2015 Hyundai Sonata Speed Control & Cruise Problems

My 2015 Hyundai Sonata has demonstrated multiple instances of unintended acceleration and braking failure: April 20, 2024 – While idling in a drive-thru line, the vehicle suddenly lurched forward without any attempt to accelerate and crashed into the vehicle in front of me. I was unable to stop it. This resulted in the other car being totaled. I took it to a Hyundai dealership afterward, but they found no definitive cause. April 4, 2025 – My daughter was driving and attempted to stop at a red light. Despite applying the brakes, the car did not stop and continued through the intersection, striking the door of another vehicle. May 12, 2025 – Today, while using cruise control set to 55 mph, the car began accelerating beyond the set speed without input. It appears the cruise control system is malfunctioning and not disengaging as expected. The vehicle currently shows no open recalls, but I found that similar issues were previously investigated under NHTSA action DP21003 for this model year. These incidents occurred months apart, but the behavior is consistent and extremely dangerous. I am requesting a formal investigation. The safety of my family and others on the road is at risk.

The contact owns a 2015 Hyundai Sonata. The contact stated while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. In addition, the check engine warning light illuminated, and the vehicle lost motive power. The vehicle was towed to the dealer where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure; however, the engine replacement request was denied. The failure mileage was approximately 140,829.

Engine just stopped working. car stop running turned off in the middle of traffic in Dallas Tx. I took my car for an oil change the mechanic said he’s had plenty of 2015 sonata engines just give out and some catch a fire as well.It gave no warning and no smoke. This happened last week.

I am 86 years old. I bought the car brand new so I am the original owner. I have kept the car perfectly maintained and garaged from the day I bought it. My wife is also 86. She and I are the only ones that drive the car. To date, it has 73,822 miles on it. The main issue I am having is random, unpredictable stalling and hesitation when trying to accelerate. We have also had unintended acceleration. This always happens at the worst times which causes grave concern for our safety. We have taken the care to the dealership here in Cape Girardeau, MO called Chris Auffenberg Hyundai. They've charged me $130 only to tell me nothing is wrong. I have continued to try to work with them and they now have decided a new fuel pump will fix this which is $730. I have noticed there are already hundreds of complaints on the 2015 that all say they have the same exact issues I am having but this dealership doesn't seem to care. Here is what I have read. "The most common issue in the 2015 Sonata lies with its faulty throttle control system, which can cause stalling, hesitation, and even unintended acceleration. Currently, there is no fix from Hyundai." My dealership will not acknowledge this even though it is public information. I feel like they are going to keep replacing parts and are taking advantage of me. [XXX] is the Service Manager at this dealership and I am not happy how he is handling this. Please let me know if there is any additional information I can provide. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2015 Hyundai Sonata. The contact stated while driving approximately 3 mph and entering a driveway, the vehicle accelerated independently and crashed into a metal gate. The contact stated no warning light was illuminated. The contact stated no air bags were deployed. The contact stated no one was injured nor sought medical attention. The contact did not contact the police department nor filed a police report. The vehicle was not drivable and was left at the locations of the incident. The vehicle was not diagnosed or repaired. A dealer was not contacted. The manufacturer had not been informed of the failure. The failure mileage was approximately 63.000.

My daughter was driving on the interstate when the car went into limp mode and the engine light was flashing. We had it towed to hyundia dealership where they did an engine update. Had it for 3 months when it did the same thing to her again. Had it towed again to same dealership where they are telling me it needs a new engine.

The engine stalls out randomly. This is the third time it's done it. The first time was while I was exiting the freeway on March of 2021, which I thought was a fluke. The second time was July 19th and the third time was July 30th. There were NO warning lights or messages. Took it to the dealer and they said that everything came back fine with the engine. They confirmed that the RPMs were too high when it was in a parked position and the engine was on when they first took it in. They suggested I replace the starter. I'm going to a different mechanic for a second opinion. The car was in motion with my foot on the gas pedal when it started to stall. There is no way that it is from a starter.

The contact owns a 2015 Hyundai Sonata. The contact stated that while driving 40 MPH, the vehicle failed to accelerate while the check engine warning light was illuminated. The vehicle was towed to an independent mechanic where it was diagnosed that the throttle control module needed to be replaced. The vehicle was repaired however, two weeks later the check engine warning light illuminated. The vehicle was taken to the dealer where it was diagnosed that the Voice Coil Motor (VCM) needed to be replaced. The vehicle was repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 127,828.

