2015 Hyundai Sonata Problems

After receiving the Hyundai Service Campaign 9C2 update on my 2015 Hyundai Sonata on XXX, I have started having jerky acceleration when the car is first started and am driving. Also, while driving at highway speed (~65 mph)) and I take my foot off the accelerator to coast, the engine RPM drops suddenly, anywhere from 250 rpm to 750 rpm, then recovers abruptly to where it was at prior to the drop (typically around 2000 rpm). The engine rpm also drops while driving at slower speeds and recovers but is not as noticeable as it is at highway speeds. It was not doing this prior to the Service Campaign. There are no check engine lights or pending codes. I brought it back to the Hyundai dealer and discussed the issue with them on XXX. They acknowledged it was likely due to the Service Campaign and they did not want to keep the car to look at it and said no damage was being done and it was safe to drive. They said a fix was in the works but did not know how long until it was released and I should receive information in the mail on it. Video link [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

In March 2026 Hyundai did an emissions update Campaign 9C2. Since that update my 2015 Hyundai Sonata SE has run rough and shifted hard. Hyundai stopped doing the update in May 2026. Hyundai has not provided any update to fix the problem they created. I am worried the update is damaging the motor and transmission of a car that was running just fine prior to the update.

1.) Following Hyundai's 9C2 Campaign update for the ECU that was completed back on May 27th, 2026, my 2015 Sonata went into limp mode [solid check engine light present] while I was accelerating up an on-ramp on the 2nd drive cycle since the update was performed. I was already far away from the dealership so I was forced to limp it to my local shop that I regularly use to have it checked out. It was confirmed that the code on the vehicle was P200A for intake manifold runners. Since the update was for smog regulation, the code was cleared in order to see if it would come back. Since then, it has not, however the vehicle continues to have one persistent problem. The RPMs will dramatically dip and then surge back upwards while the car is coasting (no gas and no brake applied). 70% of the time, you can feel the car violently jerk as it appears to try and correct itself. 2.) I've brought this car to multiple dealerships, have a case open with corporate and have also found that this is a systemic issue with this specific update in these cars. All and all, nothing has been done. I'm repeatedly turned away over and over again because their techs are only permitted to look into it once they have hard evidence of a fault. In this case, that would be a dashboard light. I'm told that I may only return if the check engine light comes back, which as I mentioned previously, posed a HUGE safety risk to myself the first time it appeared. If I can only go 55mph down the highway, I am at risk of being rear-ended or struck in some way. 3.) The problem has not been reproduced by the dealer as they will not test drive it to see the dip and spike. However, the code was still pending for awhile in the vehicle before it cleared it on its own, so that was acknowledged by at least one place. 4.) Vehicle has not been inspected by anyone but a dealership and local mechanic. 5.) No other signs prior to the vehicle limping out on me other than some acceleration concerns on May 27th, 2026.

This vehicle had a recall, 201, for the smart junction box. This was due to the blinkers not working properly. The software update was performed, however, the problem still exists. This was due to the smart junction box. Now, aside from the blinker issue, the ac stays on when the engine is turned off, lights come on by themselves, the media screen goes randomly into night mode, daylight running lights are constantly in night mode, smart junction box failure. I have not taken this to a mechanic as of yet, the dealership is aware, and I opened a case with Hyundai case #42940056, however, I have not received a call from my service advisor or Hyundai. They offered to do diagnostics, but, if these problems are not about the safety recall, I would have to pay $350 for diagnostics, unless I get the problem fixed by them. This car has 66k miles with a new engine installed at 59400 miles! At this point, I have the car parked, battery disconnected, and looking for the most efficient way to fix the problem, which must be performed by specialized equipment.

In March 2026 Hyundai did an emissions update Campaign 9C2. Since that update my 2015 Hyundai Sonata SE has run rough and shifted hard. Hyundai stopped doing the update in May 2026. Hyundai has not provided any update to fix the problem they created. I am worried the update is damaging the motor and transmission of a car that was running just fine prior to the update.

VEHICLE: 2015 Hyundai Sonata, 2.4L Theta II GDI engine Mileage at time of incident: [ 93k Date update performed: June 2026 Dealer/location where update was performed: Fitzgerald Hyundai Gaithersburg, MD DESCRIPTION OF PROBLEM: After my vehicle received the ECM software update issued under Hyundai Service Campaign 9C2 (ECU Software Update for Theta II Emissions Improvement, TSB 25-01-087H / 26-01-013H-1), the vehicle began exhibiting noticeable jerking/hesitation during acceleration that was not present before. For this vehicle this happens consistently after a cold start then does not happen again.

