2023 Hyundai Sonata Problems

I own a 2023 Hyundai Sonata SEL. Over approximately three years, the vehicle experienced four separate incidents involving sudden loss of engine power and recurring fuel injector/powertrain problems. Three of these incidents occurred while the vehicle was being driven on interstate highways, creating serious safety concerns. The first incident occurred on XXX, on [XXX] [XXX]. My daughter was driving the vehicle at the time when it suddenly lost power while traveling on the interstate. She had to maneuver the vehicle to the shoulder under unsafe traffic conditions. The second incident occurred on XXX, on [XXX] near [XXX]. I was driving the vehicle when it again experienced sudden loss of power while traveling at highway speed. The third incident occurred on XXX, in [XXX]. The vehicle experienced another significant power-loss event and required roadside assistance. The fourth incident occurred on XXX, on [XXX]. The vehicle again experienced a sudden loss of engine power while I was driving on the highway. Despite multiple repair attempts, including repairs related to the fuel injectors, the same or substantially similar power-loss problem continued to recur. Because the vehicle has repeatedly lost engine power while being driven, including multiple incidents at interstate highway speeds, I believe this recurring condition presents a serious safety risk. I am reporting these incidents so NHTSA can evaluate whether this may represent a broader safety-related defect affecting this vehicle model. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2023 Hyundai Sonata. The contact stated that while driving approximately 15-40 MPH, the vehicle was sputtering and shaking abnormally. The failure was a recurring failure. The contact associated the failure with NHTSA Campaign Number: 25V796000 (Fuel System, Gasoline); but the VIN was not under recall. The dealer was contacted; however, the vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 86,500.

I own a 2023 Hyundai Sonata SEL. Over approximately three years, the vehicle experienced four separate incidents involving sudden loss of engine power and recurring fuel injector/powertrain problems. Three of these incidents occurred while the vehicle was being driven on interstate highways, creating serious safety concerns. The first incident occurred on XXX, on [XXX] [XXX]. My daughter was driving the vehicle at the time when it suddenly lost power while traveling on the interstate. She had to maneuver the vehicle to the shoulder under unsafe traffic conditions. The second incident occurred on XXX, on [XXX] near [XXX]. I was driving the vehicle when it again experienced sudden loss of power while traveling at highway speed. The third incident occurred on XXX, in [XXX]. The vehicle experienced another significant power-loss event and required roadside assistance. The fourth incident occurred on XXX, on [XXX]. The vehicle again experienced a sudden loss of engine power while I was driving on the highway. Despite multiple repair attempts, including repairs related to the fuel injectors, the same or substantially similar power-loss problem continued to recur. Because the vehicle has repeatedly lost engine power while being driven, including multiple incidents at interstate highway speeds, I believe this recurring condition presents a serious safety risk. I am reporting these incidents so NHTSA can evaluate whether this may represent a broader safety-related defect affecting this vehicle model. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

This is an extremely common issue plaguing Hyundai & Kia vehicles with the Theta III 2.5L Turbo engine, Such as Kia K5 GT, Hyundai Sante Fe, Hyundai Santa Cruz, & Hyundai Sonata N-Line. Its a failing ITM (integrated thermal management) unit or otherwise known as an ITMS unit. There is a rod within the ITM that prevents proper control of the flow of cooling the oil and engine coolant of the engine. Results in Cooling issues, such as a cold lower radiator hose while the engine is hot, or 'limp mode' during acceleration, that causes a sudden loss of power while trying to merge on the expressway. There has been other Kia models and years that have had TSB's related to fixing this issue, but Hyundai has released nothing. I have uploaded an example of one of the TSB's that do not apply to my car. Technical symptoms often include: Fans running 100% full duty (high) while the lower radiator hose stays cool. Or Fuel dilution or a 'rich' running engine. Because the engine is overcooling that keeps the car's fueling rich and in a open loop mode affecting emissions and contaminating oil. Personal Details of exactly what happened when i noticed mine was failing. I ran home on my lunch break, and while accelerating on a ramp to get up on a highway, my car started beeping and flashing "Engine Overheated" and i immediately let off the gas with preparation to pull over. The second i left off the gas, the coolant temp within 1-2 seconds went from a little over 3/4 the way up the gauge back to normal a little below half temp. I resumed driving a 3 mile drive back to work, with it showing normal temps the rest of the way. I popped the hood when i got to work to see if coolant was low, and it was completely normal, a little over halfway between the min/max lines. The car continues to run hot, often with the cooling fans running at 100%.