My engine light has been on for over one year. I took it to the dealership to see what was going on and to get an oil change. The dealership stated that there could be a variety of issues and that they would turn the light off and when it came back on to bring it back to them. The staff was not the most professional so I opted to not take it back unless there was a significant issue. My car constantly accelerates when I am on the brakes at a light and then when I let off the brakes, the car accelerates before I put my foot on the gas. I recently backed out of my parking space and without my foot on the gas, I bumped into a neighbor's car. There was no damage to their car but my car has a dent in it. Everyone is safe and fine but this could have been way worse if I was in a parking lot or on the road. The car does not accelerate when I put my foot on the gas on the highway either. I have had some close calls getting onto the highway because I can press the pedal to the floor and not get the speed needed to go fast enough. I am making plans to take it back to the dealership and report my dent because this acceleration issue is very annoying when driving and I know that it is dangerous in situations where I should be able to shift the gear and not be moving fast enough to get a dent. I hope Hyundai really looks at this issue and helps us out. Thank you.

I HAVE BEEN RECEIVING A 'SAFETY STOP. CHECK HYBRID SYSTEM' WARNING MULTIPLE TIMES. I HAVE TAKEN IT TO HYUNDAI MULTIPLE TIMES TELLING THEM OF THE ISSUE. THEY KEPT TELLING ME NO ISSUE COULD BE FOUND. THE LAST INSTANCE THEY UPDATED THE SOFTWARE IN THE CAR IN WHAT APPEARS TO BE A HAIL MARY TO SAY THEY DID SOMETHING. LAST NIGHT I WAS TRAVELING I WAS TRAVELING ON THE HIGHWAY AT ABOUT 60 MPH. THE CAR STARTED DINGING AND GAVE ME THE WARNING ERROR ATTACHED. THE CAR COMPLETELY LOST POWER AND ONLY ALLOWED ME TO COAST. I WAS LUCKY ENOUGH TO BARELY ABLE TO GET MYSELF INTO A LOCATION OF RELATIVE SAFETY. I PARKED THE CAR AND RESTARTED IT AND WAS ABLE TO DRIVE ONCE AGAIN. THIS CONTINUES TO BE AN ISSUE, EXTREMELY UNSAFE, AND HYUNDAI CANNOT GIVE ME AN EXPLANATION OR FIX THE PROBLEM. THIS IS UNACCEPTABLE AND ALMOST LEAD TO A MASSIVE ACCIDENT.

I'm really at wit's end with what is going on with my car. My car is currently at 104K, its a 2015 Hyundai Sonata Sport. A beautiful car with an abundance of serious issues. I've had trouble with my car accelerating for over a month and I've taken it to at least 5 mechanics who have troubled shooted with no success to fixing the issue. The problem: my car hesitates significantly when accelerating and sometimes when it's can't shift gears and I'm easing my foot on and off the gas pedal, it begins to shake while attempting to accelerate. I try not to put the car in sport mode but sometimes this mode is what helps the car shift gears but I don't think this good for the car. So far I've tried changing all of my spark plugs and coils replaced, fuel injectors cleaned (dealership), transmission fluid changed and ECM updated (dealership). Also, the Hyundai dealership diagnosed the issues as an engine problem (intake exhaust and timing chain + tensioner) --- cost of all these things almost $4000!! I just don't understand why the check engine light is not coming on -- which is hinting at the local mechanics that it might be a transmission based issue. No the check engine light has not come on but the car drives really poorly. I'm taking it to a transmission shop and hopefully going to get some answers as to what is going on. This issue is absolutely frustrating and now I'm just looking for real direction by waiting to see if the engine light will come one and throw a code

The contact owns a 2015 Hyundai Sonata. The contact stated that while operating the vehicle, it would not immediately accelerate when pressing the accelerator pedal. The check engine light would remain illuminated. Also, the vehicle had experienced unintended acceleration. The vehicle was taken to an independent mechanic who reprogrammed the engine software but the failure continued to occur. The local dealer was notified of the failures. The manufacturer was not yet contacted. The failure mileage was 50,000.

told the Hyundai dealer 2 years(March 2021) ago that I was concerned about my oil light flashing periodically between scheduled oil changes. No action other than oil changes and one time they added a couple of quarts "no charge" as it again was low. Continued to change oil more often than necessary and the frequency increased. Multiple other car repairs have been happening and the oil now has to be added weekly to maintain proper amounts. Had to change spark plugs 2 times with in 5 months and now another engine light came on today 11/15, and when I check the code at a parts store I was told is was a P03001 and P03002 which was something to do again with the cylinders misfiring. Everyone I have spoke to says this is an engine issue and it is under recall. I did place a claim with Hyundai Care USA after being told by the dealer that it would be better if I did this instead of them. The assistant manager also confirmed that the engine is covered 100%. I did this in September after the second repairs. The Regional Manager finally called me back and indicated he agreed about the problem needing to be resolved and would call me after he spoke to the dealer in a day or two. It has been over a week and no one has called. I keep leaving messages. I now have the same error codes, it is November 15 and the spark plugs were all changed less than 2 months ago for the exact same reason. I have been stranded and at times when I accelerate onto traffic the car will not respond. I do not use the interstate anymore as I cannot predict when the car will slow down and not get enough speed and cause an accident. I only drive to work and back right now. I was given this website by the employee at the parts store along with some information concerning P1326 codes and they are engine related. I will upload the most recent repair receipt.

