2020 Hyundai Sonata: engine stalls while driving

Filed Oct 15, 2026 · Brakes, Engine · KY

Vehicle experienced intermittent, severe powertrain defect resulting in a critical safety hazard. Between 30K and 36K miles, the vehicle underwent 3 violent highway deceleration episodes. During these events, the engine began shaking, escalating to violent shaking; with deceleration and coming to a stop, it would shake, then sputter as if it would die. Coming to a complete stop, a total stall was prevented only by the ECM forcing a limp mode lock at 1200 RPMs. When Auto Hold was engaged at this point and my foot was removed from the brake pedal, the mechanical surge caused the vehicle to unexpectedly lurch forward, fighting against and nearly overriding the factory Auto Hold braking safety feature before finally holding. Luckily, no pedestrian was walking in front of my car when this occurred. No check engine light (CEL) or dashboard warning ever illuminated. This safety compromise is directly tied to an ineffective or adjacent remedy involving Service Campaign 9B1 (Opcode 40D219R0) and Safety Recall 286. Under this Opcode, a factory software flash deleted the standard OBD-II trouble code P0451and substituted it with a manufacturer-specific shadow code P14EE00. This software manipulation suppressed universal emission/pressure sensor faults, masking a volatile physical defect within the high pressure fuel delivery and ignition systems. Dealer diagnostics on a running, compromised engine flagged an improper fuel injector pulse and subsequently a failing Cylinder 3 ignition coil. All four injectors were replaced but only one coil, leaving 3 non-updated , factory defective coils in the engine. The vehicle remains an ongoing highway stalling and brake-override hazard due to an incomplete field remedy of a recall-adjacent system. I've filed a Hyundai Complaint with assigned case number 43394228 regarding Safety Recall 286. (Two episodes of the attempted Auto Hold override occurred - first 09/09/2026 and second 09/29/2026.)

Filed Aug 18, 2026 · Electrical · NJ

The AC/heating blower motor circuit on my 2020 Hyundai Sonata failed intermittently due to extreme electrical resistance overheating and melting the terminal pins inside the engine fuse box. I took it to the dealership and they inspected it said it was out of warranty but it needed part number 18980-09910-FFF and wiring kit 91300L1000-FF to repair at a cost of 780.00 including parts, tax, and labor. This matches the severe design defect acknowledged in Hyundai TSB #25-EE-002H or alternative TSB-24-EEOO-1H. I filed case number 43138757 with Hyundai corporate. For now this just affects my air conditioning. However, the root failure is a known design defect that presents a severe vehicle fire hazard and potential loss of windshield defrosting capability, lights, etc. if the whole electrical system should fail. As you should know the engine bay fuse box (which currently has melted parts) is the "brain" for the car's electrical distribution. It doesn't just power my AC fan; it holds the fuses and relays for the cars fuel pump, engine control module (ECM), headlights, and electronic power steering. If left unfixed and over time as the plastic melts, copper wires will cross and touch each other, causing a massive short circuit. My engine could suddenly cut out and stall while I am traveling at 70 mph on the highway, instantly killing my power steering and power brakes and putting me in extreme danger. Again not to mention the fire hazard this situation is likely to cause. This should be addressed via a mandatory safety recall, so that I don’t have to pay for a known engineering design defect and in case the TBS bulletin fails or further unknown damage has already occurred.

Filed Jun 14, 2026 · Engine · OH

My 2020 Hyundai Sonata 2.5L is experiencing excessive engine oil consumption. At approximately 88,063 miles, Great Lakes Hyundai documented that the engine oil level was 1.30 quarts below full after an oil-consumption check. The dealer topped off the oil, submitted photos and a prior-authorization/goodwill request to Hyundai, and Hyundai declined assistance. The dealer recommended combustion chamber cleaning with an estimate of $979.76. I am concerned that this excessive oil consumption could lead to sudden engine damage, loss of power, stalling, or engine failure if the oil level drops between checks. The vehicle is only a 2020 model year, and this level of oil consumption appears abnormal. I am also concerned about possible emissions/catalytic converter damage from oil burning.

Filed May 8, 2026 · Engine, Fuel system · 80,000 miles · MD

The contact owns a 2020 Hyundai Sonata. The contact stated that the fuel failed to go into the tank. The seat failed to move. The engine light illuminated. The vehicle stalled. While driving, the fuel gauge went from full to empty. The contact received the federal safety agency Campaign Number: 25V796000 (Fuel System, Gasoline) after the failure. The vehicle was towed to the local where it was diagnosed that the fuel tank had expanded. The vehicle was repaired approximately eight months later. The contact called another local dealer. Ourisman Hyundai Bowie, 2404 Crain Hwy A, Bowie, MD 20716, who was unable to schedule an appointment. The manufacturer instructed the dealer to keep the vehicle due to it being a fire risk. The manufacturer was contacted regarding a buyback. The failure mileage was approximately 80,000.

