2020 HYUNDAI SONATA

EQUIPMENT:OTHER:LABELS

Hyundai Motor America (Hyundai) is recalling certain 2020 Sonata vehicles produced between October 22, 2019 and February 13, 2020. The tire pressure label inside the driver's door and the owner's manual state an incorrect tire size. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 110, "Tire Selection and Rims."

Risk: The incorrect tire information may mislead the vehicle owner to install the wrong tire size, potentially affecting vehicle handling, increasing the risk of a crash.

ENGINE

The contact owns a 2020 Hyundai Sonata. The contact stated that the vehicle hesitated while depressing the accelerator pedal, with the check engine warning light illuminated on the instrument panel. The vehicle was taken to several independent mechanics and dealers to be diagnosed; however, the cause of the failure was not determined. The contact stated that one mechanic replaced an unknown sensor, but the failure returned soon after the repair. The manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was approximately 101,000

POWER TRAIN

The contact owns a 2020 Hyundai Sonata. The contact stated that the vehicle hesitated while depressing the accelerator pedal, with the check engine warning light illuminated on the instrument panel. The vehicle was taken to several independent mechanics and dealers to be diagnosed; however, the cause of the failure was not determined. The contact stated that one mechanic replaced an unknown sensor, but the failure returned soon after the repair. The manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was approximately 101,000

SEATS

In early May 2025 while driving around 40mph, I heard a very loud pop which startled me. Pulled over and looked back and noticed my backseats were push up out of place. I attempted to put the seat back into place but it wouldn’t fit into the latch anymore. The framing underneath the seats looked pretty damaged so I took it to a local mechanic. After doing some research, he found information for a check valve/fuel tank recall (Service Campaign 9B1) and then advised me to go a Hyundai dealership. I attempted to take it to the dealership, whom sent me away after I advised them of what happened. I came back the next day asking them to take a look at while informing them about the recall that could be related. Later that evening, they called and said the issue was directly related to the recall and the repairs would be covered. My car was in their possession for from 5.12.25 to 7.25.25 without any updates or instructions on what is happening. I was told they’re waiting to hear back from Hyundai Manufacturer on how to proceed. They returned my car to me on 7.25.25 stating everything was repaired. On 7.31.25 they called me back stating my tank needs to be replaced and bring the car back asap. My car was again being repaired and was returned to me on 8.25.25. Now my vehicle will not start randomly sometimes. At this point, I’m under the impression my vehicle is no longer safe as all the issues I’ve been facing are fuel related.

FUEL/PROPULSION SYSTEM

In early May 2025 while driving around 40mph, I heard a very loud pop which startled me. Pulled over and looked back and noticed my backseats were push up out of place. I attempted to put the seat back into place but it wouldn’t fit into the latch anymore. The framing underneath the seats looked pretty damaged so I took it to a local mechanic. After doing some research, he found information for a check valve/fuel tank recall (Service Campaign 9B1) and then advised me to go a Hyundai dealership. I attempted to take it to the dealership, whom sent me away after I advised them of what happened. I came back the next day asking them to take a look at while informing them about the recall that could be related. Later that evening, they called and said the issue was directly related to the recall and the repairs would be covered. My car was in their possession for from 5.12.25 to 7.25.25 without any updates or instructions on what is happening. I was told they’re waiting to hear back from Hyundai Manufacturer on how to proceed. They returned my car to me on 7.25.25 stating everything was repaired. On 7.31.25 they called me back stating my tank needs to be replaced and bring the car back asap. My car was again being repaired and was returned to me on 8.25.25. Now my vehicle will not start randomly sometimes. At this point, I’m under the impression my vehicle is no longer safe as all the issues I’ve been facing are fuel related.

