The contact owns a 2014 Hyundai Sonata Hybrid. The contact stated while driving onto an on-ramp at an unknown speed, an abnormal knocking noise was heard. The vehicle was able to accelerate to approximately 40 MPH. The contact stated there was no warning light illuminated. The vehicle was driven home and then to a dealer. While at the dealer, the failure was diagnosed as a piston failure. The contact referenced NHTSA Campaign Number: 20V746000 (Engine), and the VIN was included in the recall. The contact stated that the vehicle was not repaired under the recall. The contact stated that the dealer provided the test results to the manufacturer. The contact stated that the recall repairs were denied by the manufacturer due to negligent maintenance. The contact stated that he had owned the vehicle for 3-weeks. The manufacturer was not notified of the failure. The approximate failure mileage was 116,000.

- Saint Marys, GA, USA

I was driving 20 mph straight down a flat residental street. A loud dash alarm sounded in my 2014 Hyundai sonada hybrid. The dash displayed "hybrid system warning, safely stop and do not drive". below the warning a yellow caution triangle displayed. I attempted to give the vehicle gas, so I could pull to the side of the road, but the engine acted like it had no power. A blinking green "ready" light was displayed. The eco guide display was moving up and down from the top to bottom. I took my foot off the gas pedal and began braking. The brakes felt mushy and the vehicle was not stopping. Within a few seconds the vehicle shook and was the engine was revving up and down but like it was out of gear. After approximately 10-15 seconds, I lost the power steering and the it was almost impossible to turn the steering wheel. I again tried braking but the brakes just felt mushy and were not stopping the vehicle. I continued coasting down the road and eventually used the emergency brake to stop the vehicle. Once the vehicle was stopped I shut it off and attempted to started the vehicle again. The green "ready" light displayed on the dash as well as the warning lights. The vehicle would turn on but not start again. I put the vehicle in neutral and had several people push me to the curbside. The brakes were very mushy and almost non-existent. I again used the emergency brake to stop it. I notified my local Hyundai dealer and advised I would be towing the vehicle to them. I had just came off the freeway and had this happened a few minutes earlier, I would not have been able to get to the shoulder of the freeway. I believe this issue could have caused serious injury or death. It was literally terrifying to lose control of the vehicle the way this occurred. There was no prior warning of an issue and not enough time to react once the warning symbol was displayed.

- Corona, CA, USA

While in motion going 60mph, vehicle sputtered and then an alarm sounded along with a warning displayed on the drivers side screen stating "hybrid safety warning. Pull over and do not drive." The car would no longer accelerate and came to a stop. Had to restart the car. The same warning happened again the following day while in motion going 50mph. Had to get out of the roadway and restart the car. Hyundai replaced the entire engine under manufacturer warranty (took about 5 months). Upon receiving vehicle back, the same issue happened in the first 10 mins of driving it (issue not fixed). It is back at the Hyundai service center awaiting repair.

- Wellington, FL, USA

2 times the engine stalled in the middle of an intersection due to hybrid system failure. A simple fuse for the hybrid system went out and turned off all power. The main issue is that this is a very dangerous design flaw. Other hybrid vehicles have a safety feature that when the hybrid system is not working the gasoline engine will still be in full operation. Everytime the engine light goes on it kills the whole car. I got stuck on an expressway and was put in a dangerous situation when this did not have to happen because they don't have to make the 2 motors completely dependent on each other. Having the gasoline engine continue to run and be able to power the car in a hybrid system failure will save someone's life. I am not sure why this is not a requirement by law to have this safety feature

- Sunrise, FL, USA

While driving car system warning came on to" safely stop and do not drive". was able to pull over and stop car. Could not restart it. Had it towed then changed battery which was low. Tried to restart and did not turn on until 3rd time starting. Let engine run for about 10 min and warning came back on.

- West Sacramento, CA, USA

I bought my used car September 1 it's a 2014 Hyundai Sonata hybrid, with a little over 61000 miles on it, I had to evacuate from a hurricane about week after that, when I returned I checked the oil on my car there was no oil showing on the stick the oil light never came on, I took it to the dealership they said engine oil drain bolt washer had crack in it, they put oil in and said everything was fine. I had to go out of town this past week and on the way back I checked the oil it was about a quart and a half low I called the dealership and ask the service manager what type of oil they used was it synthetic or regular oil she went and ask the mechanic she came back and said do not put oil in it because it would void the warranty I ask her how that would void it, she didn't have an answer for me and I got kinda mad cause they would not tell me what oil to put in it, then I drove to the next rest area a checked it again there was no oil on the stick I tried to call the dealership they would never answer the phone I guess they had caller id, so I called a tow truck and took it to the closet Hyundai dealership they put it on the rack the under belly was clean there had been no leak, he then took off the oil cap and there was so much sludge build up he said the engine was torched no way it could be fix, I ask way the oil light never came on, he said because of all the sludge in there, he said this should have never been sold

- Brunswick, GA, USA

The contact owns a 2014 Hyundai Sonata hybrid. While attempting to start the vehicle, the engine failed to start although the lights and radio were activated. The vehicle rolled when placed in gear. The vehicle was taken to Hyundai of columbia (1370 nashville hwy, columbia, tn 38401). The dealer could not diagnose a failure and recommended that the battery be changed. The battery was changed, but the failure recurred. The manufacturer was not made aware of the failure. The approximate failure mileage was 36,000.

- Columbia, TN, USA

El carro tryna cuando voy de reversa Y cuando estoy an stop el carro tiembla Y los brakes ya SE los cambie Y siempre me hace ruido..

- Las Vegas, NV, USA

Hybrid system warning has come on four times, car shuts off instantly, then the engine light comes on. The first time was on a city street, the second time was a the dealership when picking up the car after repair, the three time was in a parking lot, and the fourth time was on the interstate in heavy traffic. Car is not safe. Asked for a replacement with no resolution.

- Munfordville, KY, USA

My 2014 Hyundai Sonata hybrid starts off very slowly when pulling into traffic and then launches forward once the gas motor starts. My concern is that I'm going to get rear ended when pulling into traffic because of the slow start or I'll lose control as it launches forward. Either way, I don't feel safe. The Hyundai dealership that I purchased it from said that it's "normal" and that "all hybrids perform that way". I know for a fact that this is not true. I've contacted the dealership, but they refuse to help and continue to ignore my complaints. This vehicle, I believe, is unsafe for me, my family, and for other drivers on the road. I wouldn't drive it, but I have no other car and I need to get to work.

- Norwalk, CA, USA

After just two months of ownership, this Sonata hybrid wouldn't start (for the second time). Had it towed to the dealership. After 15 days (total so far for both incidents) the dealership still has no idea what's wrong with it or how to fix it. It seems to be something related to the electrical system.

- Union City, NJ, USA