My 2015 Hyundai Sonata has a defective engine. The motor failed unexpectedly even though the car has low usage and has always been maintained properly. I was informed that many Hyundai engines from these years came with manufacturing issues, and mine appears to be one of them.

The engine light started to come on and go off and when I got the codes ran, it said something along the line of misfire. I had the spark plugs changed and I kept regular maintenance done on oil changes and tune ups. Now my engine is knocking and the vehicle is in limp mode.

After receiving the Hyundai Service Campaign 9C2 update on my 2015 Hyundai Sonata on XXX, I have started having jerky acceleration when the car is first started and am driving. Also, while driving at highway speed (~65 mph)) and I take my foot off the accelerator to coast, the engine RPM drops suddenly, anywhere from 250 rpm to 750 rpm, then recovers abruptly to where it was at prior to the drop (typically around 2000 rpm). The engine rpm also drops while driving at slower speeds and recovers but is not as noticeable as it is at highway speeds. It was not doing this prior to the Service Campaign. There are no check engine lights or pending codes. I brought it back to the Hyundai dealer and discussed the issue with them on XXX. They acknowledged it was likely due to the Service Campaign and they did not want to keep the car to look at it and said no damage was being done and it was safe to drive. They said a fix was in the works but did not know how long until it was released and I should receive information in the mail on it. Video link [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Issue- fuel pump/supply line causing fuel to leak and fuel smell around the outside of the car. This can cause a major fire, explosion, death for myself and others around me. Problem has been confirmed by auto repair shop. No warning messages on car dash board, just strong smell of gas. Replaced gas cap and smell is still there.

Brake lights not working properly.

I have the 2015 Hyundai sonata with the 2.5 GDI engine that eventually will seize due to internal damaged caused by manufacture design flaws. My Hyundai threw a P0010 code which causes my car to idle high and causing low vacuum affecting my brakes. I had a diagnostic test done at a Hyundai dealership that told me it was a cvvt cam sprocket issue and that it was the beginning of the end of the engine, They quoted me 3700.00 but the engine was to far gone and this repair would only accelerate the engine to seize. They said since the engine isn't seize Hyundai will not cover the cost to repair or exchange the engine, I contacted the Hyundai customer service who stated since the repair that is needed wasn't the root cause of the problems associated with the engine swap warranty they were not going to help me even though I explained to them that the cars high accelerating and the braking system been jeopardized and been told the engine is beyond repairs I feel Hyundai should reconsider their decision and help a loyal customer. I have purchased 12 Brand New Hyundaj since 2001. The customer Representative was Extremely un Professional even suggesting I scrap my car, Also I contacted My Hyundai service Technician who said Hyundai customer service never contacted them about my car, When they said they spoke with the technician. Also I received an Extended warranty on the 2.4 GDI engine from Hyundai who many Hyundai customers are or have dealt with.I also purchased an Extended warranty Which I believe should have been extended as well Thank You

The contact owns a 2015 Hyundai Sonata. The contact stated that while driving at lower speeds, the steering wheel became difficult to steer in either the left or right direction. The Traction Control, Power Steering, and the high-beam warning lights were illuminated. The vehicle was taken to a local independent service center, where it was diagnosed with error codes: C167286, C126008, C136008, C126002, and C168808. The vehicle was not repaired. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 195,000.

The steering column locks up. When start vehicle and make turn to get on road the steering locks up and cannot turn the wheel. This is safety concern and not safe to drive.

I was driving my 2015 Hyundai Sonata approximately 35 mph after leaving the Hyundai dealership following an engine replacement when the hood unexpectedly flew completely open without warning. The hood struck the windshield, completely obstructing my forward visibility and creating an extremely dangerous situation. I was able to safely pull over without causing a collision, but the vehicle sustained extensive damage and was declared a total loss by my insurance company. During the same service visit in which the engine was replaced, the dealership recommended replacing the hood latches, but I declined that repair. Hyundai later informed me that the hood latching system was functioning properly after the engine replacement and that the vehicle passed its post-repair inspection and road test. Approximately one mile after leaving the dealership following the engine replacement, the hood unexpectedly opened while I was driving. There were no hood-ajar warnings, warning lights, or other indications that the hood was not properly secured before the incident. The sudden loss of visibility created a serious risk of a crash that could have resulted in severe injury or death. I am submitting this complaint because I believe this incident represents a significant vehicle safety issue that should be investigated.

