more, warranty invalid. The car has 56,000 miles. …
In September 2022, we noticed a noise coming from under the car hood. Sounded like a thump as we accelerated. We took it to the Hyundai's service department and was told that they couldn't hear anything or find a problem. They changed my oil. We continued to hear a noise but thought it wasn't a concern. In February, a fairly new tire went flat and we returned to the Hyundai service department. I received a call later and was told that they could hear a noise and they checked, and my oil was extremely low. They topped it off and told me to return in a thousand miles to see if it was still burning oil. If it was burning significant oil at that point, they would seal it and begin the Hyundai oil consumption test. At about 600 miles, I could smell a strong plastic burning odor and we checked the dip stick and the oil was barely detectable. …
2015 Hybrid Sonata, milages at 82,000 km, owned for 8 years. "Hybrid system warning, do not drive" message occurred, car lost 100% of its power, went into complete stop without any warnings on the middle of the highway. Hazard lights do not work and unable to warn incoming traffic that the car has completely stalled in the highway. The car is unsafe to drive. Went to Hyundai (here in Canada) several times, being charged every time for diagnostic and repair works, been told that the issues were fixed via software update. Problem persists. There are compelling evidences from different car forums, websites and NHTSA own database (28 reports under Unknown, 22 reports under Electrical sys. categories...) on the hybrid system failure or/and 100% power lost lead to complete stalled car. …
I would like to write about my experience with New Port Richey Hyundai. I have owned a Hyundai Sonata Hybrid Limited since 2015. I take immaculate care of my car and it only has 65,000 miles. All maintenance has been done regularly and on time. For the last six months I have had a warning light and alarm going off for a few seconds once in a while, which shuts off my cruise control. I took the car in, in the spring of 2023 to have the codes read and no problems were found. Finally, In July of 2023, while my wife was in traffic it started again and totally shut off the car. Unfortunately, the brakes did not work as well. She was going up a slight incline and was able to come to a stop. The brake pedal went completely to the floor. The warning was about a Hybrid System Failure. It was very upsetting to her that her brakes failed when the Hybrid system had a problem. …
Related recalls
Power train › Axle assembly › Axle shaft
Hyundai Motor America (Hyundai) is recalling certain 1.6 liter model year 2015 Sonata vehicles manufactured August 29, 2014, to October 28, 2014. The affected vehicles may have been assembled with an incorrect left axle shaft which may result in the shaft separating from the transaxle differential.
Remedy: Hyundai will notify owners, dealers will inspect and replace the axle shaft, as necessary, free of charge. Owners may contact Hyundai customer service at 1-800-633-5151. Hyundai's number for this recall is 126.
Transmission complaints in other Sonata years
Frequently asked questions
How common are transmission problems on the 2015 Hyundai Sonata?
NHTSA has 135 complaints about the transmission & drivetrain of the 2015 Hyundai Sonata, 12% of the model year's 1,153 complaints.
Is there a recall for 2015 Hyundai Sonata transmission problems?
Yes — NHTSA recall 14V-784 (axle shaft, Dec 9, 2014). Recall repairs are free at authorized dealers.
At what mileage do 2015 Hyundai Sonata transmission 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 1 crash, 0 fires and 2 injuries to transmission & drivetrain 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.