Filed Apr 22, 2026 · Fuel system · FL

the federal safety agency Complaint Statement Subject: Stop‑Drive Recall – Vehicle Held Since March 5, 2026 – No Remedy, No Transportation, Buyback Delayed I am filing a complaint regarding a stop‑drive safety recall that has left me without access to my vehicle since March 5, 2026, and the manufacturer has not provided a timely remedy, transportation assistance, or a completed buyback. My vehicle has been at the dealership since March 5 due to a manufacturer-issued stop‑drive recall. The dealership has confirmed they cannot legally release the vehicle because of the stop‑drive order. The vehicle is not repairable at this time, and the manufacturer initiated a buyback process. However, the manufacturer has been extremely slow to communicate or complete the buyback. Despite multiple attempts to contact them, I have not received a clear timeline, and the process has stalled. I have also not been provided with a loaner vehicle or consistent rental reimbursement, even though the stop‑drive order prevents me from using my car. Because of the delay, I am now facing financial hardship, including a past‑due car loan on a vehicle I cannot legally drive and cannot retrieve. I am effectively without transportation and without a remedy. I am requesting the federal safety agency’s assistance because the manufacturer has not met its obligations to provide a timely remedy or adequate support for a stop‑drive recall that has removed my vehicle from service for an extended period.

Filed Dec 30, 2025 · Electrical, Engine · FL · crash

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)

Filed Mar 11, 2025 · Fuel system · 77,524 miles · TX

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.

Filed Apr 11, 2021 · Engine · 1,389 miles · NY

On nov. 17 while driving app. 65 MPH on the highway the car suddenly shut itself off. All of the dashboard lights lit up & the car would not restart. After 10 min. Of trying to restart the car, the car started again, & all the lights on the car disappeared. The following day, while waiting in the turning lane at a red light, the car sputtered & turned off. All the lights on the dashboard lit up & the car wouldn't start I had the car towed on nov 18 202 to a hyundai dealership. The dealership reported that there was an internal short with the ABS module & the hydraulic module assembly was replaced. On, nov 24, I was driving the car & the car stalled all the warning lights went back on. I had the car towed the dealership where it stayed until december 11 the dealership stated that they could not find anything wrong with the car. I picked up the car on dec 11 & the car appeared to be working normally. However, on dec19, while stopped at a red light, the car began to shake back & forth at idle & the rpms started to go up despite my foot being on the brakes. The car behind me saw what was happening & helped me pull over to the side of the road. I had the car towed to the dealership yet again. The dealership stated that they were able to duplicate the issue on dec 23, 2020. However, no fix was done to the car. The dealership claimed that the car was in a 'relearn' process & it would need more time for the car to 'relearn' how to drive again. Everything seemed okay after the dec 23 incident until feb 8 2021 when I tried to stop while in traffic & the brakes would not work at all. I narrowly avoided getting into a major accident & once again brought the car to the dealership. The dealership found that the master cylinder assembly was internally defective & was not holding pressure and as a result the brakes were not working. The vehicle was returned to me on feb 11 2021.

Filed Sep 23, 2020 · Engine · 1,200 miles · FL

My car stalled and stuttered between 1000 and 1500 miles in traffic and couldn't get it into gear once started. It was the fuel rail sensor. Now at 6000 miles did same thing. If sits for bit works again. It also reset itself and I lost all preprogrammed information. The gas door also opens at times when unlock driver door. The dealership had it the first time for over 30 days and had to contact engineers to fix it.

Filed Jul 13, 2020 · Engine, Transmission · 1 miles · NJ

Vehicle abruptly stopped in a traffic signal without giving any indications what so ever. When tried to restart it stalled pretty badly causing excessive vibrations. This had just 1900 miles on it. Vehicle didn't have any mil or any visible information about the issue. It created a huge traffic pile up due to the peak hour in which this problem started. Few days ago there was issue with starting but it resolved after couple of minutes, this time the vehicle had to be towed to the dealership and I lost my days work and pay. Biggest concern is how abruptly it stopped in a busy street.

Filed Jul 8, 2020 · Engine, Transmission · 2,700 miles · IA

Vehicle rough idled & eventually shuddered to a stop. This happened four times while in gear and idling at appx 1000-1500 miles. Between 1500-2000 miles, vehicle shut down while driving appx 60mph on a county road. At appx 2700 miles, mpgs drastically impacted when vehicle suddenly stopped shifting gears properly while in motion at appx 70mph on the highway. Check engine light appeared with message regarding ecs issues. Vehicle still drives, it just seems to struggle with efficiency and shifting correctly.