STRUCTURE:BODY

In early May 2025 while driving around 40mph, I heard a very loud pop which startled me. Pulled over and looked back and noticed my backseats were push up out of place. I attempted to put the seat back into place but it wouldn’t fit into the latch anymore. The framing underneath the seats looked pretty damaged so I took it to a local mechanic. After doing some research, he found information for a check valve/fuel tank recall (Service Campaign 9B1) and then advised me to go a Hyundai dealership. I attempted to take it to the dealership, whom sent me away after I advised them of what happened. I came back the next day asking them to take a look at while informing them about the recall that could be related. Later that evening, they called and said the issue was directly related to the recall and the repairs would be covered. My car was in their possession for from 5.12.25 to 7.25.25 without any updates or instructions on what is happening. I was told they’re waiting to hear back from Hyundai Manufacturer on how to proceed. They returned my car to me on 7.25.25 stating everything was repaired. On 7.31.25 they called me back stating my tank needs to be replaced and bring the car back asap. My car was again being repaired and was returned to me on 8.25.25. Now my vehicle will not start randomly sometimes. At this point, I’m under the impression my vehicle is no longer safe as all the issues I’ve been facing are fuel related.

UNKNOWN OR OTHER

The ac blower keeps going out I looked it up and a lot of people are having the same problem my ac keep having to buy blowers and they last 1 week before they stop working and they are not cheap my blower keeps going out and my electric in my car keeps messing up when I try to put the ac up it goes up then goes down I don’t know what’s wrong but I looked it up and a lot of people have the same problem

ELECTRICAL SYSTEM

The ac blower keeps going out I looked it up and a lot of people are having the same problem my ac keep having to buy blowers and they last 1 week before they stop working and they are not cheap my blower keeps going out and my electric in my car keeps messing up when I try to put the ac up it goes up then goes down I don’t know what’s wrong but I looked it up and a lot of people have the same problem

POWER TRAIN

My certified pre-owned 2020 Hyundai Sonata has experienced the same critical transmission failure three times since October 2024, creating dangerous safety conditions on highways and city streets. Component/System Failed: Transmission control system with consistent P0768 error code (Shift Solenoid D Circuit Fault). Safety Risks: The transmission failures cause sudden power loss and inability to accelerate while driving, including on highways at speed. This creates immediate danger to myself, passengers, and other drivers when the vehicle unexpectedly loses power during traffic situations requiring acceleration or merging. Problem Reproduction: The failure has been confirmed and reproduced by authorized Hyundai dealership three separate times: - [XXX]: P0768 error, replaced shift control solenoid valve - [XXX]: Same P0768 error returned, replaced entire transmission control unit - [XXX]: Same P0768 error again, replaced complete control wiring harness with extensive dashboard removal Warning Signs: Each failure was preceded by transmission hesitation, rough shifting, and check engine light activation before complete power loss occurred. Manufacturer Inspection: Hyundai technical assistance case #[XXX] was opened for the third failure, acknowledging the recurring nature of this defect despite multiple repair attempts. Assessment: This appears to be a systematic manufacturing defect in the transmission control system affecting safety. Despite three different repair approaches by Hyundai, the identical P0768 error continues to recur, suggesting a fundamental design or manufacturing flaw that creates ongoing safety risks for drivers. The vehicle was out of service for 44 total days across these three incidents, indicating the severity and complexity of this recurring safety defect. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

ELECTRICAL SYSTEM

Without warning, symptoms of the A/C blower not working first occurred a little over a month ago. The fan just stopped blowing altogether (no cold or hot air). After turning the car and the A/C system on and off several times, it began working again and that was it. This past week, the same issue occurred intermittently over 3-4 days. The A/C blower did not come on for a day, the next morning it was functioning, that evening it stopped blowing again, and this went on for several days. Research of the symptoms via YouTube and many online forums, and most importantly confirmation through visual inspection of the fuse box, confirmed that the BLOWER fuse is burning so bad it has melted the connecting port in the fuse box. Whatever the electrical malfunction, the fuse burning and melting is disrupting the connection and ultimately the A/C blower itself. In the dead of such a hot and humid summer, it has been insufferable having to ride around with such inconsistent and intermittent air conditioning.