I own a 2023 Hyundai Sonata SEL. Over approximately three years, the vehicle experienced four separate incidents involving sudden loss of engine power and recurring fuel injector/powertrain problems. Three of these incidents occurred while the vehicle was being driven on interstate highways, creating serious safety concerns. The first incident occurred on XXX, on [XXX] [XXX]. My daughter was driving the vehicle at the time when it suddenly lost power while traveling on the interstate. She had to maneuver the vehicle to the shoulder under unsafe traffic conditions. The second incident occurred on XXX, on [XXX] near [XXX]. I was driving the vehicle when it again experienced sudden loss of power while traveling at highway speed. The third incident occurred on XXX, in [XXX]. The vehicle experienced another significant power-loss event and required roadside assistance. The fourth incident occurred on XXX, on [XXX]. The vehicle again experienced a sudden loss of engine power while I was driving on the highway. Despite multiple repair attempts, including repairs related to the fuel injectors, the same or substantially similar power-loss problem continued to recur. Because the vehicle has repeatedly lost engine power while being driven, including multiple incidents at interstate highway speeds, I believe this recurring condition presents a serious safety risk. I am reporting these incidents so NHTSA can evaluate whether this may represent a broader safety-related defect affecting this vehicle model. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2023 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the transmission shifted into neutral(N) and failed to shift into park or drive on three occasions. The vehicle was restarted. After restarting the vehicle, the vehicle was shifted into drive, and the contact continued driving. The message that the vehicle could not be shifted into other gears was displayed. The vehicle was originally purchased in another state. The vehicle was taken to the local dealer to be diagnosed. The dealer determined that the battery and fuel injector pump needed to be replaced. The vehicle was repaired; however, the failure recurred. The manufacturer was not contacted regarding the failure. The failure mileage was approximately 50.

Reported this previously, but more information was gathered, thanks to collision mechanic who guessed immediately when he heard 2023 hybrid Sonata - he said "they're notorious for it." Was at a stand still in a parking space/lot I know well. Cautious driver, watch my speed, very aware of other drivers, quick reaction time. Incident mid day, no pedestrians, distractions, no moving traffic. Vehicle doors shut, seat belt on. Not on incline. Pulled into parking spot I use weekly, spot has parking curb. Was at a full stop. Realized I had not pulled into the spot quite far enough, and attempted to inch vehicle forward. (Do not recall any warning lights, but this car usually alerts at literally anything - even shadows.) Very lightly applied gas to inch forward, slowly. Felt slight "scrape" of undercarriage on the parking curb. Put car in reverse, lightly applied gas to inch back. Car did not rev, no screeching tires, it was at a standstill previously. Was in Eco mode. All seemed normal, until vehicle suddenly launched UP the parking curb, full force, and into a building pillar directly ahead. The car never moves with that much force, I'm not a pedal-to-the metal driver. Eco mode on. No airbag deployment, injuries, etc. Sheriff took report for the building, simple incident. I couldn't make sense of it. I know how overly cautious I am while parking, what I do, and don't do. Took responsibility, but was still analyzing a week later, and explained what I remembered to the mechanic. He guessed right away. Said Sonatas were notorious for it. He said they're known for randomly applying the ebrake unexpectedly - and also randomly releasing the ebrake - and aggressively (and silently) switching from electric to gas when met with resistance, aka the parking curb. Insurance totalled the car. 2.5 years old, 17k miles. This was my 3rd Hyundai in 20 years, others were great. Discovered 40,000 Elantra hybrids, same year as my Sonata, were recalled due to "unintended acceleration."

