2025 Hyundai Ioniq 5 Electrical System Problems

Vehicle unexpectedly ceased to work. A loud pop sound then a message to check electrical system. Vehicle reverted to “limp mode” leaving me at a max of 15 mph. Terribly unsafe and extremely, concerningly widespread ICCU failure across Hyundai EV models For 5+ years is unacceptable

I heard a loud pop and my car died and was undriveable in about 5 minutes. Told it was my iccu failure and fuse popping. Apparently this is a common issue. I was almost killed as I was kn thr interstate and needed to be towed. Nothing worked

2025 Hyundai Ioniq 5 XRT, VIN [XXX] . Four 12V battery failures requiring jump-starts in under 800 miles of ownership. No fault codes stored at any failure event. Visit 1 (01/12/26, ~100 mi, RO HYCS79193): Factory OEM battery confirmed failed by GDS. Replaced under warranty. Visit 2 (01/30/26, ~300 mi): Second OEM battery confirmed failed by GDS. Replaced. Visit 3 (03/31/26, ~800 mi): Aftermarket AGM tested healthy but required jump-starts. GDS recorded 12V SOC dropping from 99% to 21% then recovering to 79% — consistent with intermittent LDC output interruption, not parasitic drain. Hyundai Techline contacted. No repair performed. Visit 4 (04/08/26, ~800 mi): AGM measured 5.5V, required jump-start. Maryland Lemon Law notice submitted to Hyundai Motor America. The Ioniq 5 has no alternator — the 12V system depends entirely on the ICCU’s DC-DC converter. Hyundai has acknowledged this ICCU defect under NHTSA Recalls 24V-204 and 24V-868, covering 2022–2024 Ioniq 5 models. The 2025 model uses the same E-GMP platform and ICCU architecture but is excluded from both recalls. My symptoms — repeated battery failure with no DTCs, confirmed SOC anomaly on GDS, failure across two battery chemistries — match the subclinical LDC failure mode documented in those recalls. A Hyundai North America case is open and engineering has been engaged. No repair has resolved the defect. I request NHTSA investigate whether the 2025 Ioniq 5 is affected by this defect and consider expanding Recall 24V-868 to the 2025 model year. Please add this complaint to Investigation PE23-011. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The 12V battery in my 2025 Hyundai Ioniq 5 failed under normal use, causing repeated loss of vehicle function. Voltage measured ~12.3V at rest, dropping to ~12.0V when opening the door, and collapsing to ~11V then ~9V under light load (headlights), resulting in system shutdown. After a failed start attempt, the vehicle experienced a brownout followed by a complete loss of 12V power for approximately 5 minutes while the battery was replaced. After installing a known-good replacement battery, the vehicle powered up and the instrument cluster displayed “The vehicle is On, Ready” without pressing the start button or providing any operator input. Due to safety concerns, I did not attempt to move the vehicle. Concern: After a complete loss of control power, the vehicle appears capable of entering or reporting a Ready state without explicit operator action. A vehicle should not present or enter a drive-ready state following a power interruption without a new, deliberate user command. This behavior is unpredictable and could present a safety risk if the system were to enable propulsion or mislead the operator about the vehicle’s state. At minimum, it indicates improper state recovery after a power failure.

The vehicle flashed a warning not to drive the car because of an electrical system problem after a loud popping noise. I had the car towed to a dealership who told me the Integrated Charging Controller Unit had failed. The car is only 9 months old with under 5000 miles.

March 19, 2026, the car left my 18 y.o. daughter stranded at 10:00pm in a store parking lot. The car was fine when she went into the store. When she went back to the car, it was completely dead. No power at all. I had to pick her up to bring her home and left the car overnight. Called AAA the next morning. I have already previously reported about this car a few months back when it was in the shop for 3 months. Then, the ICCU and wiring harness were replaced a couple times.

I am submitting this complaint regarding a serious safety issue with my vehicle, a Hyundai Ioniq 5, which I purchased new and which currently has only 4,795 miles. The vehicle remains fully covered under the manufacturer’s warranty. Yesterday, March 19th 2026, while driving on a heavily congested street, the vehicle suddenly displayed a warning message stating: “Stop Vehicle and Check Power Supply.” Immediately after, the car began to significantly lose power and slow down in active traffic. This created a dangerous situation, as I was forced to pull over abruptly in a crowded roadway, putting my safety and the safety of others at risk. Due to the severity of the issue, I contacted Hyundai roadside assistance, and the vehicle was towed to Safford Hyundai for inspection and repair. I was informed by the dealership that repairs could take up to four months, and I was not provided with a loaner vehicle or alternative transportation. As a result: I am currently without a vehicle for daily transportation, including commuting to work I have experienced significant stress and anxiety due to the sudden and dangerous nature of the incident I am left without a reasonable remedy despite the vehicle being new and under full warranty This situation raises serious concerns regarding vehicle safety, reliability, and Hyundai’s failure to provide adequate support or transportation during an extended repair period. Given that this is a new vehicle with a critical failure that compromises safety, I am requesting: Immediate assistance with a loaner or rental vehicle at no cost A clear timeline and communication regarding repairs Consideration of further remedies if the vehicle cannot be repaired within a reasonable timeframe, in accordance with applicable consumer protection laws I believe this issue represents a significant defect that substantially impairs the use, value, and safety of the vehicle.