ENGINE

Whille driving back to Washington state my car check engine light came on and the car shut off while I was driving. I had to have it towed to the nearest city whi ch was Laramie Wyoming. There is no Hyundai dealer had to drive the car once it started back up to Cheyenne Wyoming it was checked. My on star told me there was a problem DTC P0145100 the status had red triangle the DTC power system powertrain and the DTC sub system EMS. I was told and given paperwork by the dealer and was told the car would need major repairs and could take up to 21 days once the work started it would have to he completed there because Hyundai had campaign dealing with my cars problem. I was told I could drive the car home but if the check engine light is flashing pull over immediately. My car is now at the 3rd dealer when I took it to Korum in Puyallup they did not have anyone to diagnose the vehicle only update onboard computer. They said and documented nothing was wrong with the vehicle which is inaccurate. I told Korum about the paperwork from the dealer in Cheyenne they did not so much as look at it. I took the car to the Dealership in Auburn Washington they to had the same findings as Wyoming also there was additional findings which corresponded with the smell of gas and my tank going empty after filling and trying to fill tank because was showing low fuel warning. Pictures were taken of the gas tank which had expanded as well as other pictures of the findings. I was told in Wyoming and Auburn that the code and findings are consistent with the Hyundai campaign

FUEL/PROPULSION SYSTEM

Whille driving back to Washington state my car check engine light came on and the car shut off while I was driving. I had to have it towed to the nearest city whi ch was Laramie Wyoming. There is no Hyundai dealer had to drive the car once it started back up to Cheyenne Wyoming it was checked. My on star told me there was a problem DTC P0145100 the status had red triangle the DTC power system powertrain and the DTC sub system EMS. I was told and given paperwork by the dealer and was told the car would need major repairs and could take up to 21 days once the work started it would have to he completed there because Hyundai had campaign dealing with my cars problem. I was told I could drive the car home but if the check engine light is flashing pull over immediately. My car is now at the 3rd dealer when I took it to Korum in Puyallup they did not have anyone to diagnose the vehicle only update onboard computer. They said and documented nothing was wrong with the vehicle which is inaccurate. I told Korum about the paperwork from the dealer in Cheyenne they did not so much as look at it. I took the car to the Dealership in Auburn Washington they to had the same findings as Wyoming also there was additional findings which corresponded with the smell of gas and my tank going empty after filling and trying to fill tank because was showing low fuel warning. Pictures were taken of the gas tank which had expanded as well as other pictures of the findings. I was told in Wyoming and Auburn that the code and findings are consistent with the Hyundai campaign

ELECTRICAL SYSTEM

The HVAC blower motor and related electrical components (including the fuse box, wiring harness, or control module) have malfunctioned. The system either fails to operate entirely or works only on low, with unpredictable surging airflow. These components are still installed in the vehicle and available for inspection upon request. For the past five days, my family has been driving without a functioning air conditioner in extreme Oklahoma summer heat. This is not only uncomfortable but unsafe, especially for my young child who regularly rides in the vehicle. In addition, without reliable airflow, we are unable to defog the windshield in humid conditions, which significantly reduces visibility and increases the risk of a crash. The inability to regulate cabin temperature and airflow poses a serious safety hazard. Yes, the issue has been observed by the dealership during service visits. However, Hyundai has denied goodwill repair assistance and has not formally acknowledged the defect, despite Technical Service Bulletins and numerous similar reports from other owners. Yes, the vehicle has been inspected by an authorized Hyundai dealership as part of a multi-point inspection. No warning lamps or dashboard messages appeared. However, symptoms began nearly a month ago and have persisted, including intermittent blower operation, limited airflow regardless of settings, and occasional surging. While I have not personally noticed a burning smell, I’ve found numerous reports from other 2020–2021 Sonata owners describing complete blower failure and smoke smells, often tied to fuse box or electrical issues.

