2025 HYUNDAI IONIQ 5 Complaints

ICCU failure while driving. Car unable to charge 12V battery rendering the vehicle un-driveable.

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)

Was driving shortly after starting the car and heard loud pop. Immediately received notification that I there was a problem with the electrical system. Received DAT code P1A9096. Car is undrivable. Had to pull over to side of the road and call for tow.

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)

With 3100 mileage, the car experienced an electric systems failure which resulted in the car no longer being functional. Towed to dealership where they officially stated a failure of the ICCU. Will have to wait days, possibly weeks for replacement part, but no guarantee this won't happen again.

Leaving our home garage a loud popping sound was heard and dashboard warning signals came on indicating battery failure. Dealer confirmed the ICCU failed.

The electrical system failed while driving and I could not accelerate more than 25 mph with two children in the car. The error message said stop car and evaluate power supply. My safety and my children's safety were put at risk as I was driving on a highway and could no longer accelerate above 25mph. Yes the problem was reproduced. Manufacturer is inspecting now. There was a warning light that appeared only while driving and when the initial probably began. The dealer told me this is ICCU failure, this is happening frequently, there is no timetable to get a replacement.

I was driving on the CA 405 SB, Long Beach, at about 6 PM 9/19/25. All of a sudden this loud screeching noise started. It was so loud that I pulled off on the left shoulder instead of driving to the first exit. I assumed I was going to find something wrapped around an axle or wheel or dragging from the ground. There was nothing hanging from the car, so I got back onto the freeway and parking the car ASAP did a more thorough inspection of the car. I got on my hands and knees looked with a the flashlight And saw nothing. I got online and found Hyundai TSB 25-01-056H explaining that IONIQ 5 built between 12.03.24 - 3.25.25 are missing a wave washer that can cause the MGDU housing to make noise. And the MGDU needs to be replaced. I should take it to a dealer to get it fixed. I left a message with the service dept at Kearny Mesa Hyundai, where I'd leased the car on June 2, 2025. I left a VM with the Service Dept requesting an appointment and the screeching noise is my car. I made a number of recordings of the noise so I could easily provide it later. The noise stopped when I got off the freeway and hadnt started again. When I took it in on 9.22.25. They said I would have to leave the car for at least two weeks before they could look at it. They wouldn't provide a loaner because my car was built in APR/2025 after 3.25.25. The SA suggested I try another dealer for faster service. I took it to Pedder Hyundai on 9.24.25. They kept it all day and "verified the complaint." My window was not fully up. I told them that this is absurd. I was told the dealer needs to verify the noise to get it fixed under warranty. On 10.19 the noise started I made more recordings & drove it straight to the dealer. They couldnt get someone to go for a ride and had to get appnt and bring it back. I took it in on 10.21 while driving there, and the noise returned. I called the Serv Rep. He heard it clearly How can I send you the recordings of the noise?

The Lane Keeping Assist works well and is very useful. Unfortunately it is combined with the infrared eye monitor system, which is very flaky and does not work well with prescription glasses when sunlight comes in from the front or side. It provides many false warnings, but cannot be turned off without losing the Lane Keeping Assist. If I drive without my glasses, it works fine, but it seems counter-productive to make me lose a good functioning system by tying it to a flaky not-useful monitor.

Car failed while I was parked in the SFO airport cell phone lot. It was night and very cold. There was no warning of a problem. Car had to be towed to Hyundai of San Bruno. It is still there. DTC: P1A9096. Hyundai dealer confirmed ICCU failure. Not repaired in a timely manner to non availability of part.