2023 Hyundai Sonata

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%.

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)

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.

Vehicle WITHOUT WARNING will start to jerk then go into “limp” mode. Pressing on gas pedal makes the revving noise but with not physical movement made. This has happened on MULTIPLE occasions (13 times in 4 months) including in the snow and on the interstate while driving at 70mph where no shoulder is available to pull over. Car was taken to dealership 3 different times with no actual diagnosis, tests were ran all 3 times with nothing. Eventually the 3rd time at the dealership I was told the transmission was being replaced although they were not sure what actually caused the issue (this is written in the service report by the rep/mechanic). CAR REMAINS UNSAFE AND UNRELIABLE. Livelihood of myself, family and other drivers is at risk EVERYTIME I put the car in drive due to this mechanical issue. NO WARNINGS NO POWER NO FIX.

My Hyundai Sonata 2023 is experiencing two recall codes. The first one was 9b1 which was resolved, but the other one is indefinite which is 286. I dropped my car off on December 4 of 2025 and a month later Hyundai’s corporate team reached out to discuss the state of my car. They asked me for things such as the payoff balance of what I owe through CarMax who I’m financing the car from, they asked me the mileage on the car, the registration and the lien. They then told me they would provide me with an update by certain dates it’s been over two months and I haven’t received any updates. The car shop called me to come pick up my car because one of the issues was resolved, but after reviewing the recall code 286 and seeing that there is very much so a safety risk when driving the car, I ultimately chose to leave the car with Hyundai. Hyundai has been unsuccessful with providing me with the solution. I’ve waited two months almost 3 months and I believe that this vehicle is a lemon and I need a solution. Hyundai took back the loaner, I have nothing now and they keep telling me they’re going to follow up, but have not followed up with anything I need help. I don’t want to risk my life, driving the car and being paranoid that it could catch on fire and harm me or other people driving in it please help.

My car was having an issue where it was losing all the coolant, causing my engine to overheat twice while driving down the highway. Unfortunately I couldn't find a leak anywhere and there was no fluid leaking in my garage. I lost an entire reservoir of coolant overnight. After taking my car to the dealership to get repaired, I was told that it was leaking my coolant into the exhaust system and burning it up. I was also told "it was a know issue, they had a bulletin from Hyundai on how to fix the problem, and Hyundai completely redesigned the part to stop the leak and it had to be special ordered." I was without my car for a week and left with a $1300 bill as apparently it was not covered by my warranty. I have no idea how a known issue is happening so frequently that requires a nationwide bulletin and a part redesign, yet somehow is recalled. Especially considering it left me stranded on the side on the side of the highway in Indiana during a snow storm but someone seriously needs to investigate it.

I am reporting a serious coolant system defect on my 2023 Hyundai Sonata Hybrid with about 13,500 miles. The vehicle develops an internal coolant leak while driving. Coolant burns off and white steam/smoke comes out of the exhaust, especially during acceleration. When this happens, the coolant level drops quickly, the interior heater stops working, and the car soon displays an engine overheating warning, forcing me to stop driving. This has happened multiple times and makes the vehicle unsafe. When I checked under the hood, coolant was at a low/empty level after overheating events. The car becomes undriveable once the alarm appears. I took the vehicle to a Hyundai dealer, and even though the vehicle is only 2 years old, they told me it was “out of warranty.” I had to pay about $1,500 for repairs, and since the dealer refused a loaner, I paid $250 for a rental car. I called Hyundai USA on 9/13/2025 and opened Case Number XXX. Hyundai acknowledged they are aware of coolant issues on the Sonata Hybrid but said no recall exists. This issue appears widespread. Many other owners report the same symptoms: white exhaust steam, coolant smell, coolant loss, no interior heat, and engine overheating. Hyundai released TSB 23-EM-009H, describing a failure where coolant leaks internally in the Exhaust Heat Recovery System (EHRS), causing white smoke and overheating—matching my symptoms exactly. This defect is a safety hazard because overheating can occur suddenly while driving, risking engine damage or breakdown in traffic. I request NHTSA investigate this issue as a potential recall-level defect on the 2023 Sonata Hybrid. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The fuel injectors failed on my Hyundai Sonata in two instances. Once on 5/23/24 and once on 9/7/25. During the first instance, I was driving on a local road when the accelerator stopped working and the engine started sputtering. We were fortunately able to stop at a nearby parking lot before the engine completely stopped working. During the second instance, I was also driving through a local road when the accelerator stopped and the engine started sputtering again. This time, we weren't able to reach a safe stopping point and the engine died on the road. My family was with me at the time, so we had to push the car in neutral to the closest safe space. In both cases, our safety and the safety was others was put at risk as the car become unable to accelerate, and the car stops moving. We had to get out on the road and push the car with oncoming traffic. The problem was confirmed by the dealer in both cases, and they replaced the fuel injectors in both cases. So far, they've replaced 3 out of the 4 fuel injectors so I still drive in fear of another fuel injector causing a breakdown while I'm driving. There were no warnings or symptoms prior to the failure so there was no way to know to stop driving and to stop in a safe spot. We were fortunate to be able to move the car to a safe place for both instances, but if this had happened on the highway or secluded location, our lives could've been at risk. I've requested Hyundai to replace the last fuel injector but they're refusing to do so. I only feel safe driving in local roads or short highway trips as I fear for the reliability of my car, my safety, and the safety of others.