ICCU FAILURE STOPPED ON ROAD

Backing out of driveway on 3/13/26, warning message appeared on dashboard- "Stop Vehicle and Check Power Supply." Had car towed to dealership (Ourisman Hyundai, Bowie, MD). On 3/16/26, service department advised the ICCU needed to be replaced, part was on back order with no ETA.

Driving and lost power in vehicle it wasn't able to accelerate and resulted in getting stranded. Power would then be restored and then lost randomly. Dealer said it was the ICCU that was faulty.

I was sitting inside my parked car when I heard a loud pop sound from around the back trunk area, like a computer chip exploded. The car alerted me to check the ECS or battery management system and told me to pull over to safe location and don’t drive anymore. I relocated the car to another location and parked it but when I tried to start it again, nothing would power up. It appears the 12V battery has died. I contact Hyundai roadside assistance for a tow to my closest Hyundai service center. Hyundai confirmed that the ICCU and 12V battery needed to be replaced.

ICCU completely went out. Had to have the ICCU replaced with an upgraded one, fuse replaced and software was updated.

Car suddenly went into limp mode while driving and completely vehicle shutdown soon after. It has been diagnosed at dealership that it is ICCU issue. It would be very dangerous if this happens on highway.

ICCU failed unexpectedly at having only 1780 miles. All power failed within 15 minutes of an alert. Car could not even be put in park. Had to keep foot on brake until tow arrived.

ICCU and fuse iccu and fuse p1a9096 error. Car had electrical warnings and lost power 2 miles from home with only 7000 on vehicle. Car was only able to go 10mph to get home. Parts on back order from Hyundai.

Integrated Charging Control Unit (ICCU) failure leading to a loud popping sound from the rear, total loss of drive power.

The Integrated Charging Control Unit (ICCU), part number 36400-1XAD5, failed on my 2025 Hyundai Ioniq 5 SEL RWD at 2138 miles. The ICCU is responsible for charging the 12V auxiliary battery from the high voltage traction battery. DTC P1A9096 was recorded on 03/02/2026. When the ICCU fails, the 12V battery drains because it has no charging source. The vehicle becomes undrivable as all vehicle systems depend on the 12V battery. The vehicle had to be towed on a flatbed truck to Hyundai dealer for diagnosis and repair. The failure was confirmed by the dealer using their diagnostic tools. This is the same ICCU failure mode covered by Hyundai Recalls 257 and 272 for 2022-2024 Ioniq 5 vehicles, however the 2025 Ioniq 5 is not currently included in those recalls despite using the same ICCU architecture. The failure at only 2138 miles on a 2025 model indicates the underlying defect was not resolved with the model year refresh. If this failure had occurred while driving at highway speed rather than while the vehicle was stationary, the progressive loss of motive power could have created a serious safety hazard. NHTSA should consider expanding the existing ICCU recall to include 2025 Ioniq 5 vehicles.

While leaving Grandson’s Basketball game parking lot, we heard an audible “pop” and began traveling while the dash lit up with warning lights. We were only a few miles from home so I continued on at a maximum of 25mph, which was the max available. We contacted Hyundai and arranged for a tow the next day. The dealer, Heritage Hyundai, received the vehicle and it’s been there for over a week. The car’s code system indicated a ICCU fault. The dealer told me no recalls were made on our vehicle.

I had washed my vehicle in my driveway. As I was drying it off, I heard a loud pop sound. When I went to put the car back in the garage, there was a warning displayed on the dash advising to check the vehicle electrical system. I immediately opened the MyHyundai app and it had a warning of an issue with the elecrtrical system and advised to schedule service. I had had no issues with the vehicle or its operation prior to this suddenly happening today. I fear that this is an ICCU issue as I have seen numerous complaints on forums and Reddit of over 90K 2025 Ioniq 5 vehicles this year alone having this issue. That’s an awful lot of vehicles to have the same issue.

Integrated Control Charging Unit (ICCU) malfunctioned. Turned car on and heard a popping noise, then car displayed check electrical system. Code P1A9096.