2025 Hyundai Ioniq 5

As I was driving on a very busy city street I heard a loud pop and then got a warning to check electrical systems. Luckily I was able to get the car to a Walmart parking lot and arrange for the car to be towed to a dealer 90 miles away. The dealer contacted me and informed me the ICCU unit and high voltage fuse would have to be replaced and no time frame for parts availability to be determined. This is apparently a recurring problem with the ICCU component of Hyundai electric vehicles that could potentially leave a driver stranded in the middle of nowhere in the middle of winter.

Vehicle is approximately 8 months old, has 9390 miles on odometer. While on a road trip, we stopped to charge the vehicle at a DC fast charging site. After about 10 minutes of charging, there was a loud pop sound and the vehicle stopped charging. Attempting to unplug and replug the charger into the car gave nothing but an error. Contacting support, was told that the vehicle has an air flap problem. That is not the problem. The charge controller system (ICCU) failed during charging, leaving the vehicle without power to charge the 12V battery system, and only enough driving power to limp 1 mile to a hotel. Vehicle required towing 400 miles to get to home dealership for repairs. Hyundai reps have stated that this 2025 vehicle is not part of the ICCU failures recall, but it is obviously exhibiting the same problems. I no longer have confidence this car can be driven any significant distance from home, which ruins the functional value of the vehicle.

On [XXX] my Ioniq 5 stopped operating. It was totally dead. Could not be jumped. Car was towed to the dealership where they had replace the battery, ICCU and fuse. It took about two weeks for this to occur. The car had 3500 miles on it when this happened. Prior to the car not stopping an electrical warning light came on and the car speed was limited to 25 miles an hour but totally ran out of juice in about 10 minutes. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

At power-on, the car's diagnostics alerted with DTC code P1A9096, indicating a failure of the Low voltage DC-DC converter / ICCU. Vehicle was parked at home at the time, but there is the distinct possibility of being stranted at an outstation or outside cellular / tow coverage. Vehicle was towed to an authorized service center for warranty repairs (the car is ~5 months from date of purchase)

I had driven a few miles to a store and was inside for about 10 minutes. I went out to the parking lot and started the car by pressing the button. Within the first couple of seconds after starting, there was a loud pop sound, followed by alerts on the dashboard. Checking the onboard diagnostics, I saw an alert that the charging system had a fault. Using the MyHyundai app, I saw a diagnostic code of P1A9096. I was able to drive home (albeit limited to about 40 MPH on a road with a 50 MPH speed limit and traffic that drives faster than that) and park. Testing it later that night, I was able to start it, but soon after, there was a loud beeping sound and bright red alert on the dash warning me that I should "Stop vehicle and check power supply." The next morning, when trying to get it on the flatbed tow truck, the vehicle started, but when I tried to adjust the seat for the tow truck driver, it went entirely dead. The driver jumpstarted it, but it was difficult to get the car into gear to move it on the flatbed. Around this time, I noticed that the phone was showing two new diagnostic entries, both with code P056216. We eventually got it into gear and onto the truck, and then delivered to the dealer, where it is currently awaiting diagnostics. There was no obvious safety issue while I was driving, though I worry now that if I had tried to use the 12V system while I was driving, then the entire system might have failed while in motion.

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.

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.)