UNKNOWN, car was driving fine on the highway, then all RPMS were lost and the car couldn't accelerate past 40mph. At the same time a loud knocking started and when i was able to park and pop the hood, the engine was clearly vibrating and the source of the knocking is undetermined. there are recall's for improperly welded rods in the 2013/14 model sonatas and the 2016 so i find it hard to believe that Hyundai doesn't know that this year and make would have the same known issue and those models have all had recalls already except for mine...

- Midlothian, VA, USA

I have had my car serviced twice by the Hyundai dealership for the same exact issue. I believe I was told it was a knock sensor. A refurbished engine ended up being put in. The car is still having the same issues as when I first got it serviced in 2021/2022. My car is sputtering, loses power when accelerating and stalling. My car has always had an oil consumption issue and is causing additional issues with spark plugs.

- Mcfarland, WI, USA

While driving our vehicle (Hyundai 2015 Sonata Hybrid) around 25 MPH speed in city road... the vehicle stopped completely by itself in few seconds. Got the message "Hybrid System Warning! Safely Stop and Do not Drive" in dashboard and beep beep sounds. Thank god, no accident, the vehicles behand able to stop and avoid the collision. This is serious SAFETY issue, as this could cause accidents if vehicle stops by itself while driving. This is 3rd time in last few years with this vehicles. The recent incident happened was on 5/1/2024 morning around 8.00 am. We went to the Hyundai Service Center and they did looked at the codes and ran some scans and they found nothing wrong. And they said it could be some wrong system warning and can be ignored, as they can't reproduce the issue. And told us to report if this happens, but the worry is that, if this happens it could be serious life threating accident or injuries. They said they also got similar other Sonata Hybrid got same issue reported same day, but they can't find root cause. Same issue was happened last on 9/30/2022 and one before in that same year. They can't find the root cause that time too. They just updated software that time...and hoped that will fix. But the issue repeated again. While searching on the internet, found many people reporting this same error message and suddenly stopping the vehicle by itself. Very scary safety concern. So that's why we are reporting this to NHTSA. To take action on this with the Hyundai and investigate more. Now worried when we drive this vehicle. I have all pictures taken when this issues happened on 5/1/24 and also 9/30/22. I will share those here. Let me know if you need more information on this.

- Cumming, GA, USA

The car has been having problems with oil consumption. The problem became known in 2022, but the dealer/service department (Frank Hyundai, National City, CA 91950) did not care for the issue or safety. The dealer told me, "Your car is OK." On 7/3/2023, the engine light came on. A second round of oil consumption tests began along with a 90,000-mile service, including replacements of filter assy and gasket, four new tires and front and rear brakes, spark plugs, suspension/steering repair, shaft assy, engine repair, cooling system service, and fuel induction service. Shortly after, the car slows down even when my foot is on the accelerator. It feels like the vehicle will stall/stop (while driving in the middle of the road). I can see the rpm gauge erratically going up and down. The car lurches or jerks. I reported the jerky problem to the dealer at the second 1000-mi oil consumption test, but the dealer did not make any diagnostic tests or repairs because, per the dealer, "it did not jerk while we test-drove it." The problem continues.

- National City, CA, USA

The car has been having problems with oil consumption. The problem became known in 2022, but the dealer/service department (Frank Hyundai, National City, CA 91950) did not take care of the issue and did not care about safety. The dealer told me, "Your car is OK." On 7/3/2023, the engine light came on. A second round of oil consumption tests began along with a 90,000-mile service, including replacements of filter assy and gasket, four new tires and front and rear brakes, spark plugs, suspension/steering repair, shaft assy, engine repair, cooling system service, and fuel induction service. Shortly after, the car slows down even when my foot is on the accelerator. It feels as though the vehicle will stop. I can see the rpm gauge erratically going up and down. The car lurches or jerks. I reported the jerky problem to the dealer at the second 1000-mi oil consumption test, but the dealer did not make any diagnostic tests or repairs because, per the dealer, "it did not jerk while we test-drove it." The problem continues.

- National City, CA, USA

When I press on the brake the vehicle accelerate before it slows down. Sometime the car accelerates for no reason. This has been a recent problem for the past few months. The engine has been replaced from a prior recall.

- Naples, FL, USA

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.

- Davis , CA, USA

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.