The vehicle’s sunroof just flew off the car at 31 miles per hour (the whole part), Hyundai had a safety recall for that and it was done in the past, the problem is that happened exactly what the recall were suppose to prevent, it was my wife and 2 kids on my car and I’m glad it was before she enter the highway, it would cause a major wreck with multiple vehicles. The car behind her had a dash cam and recorded the event, I’ll upload for better understanding. I’m also posting it on the social media to get publicity on the event.

The rubber stopper for the brake light switch on the brake pedal deteriorated and fell apart. This resulted in the brake lights remaining on constantly, cruise control being disabled, and low battery voltage.

My lights come on when the car is parked and the engine is off,mostly during the night its happened twice in 2months.

I was driving my 2015 Hyundai Sonata approximately 35 mph after leaving the Hyundai dealership following an engine replacement when the hood unexpectedly flew completely open without warning. The hood struck the windshield, completely obstructing my forward visibility and creating an extremely dangerous situation. I was able to safely pull over without causing a collision, but the vehicle sustained extensive damage and was declared a total loss by my insurance company. During the same service visit in which the engine was replaced, the dealership recommended replacing the hood latches, but I declined that repair. Hyundai later informed me that the hood latching system was functioning properly after the engine replacement and that the vehicle passed its post-repair inspection and road test. Approximately one mile after leaving the dealership following the engine replacement, the hood unexpectedly opened while I was driving. There were no hood-ajar warnings, warning lights, or other indications that the hood was not properly secured before the incident. The sudden loss of visibility created a serious risk of a crash that could have resulted in severe injury or death. I am submitting this complaint because I believe this incident represents a significant vehicle safety issue that should be investigated.

The contact owns a 2015 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the panoramic sunroof detached from the vehicle. The hazard lights were activated, and the vehicle was pulled over to the shoulder of the roadway. The contact attempted to close the cover and was able to close it halfway. The contact stated that on a separate occasion, while driving at an undisclosed speed, the failure reoccurred. The contact pulled over to the side of the road and attempted to close the cover, but the cover failed to close. The contact drove the vehicle while holding the sunroof cover with the other hand. The contact stated that the wind kept lifting the detached panoramic sunroof. The vehicle was taken to a collision center to reattach the panoramic sunroof. The employee removed the panoramic sunroof and placed the sunroof on the passenger seat. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. Upon further investigation, the contact related the failure to NHTSA Campaign Number: 16V726000 (VISIBILITY). However, the VIN was not included in the recall. The manufacturer was not made aware of the failure. The failure mileage was unknown.

We are the sole owners of the 2015 Hyundai Sonata. Over the years the dashboard has deteriorated and developed cracks along the entire length, including over the area of the passenger airbag. We are currently concerned as to what would happen in the event of an accident that would trigger the air bag causing the dashboard to explode and send splinters all over the place, possibly causing severe damage to the passenger. I took the vehicle to Lehman Hyundai and they could not give me a definitive answer as to whether this was a dangerous situation or not. They gave me an oral estimate of $3,500 just for the part, and who knows what the labor costs would be. Whether I end up donating, gifting or selling the car, I am truly concerned about the safety of this vehicle and the condition it is in.

My passenger occupancy mat señor is not working. It has been replaced by Hyundai several times and was a part of a recall. It was replaced in 2006 and 2007. They installed a new version of the senor mat, and the mat senor is defective again. I called Hynindia of America, and they said even though it was a recall and they fixed it as a recall fix, they said that they are no longer responsible. Is that the case?

The contact owns a 2015 Hyundai Sonata. The contact stated that while driving at lower speeds, the steering wheel became difficult to steer in either the left or right direction. The Traction Control, Power Steering, and the high-beam warning lights were illuminated. The vehicle was taken to a local independent service center, where it was diagnosed with error codes: C167286, C126008, C136008, C126002, and C168808. The vehicle was not repaired. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 195,000.

We have had issues with tires not wearing equally and tears on the inner tire/s shortly after replacing. This has happened twice so far. This has lead to air loss, severe vibration, and pulling while driving. Most recently, both back tires were losing air with one back tire having a structural issue on the inner portion of the tire making it unsafe to drive. We had just put on new tires in 1/2024 and had to replace one of those before this issue because of a tear on the inner portion. Both back tires were replaced and rotated. Severe vibration and pulling occurred. We took it in to have balancing and an alignment done only to find out that all 4 rims are bent to varying degrees on the inner lip that meets with the tire. All 4 tires were wobbling significantly during the service to balance resulting in the inability to balance the tires. As there hasn’t been any occurrence that would have caused all 4 rims to bend in the exact same place, and reading about the defects of the coating on the rims as well as other wheel related issues, we felt it necessary to file a complaint. Living in a state where there is salt put on the roads as well as salt in the snow itself, peeling and premature wear to the rims due to the lack of a safe and sufficient coating, exposes the metal to the elements and excessive salt during the winter months. This in turn weakens the metal making it susceptible to bend and sustain damage it would not otherwise sustain. We now have to replace all 4 rims to eliminate the vibration and alignment issues.

