general problems of the 2015 Hyundai Sonata - part 1

While traveling on local roads and highways the vehicle transmission randomly down-shifts one or two gears. This has occurred when traveling in any gear from gears 3 through 6. It probably doesn't happen in 2nd gear because that is a transitory gear and not a cruising gear. After quickly moving the shifter from automatic mode into manual mode and then back into automatic mode the transmission returns to the proper gear. However sometimes it has down shifted again in as little as 30 to 60 seconds after resetting the shifter. This has been happening for years. The dealership has been unable to fix it. Because it is random, the issue is not readily reproducible by the repair shop. Sometimes it has happened several times within a 15 minute period. Sometimes it has occured multiple consecutive days. Other times a week or two has passed with no incident.

Our 2015 Sonata has experiencing engine failure several times due to excessive and irregular oil consumption. Our family’s safety and the safety of others on the roadway were put at risk as the engine slows, shudders and stalls without prior warning and the check engine light does not come on until the vehicle slows and stalls. The vehicle was inspected at a local Hyundai dealership, and they indicated that this is not covered under warranty. Summary of engine issues and failures: 1. May 3, 2022 – 68,671 miles (local Hyundai dealer) check engine light on, shudder; oil change performed. No cause identified. Paid out-of-pocket. 2. August 23, 2022 – 75,527 miles (retail shop) car engines failed on highway, towed to service shop. Valve cover gaskets replaced. Paid out-of-pocket in part and extended warranty paid part of the invoice. 3. April 29, 2024 – 109,229 miles (local Hyundai dealer) excessive oil consumption noted; valve cover gasket replaced again. Paid out-of-pocket. 4. January 22, 2025 – 118,341 miles (local Hyundai dealer) vehicle stalled en route to airport, towed to dealership; dealership advised oil change. Paid out-of-pocket. 5. May 20, 2025 – 122,000 miles (local Hyundai dealer) engine codes p0300, p0302, p0303 identified. Dealer diagnosed excessive oil consumption likely due to ring wear or sticking rings, contributing to spark plug misfires. Recommendation: engine replacement. Despite consistent and timely service, including multiple visits to the Hyundai dealership, the root issue has not been properly addressed. The current diagnosis of internal engine failure is a clear continuation of a pattern of unresolved engine problems (stalling in motion, oil leaks and oil consumption) all of which originated well within Hyundai’s original warranty. The vehicle has been well maintained, and all recalls have been addressed in a timely manner. Hyundai’s failure to acknowledge and take responsibility for this widely documented engine issue is a safety concern.

My transmission literally went out once on me the second day after I financed it. Now, less than a year later, it says I need to replace the transmission again. This is ridiculous.

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. . .

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.

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.

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.

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.

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.

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.

I purchased a used rebuilt 2015 Hyundai Sonata limited with only 39,000 miles on 9/1/23 for $11,000 cash. This is the money from my auto insurance claim from my previous vehicle that got totaled in an accident. The engine began having the very well known knocking problem the next day, 9/1/23. To explain, I was on a major road in my neighborhood known as ne 163 st/north miami beach blvd. That is when the engine check light began to flicker, I had to strategically & carefully drive the car across 2 lanes, traveling to the far right lane to exit traffic. The engine was hesitating, I could not get the car to speed up, to keep up with the flow of traffic, and exit this busy street as quickly & carefully as possible. I ended up pulling into the parking lot of a near by autozone. Being that they offer free diagnostic test, I got it done but, the car was not sending codes to explain the problem. I waited almost 8 hours for aaa roadside assistance to tow me & the car home. Then, I contacted jason erb, jose munoz who Hyundai America executives by email & phone. They assigned me to a executive communications national consumer affairs case worker who was not successful with getting Hyundai to resolve this well known problem with these cars. Being that my car is a rebuilt & not Hyundai certified, they refuse to replace the engine, as they do for qualifying Sonatas under 10 year/100000 mile factory warrantees. Plus, the dealer that I bought the car from wants an additional $1,900 to replace the engine. This is very unfair!! I feel that Hyundai should replace the engine, in good will, have grace/mercy , humility, & honor the fact that I have recently purchased & leased two brand new Hyundai vehicles. These defective engines pose a serious threat to unsuspecting drivers loosing engine power while on major busy roads!! what a dangerous situation to experience, out of now where, while driving in major traffic. Please help!!.