Car was parked, full stop, doors shut, seatbelt on. Foot on brake. Car then seemed to lurch forward by itself forward hitting parking cement block. Put in reverse to back away and car stayed still...then I tapped the gas again to back up and insted vehicle plowed forward.instead.of reverse ...went over the parking block and hit concrete beam in front, when the car should have backed up in reverse. I'm a person who drives speeed limits, and ulta careful when i drive, and parked at this place/spot for years. This has never happened not sure why it did. No injuries or other people involved thank god, but scared the heck out of me. Wracking my brain, my recalls and software and service appts are up ro date.Nothing out of ordinary that day. I'm confused and shaken, why the first lurch forward and why did going in reverse move it forward? ugh. It drove home fine. Commute to work daily for years, no issues. All I can guess is gear didn't click to reverse and was somehow in drive? Ive been going over the possibilities in my head for human error but they dont make sense - again I've been driving for 40 years. If it happens to other models, would love to know! Car will go to repair tomorrow as "my fault" via insurance, hoping they can see more if any error codes, to at least say if Reverse didn't engage or something else happened. May have been human error but it's so out of the ordinary for me. Thanks!

Battery Management System completely exhausting the 12V battery resulting in the car acting as if it has no power. When this happens, you can't unlock the door or open the trunk. On two separate occasions, I have encountered a complete loss of power in my Sonata Hybrid, preventing me from unlocking the trunk or doors upon returning from extended trips. The first incident occurred after a ten-day absence last Fall, and the most recent was on Saturday, March 14, 2025. During the latest incident, I returned from a seven-day trip and found my vehicle parked at Orlando International Airport. Upon approaching the car, I anticipated being able to unlock the trunk, load my luggage, enter the vehicle, and drive home. However, once again, the vehicle was unresponsive. Accessing the car required removing the cap from the door handle and manually inserting the key, a process that took approximately ten minutes, which was particularly inconvenient and concerning in an airport parking lot. This situation was even more challenging considering I am a [XXX] woman of smaller stature attempting to resolve this issue alone at night. I believe this poses a serious safety concern for all owners under similar circumstances. Following the incident last Fall, I brought my Sonata Hybrid to Key Hyundai in Jacksonville. I was informed that this is a known issue for which there is a recall; however, my vehicle model year is not included in the affected range. It was suggested that I would need to manage this problem independently. I believe this recurring issue represents a known vulnerability that could potentially expose Hyundai and its dealerships to liability should an owner suffer harm while addressing this malfunction. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

1. All safety features related to the back up camera, EPS, Traction Control, Lane Assist, Active Cruise Control, Automatic High Beam, Forward Collision Avoidance and more. 2. Loss of all safety features and then sudden restoration of EPS would cause swerve into oncoming lanes or into neighboring lanes and/or ditches. 3. Yes the problem has been reproduced, repeatedly in cold weather and while the dealership has had it in for repairs. 4. No, but the dealership has contacted the manufacturer for repair advice. 5. Yes, every time. I have photos of my dash with the indicating lights on. 10/2/23.

Recall 286 my vehicle suffered from this causing heat module failure misfire in cylinder 2 and high pressure in gas tank. Sports Hyundai had previously done a 180 day repair under recall 9b1 for an expanded gas tank after the repair the car suffered from the updated recall 286 . I brang to the dealership 4 times with check engine and misfires and limp mode between 57k and 68k they refused to fix the car under recall 286 and cleared all the codes and continued to make me leave in a unsafe car. On February 14th it sport Hyundais negligence was the direct cause of an auto accident were the car was unable to move out the way because of lack of power /limp mode. I begged them in the final days of me having the car to fix it and saying I didn’t feel safe and they wouldn’t without an extensive amount of money I could not provide . I’m currently filing a claim with Hyundai consumer affairs and the dca in Newark and also my senators office and I have a lawyer also who might help I wish to report this to the NHTSA.

See attached document for complaint

Since I have had the car, I would have to check my invoices for exact mileages, I have changed my brakes 4 times now. I only have 40k miles on the vehicle. This is very bizarre to me since I have owned a 2020 Hyundai sonata SEL convenience prior to this and never once changed the brakes. I have also changed my rotors once, resurfaced them another then, and I am in the process of changing them again. Now to this day, my calibers are shot. They will take 2 months on back order to come in from Korea. Maybe Hyundai needs to look into N lines in specific as I have read many people complaining about the same thing. It's 40k miles and I am just now needing to change my rear brakes, seems pretty reasonable. Something is very wrong with this car.