Multifunction box is in the steering column that controls your lights, signals, I put my turn signal on right or left at night and my lights go out,but they come back on.also I have zero warning lights on my dashboard for when something happens it let's you know,well I have none. Hyundai of California says it's not unsafe.it should be a recall because it's a thousand dollars for update..

I brought this car brand new at ABC HUNDUIA IN Las Vegas NV I now like in NY And my engine making a loud winning noise as I steer and the seat drivers side does not retract back into place .I just spent over 3 grand to fix other issues A/C cost over 3 grand but they never fixed what I requested. Please help me Thank you [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I own a 2015 Hyundai Sonata and have an issue with dash pad, the passenger side air bag has split at the airbag seam and has traveled to the drivers side. If the passenger airbag deploys, I could see some severe injury to the passenger side occupant when the airbag deploys after the cover detaches from the rest of the dash pad. The lifespan of any safety system component is 15yrs according to NHTSA

The truck button has disintegrated twice now and needs a manufacturers recall.

This complaint concerns a repeat failure of both front CV axles on my 2015 Hyundai Sonata. The CV axles and boots were replaced by Gettel Hyundai of Charlotte County using OEM parts in November 2024. The same components failed again just 7,876 miles later in January 2026; requiring a second full replacement. A CV axle replaced with factory OEM parts by a certified Hyundai tech should not fail within 7,876 miles under normal driving conditions. This pattern of repeat failure indicates either * A defect in the OEM replacement parts supplied by Hyundai * An installation defect at the authorized dealership * An unresolved underlying mechanical condition that causes accelerated CV axle wear The rapid repeat failure represents a potential safety hazard. CV axle failure can result in sudden loss of drive power, difficulty controlling the vehicle, and in severe cases, wheel separation --all of which create dangerous conditions for the driver and others on the road. Chronological Timeline of Events: Nov 5, 2024 55,579 miles; both front CV axles replaced by authorized Hyundai dealership using OEM parts. Labor and parts performed per Hyundai standards. Jan 29, 2026 63,451 miles Same CV axles failed again. Second replacement performed at same authorized Hyundai dealership. Total repair cost $3227.16 paid out of pocket by me. Feb 16, 2026 Hyundai Motor America denied goodwill reimbursement request (Case #XXX), citing the malfunction being out of time in service of the vehicle. Reported to Hyundai Motor, their response did not address the repeated nature of failure, the short mileage interval, or the possibility of a defective OEM part or improper installation. I believe the NHTSA should be aware of this pattern and investigate other 2015 Hyundai Sonata owners have reported similar rapid repeat CV axle failures, which could indicate a systemic defect in either OEM parts or dealership repair procedures. 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 depressing the brake pedal, the vehicle veered to the right. The vehicle was taken to the local dealer and the brake rotors were modified, and the failure was corrected. Additionally, while driving at speeds over 65 MPH, the front driver’s side of the vehicle was shaking and vibrating abnormally. The cause of the failure was not yet determined, and the vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was 70,000.

215/55 R 17 My right rear tire has been losing air for at least 6 months. My tire pressure light is constantly on. I had my tire inspected and was told all 4 tires are compromised. The mechanic told me that my tires were wavy??? and that the tread inside my tires were damaged and I needed to replace all 4 tires. He also said my car would not pass inspection because of this defect in the tires. I feel my safety is at risk because of the inconsistent pressure that the tires may blow at any time.

TL* THE CONTACT OWNS A 2015 HYUNDAI SONATA EQUIPPED WITH HANKOOK KIN ENERGY TIRES (NA), SIZE: 205/65/R16 (NA). WHILE DRIVING APPROXIMATELY 70 MPH, THE REAR PASSENGER SIDE TIRE BLEW OUT. THE CONTACT PULLED OVER TO THE SHOULDER OF THE ROAD. THE VEHICLE WAS TOWED TO THE HOUSE. THE CONTACT TOOK THE TIRE TO THE DEALER AND THE CONTACT WAS ADVISED TO TALK TO THE TIRE MANUFACTURER. THE TIRE MANUFACTURER WAS NOTIFIED OF THE FAILURE. THE TIRE WAS REPLACED AT THE OWNER'S EXPENSE. THE DOT NUMBER WAS UNKNOWN. THE APPROXIMATE TIRE AND VEHICLE FAILURE MILEAGE WAS 16,000.