The contacts daughter owns a 2015 Hyundai Sonata. The contact stated that while the vehicle was idled 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 unexpectedly accelerated at rapid speed. The contact’s daughter was able to gain 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, and the diagnoses had not yet been determined. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 95,000.

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.

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.

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.

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.

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

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.

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.

I was driving on the freeway and all the sudden the check engine light started flashing. At the same time the engine slowed down and would not accelerate past 60 mph. I took the first freeway exit and drove to the nearest auto parts store. The store clerk hooked up a code reader and it came back with a p1326 code, power train system. Is it a real problem or just another bad sensor?.

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.

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.

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.

This is yet another incident of a Sonata hybrid hybrid flashing a warning to the driver and the the engine shutting down. This time it was Sep 7, 2022 in morristown, TN. . Read more...

2 recalls were found on my car and a service campaign. After taking my car to a couple auto shops, within 2 years my car has had the same repair issue involving p010 & p011 codes. After researching and finding there was a service campaign and 2 recalls, I decided to take my car to the dealership due to address the recalls. I took my car in on 8/1 and had a full inspection done on my car. Outside of the normal wear & tear, I was advised that the ecvvt cap was installed incorrectly, that it was leaking oil. I was told that cleaning the oil & reinstalling the cap would correct the problem, it didn’t and I’m out of additional money ($562) and the problem is reoccurring. I’ve called several times recently, as well as one of my mechanics, hadn’t received a return call not until I filed a bbb complaint. It seems they are not honoring or even considering the service campaign (ecvvt seating issue) and it is my belief, will continue to send me in circles to pay more money. A full inspection was done on my car, wasn’t nothing major but my engine light came back on in route home. I called the advisor and he couldn’t give me a definitive response as to when I could bring my car back & get it checked again. I wanted another appointment time so that I wouldn’t be inconvenienced by sitting at the dealership all day until they decided to check or get to my car again. It took me almost a month to get the 8/1/22 appointment. The staff I spoke with has tried to convince me that the issue with my car has nothing to do with the recalls or the ecvvt service campaign, I disagree especially experiencing the repeated p010 & p011 codes. One of the recalls also was for the ecm.

My abs lights came on and then minutes later my check engine light kept blinking while my car kept stalling or not let me accelerate in the middle of traffic. It’s like the engine dies but the car is on. It only stalls for a second then accelerates then stalls again and accelerates. Almost caused an accident. Seems that this is a problem for a lot of these models. It’s just crazy how it all happened back to back. My car has been running fine otherwise till that happened.

Multiple times, when the car start up and is put in to reverse, there is no throttle response. Simultaneously, it can not be put into the manual gear select mode and the car lurches into second gear.

The vehicle is slow to accelerate and as its accelerating it often will jerk or hesitate roughly. There have also been times when accelerating, such as getting on a highway, that the whole (what I assume to be) throttle system will almost stop and it feels like the car is just going to stop right there on the highway. It's very dangerous as cars behind me are also accelerating and not expecting my vehicle to just stop. The vehicle is available for inspection. There are no warning lights, messages, or symptoms prior to the issue. It has not been inspected by anyone yet.

Major oil consumption going on for years. Took in to dealer two years ago, they know there is a problem. They told me I could spend thousands of dollars to tear it apart to find out what is going on, and also told me to call corporate. I got no where with either, even though they recalled the engine in other Sonata cars, just not our eco model. Slowly started having throttle issues at 4 to 5 year mark. Informed dealer service center that it wasn't moving like it should when gas was pressed. Now, the car is having major problems with acceleration. Barely would go in reverse, drove 1. 5 blocks, speed not matching to throttle, press on gas, barely moving from a stop, going really slow, had to turn around and take back home. Our problem with the car is the same that others are complaining about. The car is not safe for a 7 year old car that started having problems at the 4 to 5 year mark.

