2020 Hyundai Sonata

The contact owns a 2020 Hyundai Sonata. The contact stated that while the vehicle was parked, the contact became aware that the frame on the front driver's seat was cracked. The contact inspected the seat. The contact lifted the cushion and became aware that the bolts were cracked. There were no warning lights illuminated. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The failure mileage was 34,458.

My 2020 Hyundai Sonata has a recurring and dangerous defect involving sudden deceleration while driving. Without warning, the car abruptly slows to ~10 mph—often on the highway—while numerous dashboard warning lights activate. This poses an extreme safety risk to me, my passengers, and other drivers, as it forces me to maneuver off the road to avoid being hit. The issue began in January 2021, just five months after I purchased the car new. It has occurred repeatedly and unpredictably since then. I have taken the vehicle to Hyundai-authorized dealers for repair on five occasions (January 2021; December 2021; January 2022; November 2024; and February 2025), but the problem has never been properly diagnosed or fixed. In November 2024, the issue occurred immediately after I picked the car up from the dealership when they told me it was fixed and ready to drive. This most recent occurrence (February 2025) before tonight's incident on April 6, 2025, the dealer had my vehicle for over a month. During this time, communication was seldom initiated by the dealer. Now the problem recurred less than 55 hours after picking the vehicle up from the Hyundai certified dealer, who told me the issue was fixed and the car looks and runs great. Unfortunately I found myself in this dangerous situation despite the dealer's reassurances and Hyundai's involvement overseeing the repair process. The unsafe, defective Sonata is currently in my possession as I figure out next steps. Each incident is accompanied by multiple warning lights (e.g., check engine, ESC, etc.) but the dealer represents that no consistent diagnostic codes have been found. I’ve also found multiple similar complaints from other Sonata owners on the NHTSA site, suggesting this may be a broader issue. This unresolved defect has made the vehicle unsafe to drive and caused significant emotional distress. I no longer trust the car or the assurances from Hyundai or the dealer that it is fixed.

My 2020 Hyundai Sonata has a recurring and dangerous defect involving sudden deceleration while driving. Without warning, the car abruptly slows to ~10 mph—often on the highway—while numerous dashboard warning lights activate. This poses an extreme safety risk to me, my passengers, and other drivers, as it forces me to maneuver off the road to avoid being hit. The issue began in January 2021, still with less than 4,000 miles and just five months after I purchased the car new. It has occurred repeatedly and unpredictably since then. I have taken the vehicle to a Hyundai-authorized dealer for repair on five occasions (January 2021; December 2021; January 2022; November 2024; and February 2025), but the problem has never been properly diagnosed or fixed. In November 2024, the issue occurred immediately as I drove off the dealer's lot, having been assured the vehicle was repaired and safe to drive. The most recent visit lasted over a month, yet the dealer could not replicate the problem and returned the car to me in early April 2025, without a clear resolution. The vehicle is currently in my possession and available for inspection. Each incident is accompanied by multiple warning lights (e.g., check engine, ESC, etc.) but no consistent diagnostic codes have been found. I’ve also found multiple similar complaints from other Sonata owners on the NHTSA site, suggesting this may be a broader issue. This unresolved defect has made the vehicle unsafe to drive and caused significant emotional distress. I no longer trust the car or the assurances from Hyundai or the dealer that it is fixed.

On or about November 13, 2024 our Hyundai Sonata 2020 gas tank almost exploded. We drove our vehicle to a dealership so that it could be checked because we kept hearing something that sounded like a loud pop / thumb underneath our vehicle. We had already been receiving notifications of a powertrain issue with the vehicle for years (without the dealership resolving the issue). So we were taking the vehicle in for numerous reasons when, the minute we drove our vehicle into the service bay (of a new and unrelated dealership) we were told that Hyundai's Corporate branch has ordered our vehicle grounded and told us we COULD NOT LEAVE with our vehicle or drive our vehicle off the dealership's lot. We were advised that our vehicle had almost exploded and that we were lucky to have brought the vehicle in. We were told that our vehicle should have never left the lot the day we purchased it brand new. We were told that our vehicle's backseats had detached and separated away from the frame of the vehicle. Our vehicle has been at the dealership since the day of the incident (e.g., on or about November 13, 2024). Our vehicle is still under factory warranty and powertrain warranty and Hyundai was not given us an end in sight or advised the public of the issue with their vehicles. WE were told that the vehicles needs repairs such as: 1. The vehicle needs the fuel tank assy and all of the parts for the tank, check valve, and campaign sticker: Please see TSB: 24-01-02OH

The contact owns a 2020 Hyundai Sonata. The contact stated while driving at 35 MPH, the vehicle made a booming sound. There were no warning lights illuminated. The contact then started to hear the sound outside the vehicle and noticed that the vehicle was losing gasoline very quickly. The vehicle started to stall, and the gas tank was almost empty when the contact arrived home. The vehicle was then taken to a dealer where it was diagnosed with floor damage, and the floor damage showed deformation on the rear passenger’s seat, and the fuel cover had popped off due to the deformation, which caused the noise in the cabin. The vehicle was towed to another dealer where the vehicle was repaired, with a new fuel pump cover, and the rear seats were replaced. On another occasion, the fuel pump failure reoccurred. The manufacturer was made aware of the failure. The failure mileage was approximately 77,524.

I took my car in for a standard oil change and tune up. They found out that the fuel tank had expanded to the point where it caused significant damage to the metal frame. The Hyundai dealership sent it to the local body shop for an estimate for the frame, they sent it back because the dealership hadn't removed the gas tank, then the dealership sent it back to the body shop. It's been 3+ weeks, my car is still in the shop, and I haven't received any indication of whether my car is able to be fixed. The dashboard never displayed any warning messages and there were no symptoms of the problem. I had no idea the gas tank had expanded and could've caused an explosion or fire.

My 2020 Hyundai Sonata SE (82931 miles at the time) has experienced repeated issues with the front passenger window. The window would get stuck while attempting to operate it, accompanied by a loud, crushing noise. Upon visiting the dealership, I was informed that the issue stemmed from the window regulator, which had failed internally and required replacement. Additionally, my girlfriend, who owns a 2020 Hyundai Sonata SEL with approximately 31,000 miles, is now facing the exact same problem with her vehicle’s front passenger window. After conducting research on online forums, I discovered that several other 2020 Hyundai Sonata owners are reporting similar issues with their window regulators. This suggests that the problem may not be isolated to just one or two vehicles but could point to a potential widespread defect. Although this issue primarily affects the operation of the window, it could lead to safety risks if the window gets stuck in an open position, exposing occupants to potential theft, weather elements, or other hazards. I am requesting the NHTSA investigate this matter to determine if the window regulator failure in 2020 Hyundai Sonata models is a systemic defect that warrants further action, such as a recall or manufacturer response. I am happy to provide additional information or documentation, such as repair invoices, dealership statements, or records of the issue. Thank you for addressing this concern.

Been having an issue with a check engine light and a popping noise in the from the front of the vehicle for about two years. Took it to the dealership more than 3 times over that span and every time they discovered it was caused by something different..during the July of 2024 while driving on the interstate a loud pop noise was made from the back and my children complain about the seat lifting…shortly after I went to get gas and a full tank was more gallons than usual 14 increased to 17g…. I once again took it to the dealer for the issue of the gas tank expansion and pop but found nothing. No more than a week later my car would hesitate to accelerate and progressively got worse. On 12/27/24 I took it to the dealer and they discovered my gas tank was expanded and was unsafe to drive leaving me without a vehicle.as of 1/04/2025 I still have no solution.