2025 Hyundai Ioniq 5

On January 1st, while driving on a highway, my vehicle experienced a sudden electrical/battery system failure. Warning messages appeared and the vehicle abruptly reduced power and speed, creating an extremely dangerous situation. This occurred in severe winter conditions, with snow on the road and temperatures below 27°F. The vehicle was unable to maintain safe highway speed, putting me and other drivers at serious risk of an accident. Hyundai Roadside Assistance failed at the time of the incident, as the mobile app did not work. I was forced to contact my personal insurance for towing and remained stranded at the location until approximately 7:00 AM. Due to this failure, I incurred over $400 in Uber transportation expenses. The incident was unexpected, occurred without prior warning, and represents a critical safety concern, especially given the vehicle’s low mileage. A sudden loss of power in highway and winter conditions is life-threatening and should be investigated as a potential safety defect.

I am reporting a serious safety defect involving my 2025 Hyundai Ioniq 5 (lease vehicle, brand new). While driving on a highway in Massachusetts during snowy conditions, the vehicle suddenly displayed a critical warning message “Stop and Check Power Supply” and lost power, forcing us to stop on the highway. There were two children in the vehicle, and the situation was life-threatening due to traffic speed, weather conditions, and lack of a safe shoulder. The vehicle is new and under lease, and this type of failure is unacceptable and extremely dangerous. The car had to be towed to Hyundai of Braintree, MA. This is a serious safety failure, not a comfort or convenience issue. I am concerned this defect could result in serious injury or death if it happens again, either to my family or to others. I am requesting a formal investigation into this defect.

I was driving on the freeway in the left lane when suddenly a bunch of error lights popped up on the dash and the car threw itself into neutral. When I tried to give the car acceleration it wouldn’t go which is when I realized the car was in neutral. When I tried to go into drive it did not go so I turned the hazard lights on. Turned off the car, turned it back on and then again all the error lights popped up. I went into drive and when I drove a loud bang noise happened in the rear and after a few feet the car went into neutral. I repeated the process trying to merge from the left lane into the middle where finally the car would not even go into drive anymore. I then called 911 and had them tow the car off the freeway while I waited inside. Car had 3400 miles, was only a few months old (brand new) and I had 60% battery left with almost 200 miles of electric range left. It was a sunny day with no moisture recently.

With no warning lamps or lights, heard a pop, car stopped generating power, there was no place to pull over so we put on our hazards and kept driving. Car warning light on batter and it was telling us to stop driving as soon as possible, cars were honking and driving around us. We called AAA and they towed to the dealership we bought the car (it's a new car 8,000 miles). The ICCU failed, they replaced it. Reddit Ioniq5 owners report this problem is more frequent than other electric cars and that Hyundai has a recurring issue with this part.

On the afternoon of Saturday, December 12th 2025 I was preparing my car for a trip an hour north and back to drop my daughter off with her grandmother. I was charging my car with my Level 2 charger and preheating my car. Upon leaving for the trip, within a half mile I heard a loud popping sound coming from the rear of the vehicle and immediately had a warning on the vehicle stating "Stop Vehicle and Check Power Supply". The vehicle soon started to lose drive power, and I had to perform a U-turn and then parked at the nearby Quaill Volunteer Fire Department to perform a basic safety check. Knowing that I probably had the Hyundai Ioniq 5 ICCU issue, I knew that my car would soon have no power so I waited for an opportune time to leave the fire station to coast back to my house. After arriving home, I contacted Hyundai Roadside Assistance and my car was soon towed away. I was extremely fortunate to be so close to home when this happened - from what I know of the issue, had we been stranded on the highway with this issue we would likely not have been able to use the HVAC systems in the vehicle for long. At this point, the issue has been diagnosed at the dealership as an ICCU issue which is covered by warranty. I have not been told to modify anything about my charging amperage, and there has been no admission that the ICCU part itself is faulty (though I believe it must be - my vehicle has less than 8,000 miles and the previous model years of Ioniq 5 all had ICCU recalls already.)

I was driving with my family on 12/26/2025 and heard a very loud "pop" and then received a warning of "stop vehicle and check power supply." The car went into turtle mode and then stopped working entirely. It was a terrifying situation because there was no place to pull over immediately and the car was not operating. We were stranded as a storm was approaching, could not get a tow, etc. On 12/30/2025 the dealer told me I needed a new ICCU and fuse.

I leased a 2025 Hyundai Ioniq 5 (VIN: [XXX] ) on September 16, 2025 from Route 1 Hyundai in Monmouth Junction, New Jersey. Since I bought the vehicle, I have had to return it to the dealership a total of one time. My vehicle has been out of service for repairs since November 19, 2025 for a total of 35 calendar days. The current mileage on my vehicle is 3,026 miles. My vehicle has been in service at Route 1 Hyundai on the following days for repair of the following defects: Days: 11/19/2025 - present Defects: DTC P0AA700 Hybrid Battery Voltage Isolation Sensor Circuit fault This is a critical safety mechanism, and when this fault occurs, the high-voltage system will often shut down to prevent electrocution or further damage. DTC P1AA700 DTC P1AA700 on a Hyundai Ioniq indicates a serious issue with the high-voltage (HV) Battery System Assembly (BSA). I am having the following problems with my vehicle at this time: Unable to charge battery past ~30% INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)