VEHICLE STARTED SLOWLY CRANKING FOR A WEEK OR SO AND THEN WHILE DRIVING IN A 55MPH ZONE, SPEED SUDDENLY DROPPED TO 20 MPH WITH CHOKING TO THE POINT OF PULLING TO A SAFE AREA AND HAVING CAR TOWED 11-4-2020

WHEN TRYING TO SET MY CRUISE CONTROL A MESSAGE POPS UP ON MY DASH SAYING SCC CONDITIONS NOT MET.

I was driving to work as I normally would from the University I attend. About half way to my destination the check engine light illuminated and right when I was about to find a safe place to stop the car abruptly stopped in the middle of the Highway and stalled on one of the most dangerous highways in the U.S. being US I-20. I almost immediately got hit from behind however a few vehicles behind me did get involved into an accident due to the my car stopping abruptly with little warning. I called hyundai immediately and asked for a tow driver however the wait time was excessive and I had to go to work. I was able to start the car after 20 minutes, but it was in limp mode and I pulled off to the side of the road and had to uber to work. The next day I had got a tow truck to pick up my car and take it to the dealership where they said the car had accidentally triggered the knock sensor by mistake and replaced it free of charge. However the very next day it happened again after driving about 30 miles. And I took it back to the dealer they offered the same thing a replacement sensor. When I did some research and the car actually needed a new Engine after a recall had been placed. Hyundai refused to replace the engine after the knock sensor deployed. This is Hyundai's issue and it needs to be addressed. I was forced to put the car on the side of my house for the time being and get a rental until I could afford another vehicle. This is very disappointing from a consumers point of view. I filed with the extended warranty campaign TXXC and got denied due to the amount of miles on the vehicle. However there was no warning before the engine failed. The car was very well maintained and had regular Oil changes with full synthetic oil every 5k miles. No precursors to the engine failing occurred, like a knocking or jerking or anything. This is an issue that hyundai need to address. I am very disappointed. Campaign reference number for my case 17507525.

DRIVING HOME AND ALL OF A SUDDEN THIS ALERT GOES OFF. BRAKE SYSTEM WARNING, PULL OVER NOW. CHECK BRAKES. CAR SLOLWS SHUTS OFF AND I'M STUCK ON THE ROAD. HAD TO GET A TOW AND NOW CAR WON'T START. SHOWS SAME WARNING WHEN I TRY TO START IT.

TL* THE CONTACT OWNS A 2015 HYUNDAI SONATA. WHILE DRIVING VARIOUS SPEEDS, THE BRAKE PEDAL WAS APPLIED, BUT THE VEHICLE FAILED TO RESPOND AND CONTINUED TO MOVE AND IDLE. THERE WERE NO WARNING INDICATORS ILLUMINATED. THE VEHICLE WAS TOWED TO AN INDEPENDENT MECHANIC WHO STATED THAT THE BRAKE SENSORS AND THROTTLE BODY NEEDED TO BE REPLACED. THE VEHICLE WAS REPAIRED. THE LOCAL DEALER WAS NOT CONTACTED. THE MANUFACTURER WAS CONTACTED AND PROVIDED CASE NUMBER: 16052684. THE CONTACT REQUESTED REIMBURSEMENT, BUT WAS DENIED. THE FAILURE MILEAGE WAS 35,137.

SCC REFUSES TO COME ON SAYING SCC CONDITIONS NOT MET. WHEN IT DOES COME ON IT TURNS OFF BY ITSELF SAYING SCC CONDITIONS NOT MET OR CHECK SCC RADAR. SOMETIMES DOES NOT DETECT VEHICLE IN FRONT OF ME. GOES IN AND OUT BETWEEN DETECTING VEHICLE IN FRONT OF ME AND NOT DETECTING IT. RANDOMLY SAYS CHECK SCC RADAR. DOES NOT STAY ENGAGE, TURNS OFF BY ITSELF, WILL NOT TURN BACK ON. THE CAR WAS IN MOTION ON A HIGHWAY.

AROUND 25000 MILES, AFTER START, STRONG ENGINE VIBRATION WITH NO POWER - ABOUT TO STALL. DEALER CHANGED VARIABLE CHARGE MOTOR AFTER 5 OCCURRENCE OF SIMILAR SITUATION. AFTER FEW MONTHS AT 29000 MILES, 2015 SONATA SE (2.4L 4 CYLINDER ENGINE) LOST POWER AND STALLED IN THE MIDDLE OF CITY STREET, WHILE DRIVING. COULD HAVE CAUSED BIG ACCIDENT IF I WAS ON HIGHWAY. CAR WAS UNABLE TO RESTART. TOWED TO DEALER AND REPLACED ACCELERATOR POSITION SENSOR. COULD BE RELATED TO ISSUE WITH 2011-2014 SONATA ENGINE RECALL SINCE MY 2015 SONATA USES ALMOST SAME THETA-II ENGINE.