Forward Collision Warning appeared, vehicle lost power and would not accelerate. Vehicle kept loosing power. Multiple codes appeared. I am an ASE certified mechanic, so I went to my own business to get my scanner and there was a list of codes. Vehicle is currently at dealership and they are tracking down issues. Currently blaming an ECM but unsure. This is the second vehicle I have had this exact issue with. I have video that it won't allow me to upload of all the codes. I have a video of a previous issue, with a different vehicle. It's a 2023 Hyundai Santa Fe

1. All safety features related to the back up camera, EPS, Traction Control, Lane Assist, Active Cruise Control, Automatic High Beam, Forward Collision Avoidance and more. 2. Loss of all safety features and then sudden restoration of EPS would cause swerve into oncoming lanes or into neighboring lanes and/or ditches. 3. Yes the problem has been reproduced, repeatedly in cold weather and while the dealership has had it in for repairs. 4. No, but the dealership has contacted the manufacturer for repair advice. 5. Yes, every time. I have photos of my dash with the indicating lights on. 10/2/23.

On two separate occasions, one at @9500 miles and the next at @19,000 miles the car engine started shaking and lost all power while driving. Unable to steer car. Both times towed to dealer and they say it needs new spark plugs and need to clean cylinders. They do not know root cause of problem and have not done any testing of the engine, no leak/compression testing. Dealer refuses to cover cost of repairs saying out of warranty but cannot give any assurances this won’t happen again. I’ve requested they contact Hyundai engineers to find out what’s causing this and, to date, they’ve done nothing. Vehicle is unsafe to drive and is still at dealership with no reason to underlying issue.

The brake rotors are faulty and become warped at 9k mile I now have 27k and are extremely warped causing braking issues at higher speeds. I have been waiting over two months for new rotors from the dealer with no word as to when they will arrive. If the vehicle is left un-driven for a couple days the rotors will become rusted. Even the brand new vehicles in the Hyundia showroom are covered in rust. The suspension of the rear shock are extremely weak and bottoms out on the smallest rut. Cornering I’m the vehicle is subject to enormous amounts of whee hop which could result in an accident.

Hello, I have Hyundai Sonata 2023. The fuel tank of this car is expanded on [XXX]. I have never heard about this issue to any cars. I took my car to dealership they said they don’t know why this happened and they said they cannot fix it, my car at the dealership more than a month. I have created a case with Hyundai corporate office in CA, it’s been a month since this case was created and I could reach out to my case manager only twice for this period of time. They are keep saying they are working on it, but no results they don’t even look at my car. Today I barely could reach my case manager and she told me that this is not under warranty and I will need to fix it out of my pocket. When I bring the car to the dealership they told me this not under warranty since warranty was up to 60k miles, I have 90k I asked them to fix it and I will pay but they said they don’t know how to fix it. Today I have researched and found that this issue is really common among Kia K5 and Hyundai Sonata’s 2021 2024, I will provide a link here: [XXX] Please check this link and you can see that most of the cars fuel tanks are expanded and back seats popped up. I have same exact problem. Kia asked drivers to inspect the cars with this issue and they said they will fix it for free since this is fuel tank defect. But what should I do with my Hyundai Sonata. I have same exact issue as you see at the link I have provided. I had powertrain DTC PO451 since march of this year dealership said just check if gas cap is on properly, but this caused this issue I see Hyundai will not help me it will almost 2 month I don’t have my car and I am still paying for it, please let me know what I can do Thank you! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Instrument cluster lighting is too bright even on lowest setting. Combined with poor side visibility from headlamps it is easy to hit object or pedestrians when turning on unlit areas. Have run over a curb three times and damaged two wheels because they can't be seen from the overly bright instrument lighting at night.

The contact owns a 2023 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the air bag warning light illuminated. Additionally, the contact stated that the rear passenger’s and rear driver's side doors were leaking. The vehicle was taken to the dealer however, the mechanic was unable to duplicate the failure. The manufacturer was made aware of the failure. The failure mileage was approximately 140.