2025 HYUNDAI IONIQ 5 Fuel/propulsion System Problems

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.

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.

The ICCU unit failed causing the car to first have low power, reducing the maximum vehicle speed to 25 MPH, then causing the 12V battery to lose charge making the car inopperable.

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.

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 leaving from a friends' house and got a "Check electric vehicle system" error and the car went into "limp" mode while on the road. I drove to a hotel parking lot and dropped off my family then proceeded the next day to drive the car to a local dealership for service and the car maxed out at 12 mph before crawling to 1 mph while going up a hill before I could find a place on the side of the road to stop. While awaiting a tow truck the car's electrical system fully "died" leaving me stranded on the side of the road without even hazard lights to warn surrounding traffic. The problem has not yet been evaluated by a dealership, manufacturer or any other agencies. Several warning lamps and messages appeared, including the "Check electric vehicle system" error message.

My car worked to get to an appointment on 22 Nov. It flashed an error 2 minutes into a 20 minute return trip, saying the cars propulsion failure was imminent. Vehicle would not turn back on after the 3 mile drive home. The ICCU failed. If this failed while driving, or while I was in a hot/cold location, my life and those around me would have been at risk. The dealer has been working with Hyundai America for a month to fix the vehicle, and so far has not been able to after trying 2x replacement parts.

On October 10, 2025, while driving the car, a turtle suddenly popped up in place of the speedometer. The car's power and speed was drastically reduced. There was a car behind me that started tailgating me and I could not go any faster than about 15 mph. I was able to make it home. Later that night, I tried to charge the car and it started to overheat. The ICCU recall need to be extended to 2025 models. Ours has been replaced, as well as the PCM and many other parts. Our car still sits at the Hyundai service center because they cannot figure out why the car won't charge.

Driving a loud bang was heard from the back of the car. Stopped to check, no obvious physical issue. A warning light came on, it was described as an issue with the air flap. Started driving again, it worked for a few 1000 feet. The car went into a limp mode while an arterial road, in the dark, slowing to not more than 20 mph on a 45 mph road putting driver and child passenger as well as other vehicles at risk. Had to limp until a driveway was found about 3/4 mile later. We got DTC P1A9096 code. The dealer confirm this was an ICCU issue and the related fuse was blown.

I was driving down the highway at about 65 mph. "Electrical failure" warning showed up and the abruptly began to lose power. We were able to pull over 2 lanes to the shoulder. The car then completely shut down after about 2 minutes. I was unable to have my hazards on and 2 young children in car seats were in my vehicle. I was on a really bad part of the road and had to move two young children into another car and barely had enough power to get over. The dealer told me I just had a bad battery and they replaced it and it was fine. I called Hyundai corporate and they said "they weren't aware of any issues with the cars ICCU" it wasn't until my husband called the dealer again and had to be extremely pushy with them that they saw it was an ICCU failure. They are replacing it now.

ICCU failure

I was driving to work on the morning of Nov. 12th, 2025 in East Greenwich RI. The car had been fully charged on my home Level 2 charger the night before. It was a chilly morning so I turned on the heated driver seat and steering wheel. Less than a mile from my house, and without any warning or prior issues, I heard a loud pop from underneath the vehicle. Immediately the car displayed an error on the dash reporting electrical system issues. The car still seemed driveable so I began to drive back home, noting that the car wouldn't exceed ~30 mph, but before I went very far at all the error changed to "Stop vehicle and check power supply." I pulled the car over on a side road and called for a tow to the nearest Hyundai service center in North Kingstown, RI. The next day the Hyundai service center reported that their diagnostics revealed that the ICCU had failed. I subsequently learned that they had been unable to drive the car even from their lot into the service bay - even with a jump charger the car wouldn't drive and they had to carry the scanner to the lot for the diagnosis. The Hyundai app reports 96% battery charge even now, which says that the 12V battery has been fully discharged, consistent with ICCU failure. The service center has not reported that the ICCU has been inspected by any other authorities other than them. The replacement part is due to arrive today, 11/15, and should be installed on Monday 11/17. This exact problem is apparently very common to Hyundai and Kia EVs, and was the subject of a recall for the 2022-24 IONIQ 5 model years.

