2020 Hyundai Sonata

While stopping at a major highway intersection on [XXX] for a red light vehicle stalls and will not start back up while everyone else continues at a 55 mph mile an hour passing me on each side! This happened more than 6 times . While you’re stuck in intersection,you have to keep trying to start the car eventually it will start . Apparently it is EGR valve and is a very common problem. IT IS NOTED IN THE common problem for this year making model and the repair cost is in the range of $1600 even the dealership said it is a very common problem. They have been experiencing it. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2020 Hyundai Sonata. The contact stated that while the vehicle was parked, the vehicle failed to start as intended. The contact stated that several unknown warning lights were illuminated. The contact stated that the vehicle eventually started and drove normally. The vehicle was then taken to an independent mechanic, where it was diagnosed and determined that the starter needed to be replaced. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was 27,000.

Wiring harness under fuse box is not making a consistent connection and is causing the blower amp to overheat and disconnect. When this happen, cabin air doesn’t blow and the front and rear defrost stops working. The only way to make the blower engage is by removing the fuse box cover and tapping the 30 amp fuse things. I’ve taken my car to the dealership for this specific problem 5 separate times, and it was supposed to be corrected. Due to this poor connection, I am now about $1200 into repairs / replacing parts that aren’t the root cause. I am not taking my car back to the dealership for a 6th time to have it “fixed” but the service guy looked me in the face and said “you should trade it. We see this issue all the time in sonatas and elantras. It won’t be fixed”. I’ve replaced the blower motor, had the Freon charged, this is one of the vehicles with the exploding gas tank, and I’ve already paid to replace gaskets.

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

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.

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.

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.

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.

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.