FUEL/PROPULSION SYSTEM

Something went wrong in the fuel tank that caused it to become so pressurized that the tank expanded up and out so far that it pushed the exhaust pipe down and my back seat of out place. The only issue I had was the car was accelerating slower than usual but it wasn’t even enough of a difference for someone who didn’t drive it every day to be able to tell. It did this for two days then the check engine light came on and it just read “powertrain”. Began slow acceleration on 06.08.2025. Check engine light came on the night of 06.09.2025. I took it to the dealership 06.10.2025. I immediately took it into the dealership and they told me the car could have exploded. There was a previous recall for the fuel pump that I had replaced at the dealership. After seeing my car, they said their techs and the techs at HMA have never seen one this bad and that maybe after replacing the recall part the system update failed in my vehicle and the issue was never actually resolved.

FUEL/PROPULSION SYSTEM

I received a notice in the mail my car needed a software update. I went to the dealership to have the update performed. They informed me there was a service campaign for an expanding fuel tank due to pressure. They were unable to return my car to me at that time stating they were awaiting direction from Hyundai Motor of America for the fix. The fuel tank expanded so much it bent the body of of the car underneath the backseat. It also broke the support straps. The dealership stated it was a known issue with a vent valve. Causing the fuel tank to swell so much it damaged the body. They have had my vehicle for 9 weeks with no direction as to what to next.

FUEL/PROPULSION SYSTEM

It was about 100 degrees outside yesterday, and while trying to pass a car, I look in my rearview mirror and notice there is fuel shooting out from my fill hose under my gas flap. I lost over 3 gallons of fuel on the road. This happened my whole 60 mile trip. This has happened to me before, but the temperature was around 76 degrees and it does not happen in cold weather. I have a feeling my fuel tank is expanding because when I took out my back seat where my fuel tank is located, the body of the car is all buckled up to the point where I can't get my backseat to latch down anymore. My car is available anytime for inspection upon request. I have not taken it to a dealer to get it looked at, there has not been a police report filed. And there were no warning lights or indicators other than a popping sound coming from my backseat area before the problem occurred. There are no warning lights or indicators after the problem either. I feel like I'm driving a bomb because my fuel tank could blow up at any time. This problem can be reproduced anytime by filling the tank and driving it in 90 degree weather.

FUEL/PROPULSION SYSTEM

I experienced an issue where the gas tank in my 2020 Sonata began to swell and emit loud popping noises while the vehicle was parked. I took it to the dealership, and Hyundai corporate eventually acknowledged the issue and agreed to buy out my loan. However, no official recall has been issued for this model year. This problem has had a major impact on my life. I lost my job due to not having transportation for over two months, and the stress of not knowing whether my vehicle was safe made it even worse. I had to upgrade my insurance for a loaner I never received, take financial hits, and go into deeper credit trouble—all while also recovering from a serious injury from a previous car accident. I now have to start over with a new loan while my credit is already damaged. I’m submitting this report not just for myself, but to ensure that other 2020 Sonata owners are protected and made aware of this issue. I believe this is a serious defect that warrants official investigation.

BACK OVER PREVENTION

The contact owns a 2020 Hyundai Sonata. The contact stated that after shifting into reverse(R), the back over prevention camera screen temporarily displayed an image before the screen went black. The contact stated that the failure had become a recurring failure, but recently became a constant failure. The contact had not taken the vehicle to a dealer or independent mechanic to be diagnosed or repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 64,000.