ICCU failure randomly while driving. Left me stranded during a cold night until a tow truck could come. Dealer has confirmed ICCU failure and Hyundai is repairing under warranty.

Was driving for 12 miles, at a stop light. Light turns green, I accelerate, loud collision warning goes off and warning “battery overheated! Pull over safely and leave the vehicle”. Could not pull over safely because the car immediately ceased and locked up, car behind me nearly rear ended me and swerved to avoid. Is this another ICCU unit failure? Car towed to dealership (car has 2056 miles in it, it’s practically new) and been there for almost a month now with no repairs done and still diagnosing the problem. This car is unsafe.

On the first snowy day of the year, the car experienced an apparent ICCU failure. Loud pop followed by warning lights, reduced power and eventual complete shutdown of the car. Car has been towed to dealership for diagnosis and repair.

I heard a "pop" and then immediately saw "check electric vehicle system". The code I'm receiving in the app is P1A9096. The car was limited in driving speed, and I managed to get the car to the dealer before it stopped driving completely. I have about 8000 miles on this <1 year old car, and it seems like the ICCU has fried. Hyundai says this is under 1% of all cars, but from the internet it seems like this happens way more frequently. Reporting to the NHTSA so that there's record of this happening, given the frequency it seems to happen on the internet and the paucity of solutions (beyond putting in another faulty part) from Hyundai.

Traveling on Highway at 65 mph the vehicle suddenly lost speed and would not respond when my foot pressed on the acceleration pedal. I made it off the freeway to the exit. I turned the EV off and on and the car accelerated until I came to a stoplight. Again the car acceleration pedal would not respond. I put on my flashers and returned to the vehicle. I turned the car off and restarted it and was able to drive it home on side streets. I did not want to get back on the freeway. I had the car towed to the Hanlee Hilltop Hyundai in Richmond California. They performed a computer check and no error code came up except for an external charger error code. Our Ioniq 5 is charged with our wall box charger and has performed with no problem. It has worked with our Kia Niro EV also without problem. I fear there is a problem with this Electric Vehicle and do not feel safe driving it. I have initiated a buy back with Hyundai. I wanted to report the problem to this government agency in case there is a larger safety problem with this model year.

The ICCU unit has failed after 10 days of driving of the brand new 2025 Ioniq 5. It gave me a warning that the battery has failed while I was waiting on a signal light, and the car started limiting my speed. The car continued to get slower and slower, then it says battery regeneration failed at one point. The fastest I could go at one point was 30 mph. It was dangerous as I need to make sure the cars behind me don't come at me. When going uphill, I was only able to drive in 20mph. The car was taken back to the dealership to get serviced. They confirmed that the ICCU unit and the fuse have failed and my car will need a replacement.

I notice a strange pulsing/hesitation when accelerating at partial throttle (maybe 10-25%) between 60-65MPH. It's quite alarming, because it feels like the electric motor is cutting out momentarily. I notice the same pulsing/hesitation during regenerative braking at the same speeds (as with the acceleration, it is only noticeable at partial regen). The dealer confirmed that they've noticed the same behavior on other new Ioniq 5 vehicles, but they don't have a fix. I don't know the safety implications, but I worry about the electric motor cutting out and affecting my ability to control the car during acceleration or regenerative braking.

The high-voltage traction battery on my 2025 Hyundai Ioniq 5 Limited RWD failed unexpectedly around [XXX], when the vehicle had approximately 1,250 miles on it and was just over 3 months old. The car had been parked in my driveway with about 80% charge while I was away for several days. When I attempted to drive it, the vehicle would not shift out of neutral. No warning lamps or error messages were displayed before the failure. The vehicle was towed to Van Hyundai in Carrollton, TX on April 3. While loading it onto the tow truck, the 12V battery completely died, disabling the electronic parking brake and preventing the vehicle from being safely secured. After an extended wait, a Hyundai field service technician diagnosed the failure as a fault in the traction battery, requiring a complete replacement. I was told the part is currently unavailable and has no estimated arrival time. The issue has been confirmed and documented by the dealer and the field technician. This failure renders the vehicle undriveable and puts both safety and financial reliability at risk. Not only was I unable to move or secure the vehicle, but it has also been out of service for over two months with no resolution in sight. The failed component is currently in possession of the dealership and should be available for inspection upon request. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)