Was driving with cruise control on and driving close to 70mph and the rpms shot up passed 5 then the car jerked and my speed had went from 70 down to 50 and 40 the cruise controle turned off on its own and the car lost power but was still on but it just wouldn't drive passed 2 rpms and the check engine light was flashing so I turned around and headed the opposite direction so I could get the car off the road then it made this loud noise sounded like throwing metal inside a metal bladed fan and then the car shut off and hasn't started since. The car did not over heat or have any smoke coming from it.

I was driving on the expressway. After about 18 miles the vehicle slowly decelerated to a stop. I was able to safely exit the expressway to the side street. I turned the car off for a few minutes. It started back up but has not accelerated pass 20/25 miles. There’s also major oil consumption. Camshaft position & ccv issues yearly requiring sensors to be replaced. Increased gas consumption. There’s also been a humming sound coming from the car that’s not been able to be diagnosed by any mechanics.

My car has been stalling, hesitating and sometimes I feel the engine shake when using the gas. I brought my car to the dealer to have the most recent recall fixed and asked them to diagnosed what else was going on with my car. They told me the stalling was just due to the recall. However, the very next day my car was acting up again. Additionally, the car at times will accelerate when I am not pressing on the gas. I don't think I need to go into detail about how my safety and the safety of others is compromised when you have a car that accelerates on its own. Lastly, there is no check engine light on. This has been ongoing for several weeks.

This is a follow-up to former complaint #11450586 (05-Feb-2022) and confirms that both my local Hyundai dealer -and- Hyundai corporation (USA) are aware of this diagnosable- and fixable problem—but they fail to issue a recall. In fact, a service advisor at my dealer expressly vocalized that 1) he himself [excluding his colleagues] has seen at least -2- of the same incident recently; and that 2) Hyundai corporation (USA) issued a “(service) bulletin” about the problem. Problem: the vehicle: 1) has a high idle; 2) shows a solid-illuminated cel/emissions light; 3) severely resists braking—my vehicle would even slide through stop signs; 4) fails to “pick up” normally; and 5) drives unsteadily. This is at minimum and is my experience from both last week and from the original report on 05-Feb-2022. As explained to me today (28-Mar-2022) by my service advisor, there is a known fault with a component within the engine (powertrain). Specifically, there is a tube that is—as I understand—meant to be free of fluids. However, and per the bulletin, the tube becomes full or over-filled with oil from the engine (powertrain). Further, the advisor suspects that changes in temperatures (e. G. , such as the teens *f back in Feb 2022) causes that oil/fluid to expand and contract, causing (further) damage. This issue must be remedied by Hyundai corporation (USA) immediately because it is a *safety risk. * my dealership emphasized severely how unsafe it would be to drive the vehicle off their premises without a repair. I’m fortunate because I’m the original owner and thus am covered by the 10 yr/100,000 mi powertrain warranty. Please save lives from these ‘flying’, uncontrollable cars by mandating a recall. **I will provide dealer’s documentation once vehicle is repaired. I was advised to wait 2-8 wks for parts and repair. **.

At low idle (stopping) car stalls out when stepping on gas. The rpms run extremely high and very low at idle causing panic. The vehicle also stalled at full speed on highway but all electrical was still working. Car tends to sputter and jump while shifting.

Car has been consuming an excessive amount of oil (1-2 quarts per week). While driving down the highway the oil pressure light came on and the engine started clicking and knocking. The engine died and all the dash lights came on. The car was coasted to the side of the road and towed into a local mechanic. The engine had seized and presumably dumped all the oil at the time of the engine failure since the engine had no oil when diagnostic was run. Car was taken to Hyundai dealership and is awaiting diagnostic and repair.