WHEELS

So I was driving down the highway and I went to pass a car, (I never get close when passing) I was probably at least a quarter mile away from the car I was passing. I have every safety feature turned off, as I have, since buying the car almost 2 years ago. All of a sudden, I’m not sure if my sensor was off or what, but I’m assuming it thought I was too close to that car and it just started swerving all over the highway. I went left/right 4 times before I was finally able to regain control, I couldn’t couter-act the swerves, nor could I hold my steering wheel straight to stop them. Luckily there were very few people on the highway as it was early in the morning. Had the time of day been different, I probably wouldn’t be here today, and some others probably wouldn’t be either, at least lots of injuries I’m sure. It hasn’t been confirmed, i don’t even know how to do that honestly, I was the only one in the car. I didn’t call anyone/say anything until right now because I was already running late for work, I was shaken up but I just called my parents and they said to look up recalls/file a report, which it seems like this is how I do it? There were no warning signs, nothing, I was driving for already about 30 minutes and everything was fine, never had any issue like this ever before. Like I said I’ve had this car for almost 2 years and she has been an absolute dream, aside from this mishap. But now I am very terrified to drive it, i don’t know what happened honestly, I don’t know what could have caused it, but this is why I hate smart cars. My safety was put at risk by what I assume was a safety feature malfunction of some kind.

ELECTRICAL SYSTEM

So I was driving down the highway and I went to pass a car, (I never get close when passing) I was probably at least a quarter mile away from the car I was passing. I have every safety feature turned off, as I have, since buying the car almost 2 years ago. All of a sudden, I’m not sure if my sensor was off or what, but I’m assuming it thought I was too close to that car and it just started swerving all over the highway. I went left/right 4 times before I was finally able to regain control, I couldn’t couter-act the swerves, nor could I hold my steering wheel straight to stop them. Luckily there were very few people on the highway as it was early in the morning. Had the time of day been different, I probably wouldn’t be here today, and some others probably wouldn’t be either, at least lots of injuries I’m sure. It hasn’t been confirmed, i don’t even know how to do that honestly, I was the only one in the car. I didn’t call anyone/say anything until right now because I was already running late for work, I was shaken up but I just called my parents and they said to look up recalls/file a report, which it seems like this is how I do it? There were no warning signs, nothing, I was driving for already about 30 minutes and everything was fine, never had any issue like this ever before. Like I said I’ve had this car for almost 2 years and she has been an absolute dream, aside from this mishap. But now I am very terrified to drive it, i don’t know what happened honestly, I don’t know what could have caused it, but this is why I hate smart cars. My safety was put at risk by what I assume was a safety feature malfunction of some kind.

STEERING

So I was driving down the highway and I went to pass a car, (I never get close when passing) I was probably at least a quarter mile away from the car I was passing. I have every safety feature turned off, as I have, since buying the car almost 2 years ago. All of a sudden, I’m not sure if my sensor was off or what, but I’m assuming it thought I was too close to that car and it just started swerving all over the highway. I went left/right 4 times before I was finally able to regain control, I couldn’t couter-act the swerves, nor could I hold my steering wheel straight to stop them. Luckily there were very few people on the highway as it was early in the morning. Had the time of day been different, I probably wouldn’t be here today, and some others probably wouldn’t be either, at least lots of injuries I’m sure. It hasn’t been confirmed, i don’t even know how to do that honestly, I was the only one in the car. I didn’t call anyone/say anything until right now because I was already running late for work, I was shaken up but I just called my parents and they said to look up recalls/file a report, which it seems like this is how I do it? There were no warning signs, nothing, I was driving for already about 30 minutes and everything was fine, never had any issue like this ever before. Like I said I’ve had this car for almost 2 years and she has been an absolute dream, aside from this mishap. But now I am very terrified to drive it, i don’t know what happened honestly, I don’t know what could have caused it, but this is why I hate smart cars. My safety was put at risk by what I assume was a safety feature malfunction of some kind.

