2023 Hyundai Sonata Hybrid

UNKNOWN- While driving on highway, from 70 mph speed the car suddenly lost acceleration and speed dropped. No response to accelerator. Even with pushing the accelerator high, car will go in high RPM and speed will barely reach 40 mph. I was lucky that there was no other vehicle behind me, especially heavy automobile like semi truck as it would have crashed in me from behind due to sudden propulsion loss. The car started working fine next day. I took it to dealer and they couldn't find any error code but said it could be 12V battery BMS software update and they updated it. They mentioned that this is NOT a safety issue which is mind-blowing and concerning as this is a MAJOR safety hazard. I would request you to investigate this further and if this is a software issue then please direct Hyundai to update this with all vehicles and cover the cost for those who have had to pay for it.

On 11/28/25 at approximately 6:30 pm, I was driving on a Highway 17 going about 60 mph when my car's engine completely shut down. a "Hybrid System Failure" warning flashed and my car was no longer drivable. The car was towed to the dealership. In mid October 2025, my car stopped running with the same "Hybrid System Failure" warning, but it happened in my driveway. The car was towed to the dealership and supposedly repaired.

The vehicle went in for repair at the dealership early July for a check engine light and DTC error code. It was revving high after being driven for more than 20 min or so and wouldn’t get to above 60 mph. Jerky, dangerous acceleration and deceleration seemingly out of nowhere. The dealership replaced the fuel pump which is what they said was causing the error. Today on August 10th, check engine light popped up again with a DTC error code. Weird acceleration and deceleration and general jerkiness when driving. Scheduled service appointment for next week.

The contact owns a 2023 Hyundai Sonata. The contact stated that while driving 75 MPH, the vehicle briefly lost motive power before downshifting to a lower gear. In addition, the engine revved independently. The contact was able to pull over to the side of the road and turned off the vehicle. The contact was able to restart the vehicle; however, the vehicle failed to exceed 60 MPH. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The failure persisted, and the vehicle was no longer being driven. The contact parked the vehicle at the residence. The contact started the vehicle and the check engine warning light illuminated. The manufacturer was not notified of the failure. The failure mileage was approximately 34,000.

I BOUGHT THIS CAR BRAND NEW IN NOVEMBER 2023, BY FEBRUARY, THE CAR STARTED STALLING ON THE STREETS/HYWAY. ALL DASH LIGHTS WOULD COME ON, THE VEHICLE WOULD STALL AND IS NO LONGER ABLE TO RESTART. THIS HAPPENED 4 TIME IN 2024. WHEN I TOW IT TO THE DEALER, THEY ALWAYS COME BACK WITH THE SAME ANSWER. ''THE AC MOTOR POWER CABLE HAS BEEN DISCONNECTING LEADING TO LOSE OF POWER''. THEY HAVE REPLACED IT 4X BUT THE SAME PROBLEM PERSIST. IT'S VERY SCARY ESPECIALLY WHN AM DRIVING IN A BUSY ROAD OR WHEN AM DRIVING AT NIGHT IN THE MIDDLE OF WINTER. AM NOT SURE HOW TO MOVE FROM HERE. THANKS.