- Henderson, NV, USA

Car stalls intermittently. When at a stop sign or red light, then when my turn to go I step on gas peddle, car starts to go, then stalls. I have to let off gas pedal and step on it again to get car going. This is dangerous as it leaves me in intersection and vulnerable to oncoming traffic. I had a mechanic check it out and they cleaned Throttle body, but that did not fix problem. No trouble codes showing up apparently.

- Crossville, TN, USA

Hybrid car with various hybrid system failures that results in sudden loss of power while driving. this has occurred 3 times to me while on the highway (I-75 in South FL). Car suddenly loses power, could not accelerate but I was able to get off the highway safety. This has been reproduced at the dealer and they first replaced the hybrid generator then the hybrid battery and ECM and now it occurred again yesterday while I had 2 children with me and now they blame the transmission. This is a dangerous car that should be recalled and investigated for the true cause of sudden and unpredictable power loss.

- Coral Springs, FL, USA

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. This should never happen! Once the car was towed to New Port Richey Hyundai in Florida, we were told that the car would be look after. The car was returned in the middle of July 2023 with a new electric motor installed. Everything was working fine until today, August 23, 2023. The same warning light that I brought the car in for in May 2023 is going off again. It only stays on for a second or two, so I don-??t have time to read it. I really hope this car does not shut off again with no brakes when traveling on the interstate. As mentioned before the car has low miles and is well cared for. This should not be happening.

- New Port Richey, FL, USA

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 failure mileage was approximately 95,000.

- Mineral Wells, TX, USA

The engine and yes it is. Because my car turned off in the middle of the loop on the highway when there was a lot of traffic and we could have gotten hit. No it has not been. No it has not been. We were driving on the highway then the engine started sputtering and it wouldn-??t go faster then 40 when I tried pulling off to the side that-??s when the engine, battery, and oil light turned on and after that the car just shut off and wouldn-??t want to turn back on.

- San Antonio, TX, USA

City driving and the bells and warning message on the dash stated the electrical system was being evaluated for causes why the engine/electric drive failed

- Powder Springs, GA, USA

can't use eco sport motor is accelerate and the car can't read the sensors a/c stop working brakes hard to press

- Providence , RI, USA

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. Although all these reports did not site any injury, major or death events, NHTSA should compel Hyundai to take appropriate actions to render the car safe to drive for the public because if accidents should happened, it cannot be undone and will affect lives of people. The public relies on a governing body to represent us and hold the manufacturer responsable to ensure that their mkt released products are safe: to save lives, prevent injuries, reduce vehicle-related crashes.

- Quebec, MA, USA

When I am driving car starts shaking a little I stop at a light and when I want to accelerate all of a sudden I step on gas and it wont drive i in middle of intersection it started shaking like it was going to turn off but didn't the check engine light came on but it never turned off i slowly accelerated and it kept driving I got to work turned it off when I turned back on the check engine light was no longer on.i have no idea what happened or why. And my brakes always make noise i had my breaks done in November they don't need replaced yet

- North Las Vegas, NV, USA

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. We called Hyundai and was told there was nothing they could do and we have to go the full thousand miles to determine if we qualify for the test. We are concerned are engine is going to stall, burn up or catch fire in our garage. They told us, we couldn-??t get are car in to be looked at until the end of March. After doing some research, I am aware that there is a current class action lawsuit against Hyundai for this issue.

- Ravenna, OH, USA

I have been keeping up with regular repairs and oil changes on my vehicle; so I was surprised when the oil light flashed once or twice in the past week, specifically when I took a turn tightly. The oil was low when I checked it so I added a quart and didn't think much of it except "I should get into a shop soon and have that checked out." Two days later, my RPMs red-lined past 6-7k and the car was revving up but was not accelerating at all. I pulled over and checked the engine again and without showing any kind of leaks (no spots in my driveway/parkingspot) the engine had consumed the oil I added and then some. Moreover, the problem with the engine revving up but not accelerating was not fixed when I added the oil. It could have been very dangerous if I were on the highway and was not able to accelerate for any reason that could put myself or my family at risk. Now, the car CAN reach speeds of 75+ miles per hour on the highway, but only after a LONG period of acceleration and seems to be burning oil VERY regularly. I've grown very concerned about catastrophic engine failure on the highway.

- Alexandria, IN, USA

When automatic headlights are on there are time that the headlamps will turn off when engaging the turn signals until turn signals are disengaged.

- San Diego, CA, USA