FORWARD COLLISION AVOIDANCE: WARNINGS

My 2020 Hyundai Sonata has a recurring defect in its engine or transmission, causing sudden deceleration to ~10 mph without warning, often on major highways, with warning lights (check engine, ESC, traction control, etc.) flashing seconds before the car decelerates. This forces me to swerve off busy roads, endangering me, my passengers, and other drivers. Near-misses with traffic pose an extreme safety risk, causing significant emotional distress. The car, at a Hyundai dealer since April 21, 2025, is available for NHTSA inspection. The issue began in January 2021, five months after purchase, with all the warning lights appearing during incidents along with rapid deceleration. The Hyundai dealer confirmed the problem in seven repair attempts (January 2021, December 2021, January 2022, November 2024, February 2025, and twice in April 2025) but never properly diagnosed or fixed it, citing no consistent diagnostic codes. Only the dealer assessed it; no inspections by Hyundai’s manufacturer, police, or insurance occurred. In November 2024, the defect recurred immediately after pickup, despite false assurances it was fixed. In February 2025, the dealer kept the car over a month with minimal communication, yet it failed again. I picked up the car on April 4, 2025, but it broke down on April 6, less than 55 hours later. I returned it April 7 and picked it up April 17, and it failed again on April 21, 2025 with the vehicle remaining at the dealer since. The dealer and Hyundai offer no solution and this dangerous issue keeps recurring. Similar NHTSA complaints suggest a broader issue. Rapid recurrences—hours after April 4 and four days after April 17—prove the car is unsafe and assurances of repairs are untrustworthy. I no longer trust the Sonata or Hyundai’s repairs, as the defect persists.

POWER TRAIN

My 2020 Hyundai Sonata has a recurring defect in its engine or transmission, causing sudden deceleration to ~10 mph without warning, often on major highways, with warning lights (check engine, ESC, traction control, etc.) flashing seconds before the car decelerates. This forces me to swerve off busy roads, endangering me, my passengers, and other drivers. Near-misses with traffic pose an extreme safety risk, causing significant emotional distress. The car, at a Hyundai dealer since April 21, 2025, is available for NHTSA inspection. The issue began in January 2021, five months after purchase, with all the warning lights appearing during incidents along with rapid deceleration. The Hyundai dealer confirmed the problem in seven repair attempts (January 2021, December 2021, January 2022, November 2024, February 2025, and twice in April 2025) but never properly diagnosed or fixed it, citing no consistent diagnostic codes. Only the dealer assessed it; no inspections by Hyundai’s manufacturer, police, or insurance occurred. In November 2024, the defect recurred immediately after pickup, despite false assurances it was fixed. In February 2025, the dealer kept the car over a month with minimal communication, yet it failed again. I picked up the car on April 4, 2025, but it broke down on April 6, less than 55 hours later. I returned it April 7 and picked it up April 17, and it failed again on April 21, 2025 with the vehicle remaining at the dealer since. The dealer and Hyundai offer no solution and this dangerous issue keeps recurring. Similar NHTSA complaints suggest a broader issue. Rapid recurrences—hours after April 4 and four days after April 17—prove the car is unsafe and assurances of repairs are untrustworthy. I no longer trust the Sonata or Hyundai’s repairs, as the defect persists.

ELECTRICAL SYSTEM

My 2020 Hyundai Sonata has a recurring defect in its engine or transmission, causing sudden deceleration to ~10 mph without warning, often on major highways, with warning lights (check engine, ESC, traction control, etc.) flashing seconds before the car decelerates. This forces me to swerve off busy roads, endangering me, my passengers, and other drivers. Near-misses with traffic pose an extreme safety risk, causing significant emotional distress. The car, at a Hyundai dealer since April 21, 2025, is available for NHTSA inspection. The issue began in January 2021, five months after purchase, with all the warning lights appearing during incidents along with rapid deceleration. The Hyundai dealer confirmed the problem in seven repair attempts (January 2021, December 2021, January 2022, November 2024, February 2025, and twice in April 2025) but never properly diagnosed or fixed it, citing no consistent diagnostic codes. Only the dealer assessed it; no inspections by Hyundai’s manufacturer, police, or insurance occurred. In November 2024, the defect recurred immediately after pickup, despite false assurances it was fixed. In February 2025, the dealer kept the car over a month with minimal communication, yet it failed again. I picked up the car on April 4, 2025, but it broke down on April 6, less than 55 hours later. I returned it April 7 and picked it up April 17, and it failed again on April 21, 2025 with the vehicle remaining at the dealer since. The dealer and Hyundai offer no solution and this dangerous issue keeps recurring. Similar NHTSA complaints suggest a broader issue. Rapid recurrences—hours after April 4 and four days after April 17—prove the car is unsafe and assurances of repairs are untrustworthy. I no longer trust the Sonata or Hyundai’s repairs, as the defect persists.

SEATS

My wife and son experienced a terrible situation on the way home from training. They had to stop at the nearest gas station due to the vehicle showing extremely low gas in the tank during a short drive home. The fuel gauge initially showed about half a tank but drastically dropped on the way home. They stopped at a gas station to add fuel but during the process, fuel starting spewing out of the tank. The vehicle was scheduled to be dropped off at a later date for an open recall (service campaign 9B1). I called the dealership and told them I needed to get the vehicle in right away due to the incident. After bringing the vehicle to hyundai, they told me that the fuel tank exploded causing the tank to swell all the way around. Because the tank is located under the rear seat, we constantly heard air coming in due to the rear seat not seating properly. The check engine also was on and we smelled fuel while driving the vehicle. Hyundai representatives has been avoiding my calls to the point where I had to go in person for an update. Apparently, a district manager had to come inspect the vehicle to advise the dealership how to write up the request to send to corporate.

FUEL/PROPULSION SYSTEM

My wife and son experienced a terrible situation on the way home from training. They had to stop at the nearest gas station due to the vehicle showing extremely low gas in the tank during a short drive home. The fuel gauge initially showed about half a tank but drastically dropped on the way home. They stopped at a gas station to add fuel but during the process, fuel starting spewing out of the tank. The vehicle was scheduled to be dropped off at a later date for an open recall (service campaign 9B1). I called the dealership and told them I needed to get the vehicle in right away due to the incident. After bringing the vehicle to hyundai, they told me that the fuel tank exploded causing the tank to swell all the way around. Because the tank is located under the rear seat, we constantly heard air coming in due to the rear seat not seating properly. The check engine also was on and we smelled fuel while driving the vehicle. Hyundai representatives has been avoiding my calls to the point where I had to go in person for an update. Apparently, a district manager had to come inspect the vehicle to advise the dealership how to write up the request to send to corporate.

SEATS

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.

FORWARD COLLISION AVOIDANCE: WARNINGS

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.

POWER TRAIN

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.

ELECTRICAL SYSTEM

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.

POWER TRAIN

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.

FORWARD COLLISION AVOIDANCE: WARNINGS

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.

ELECTRICAL SYSTEM

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.

VEHICLE SPEED CONTROL

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

FUEL/PROPULSION SYSTEM

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

POWER TRAIN

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

STRUCTURE:BODY

Service Campaign 9B1 That my gas tank has explanded/exploded due to the issue noted in the subject line. As you can see the whole bottom of the backseats have been raised up imcluding the part that connects to the gas tank itself. My car is immobilized and not drivable during this time. What is the next step to take?

FUEL/PROPULSION SYSTEM

Service Campaign 9B1 That my gas tank has explanded/exploded due to the issue noted in the subject line. As you can see the whole bottom of the backseats have been raised up imcluding the part that connects to the gas tank itself. My car is immobilized and not drivable during this time. What is the next step to take?

FUEL/PROPULSION SYSTEM

Fuel system expanded back seat

FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP

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.

STRUCTURE:BODY

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.

FUEL/PROPULSION SYSTEM

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.

UNKNOWN OR OTHER

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.

ELECTRICAL SYSTEM

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.

ENGINE

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.