2025 Hyundai Ioniq 5 electrical system problems

“Second failure of the Integrated Charging Control Unit (ICCU) on this 2025 IONIQ 5. The ICCU stopped charging the 12-volt battery, leaving the vehicle unable to start. This is the second time the ICCU has failed and required replacement in approximately one year. The vehicle was towed to the dealer. ICCU failure can cause a loss of drive power while driving; this failure was discovered while parked. Earlier model years (2022-2024 IONIQ 5) are covered by recall 24V-868 for this same defect; this 2025 vehicle is outside that recall population and has now failed twice.”

“On XXX, while driving my 2025 Hyundai Ioniq 5 on a local road, the vehicle suddenly lost power and would not accelerate beyond 40 MPH. There was no prior warning. I had not yet merged onto the expressway. Had this happened at highway speed, I would have been unable to keep up with traffic, which would have created a serious risk of a collision. I continued driving at reduced speed until I could safely pull into a gas station. Once stopped, the instrument cluster displayed "Stop vehicle and check power supply." About 10 minutes later, with the vehicle parked and still on, it displayed "Check 12V battery. Stop safely and engage parking brake." Roughly 10-15 minutes after that, the vehicle shut down completely and could not be restarted. The vehicle was towed to Gerald Hyundai in [XXX] on that day. On XXX, the dealer confirmed that the Integrated Charging Control Unit (ICCU) and a fuse failed and had to be ordered for replacement. The vehicle is less than one year old. I am aware of numerous reports of ICCU and 12V battery failures on this model, and my experience is consistent with them. A sudden loss of propulsion while driving is a safety hazard, and I am…”

“I am writing to document my case regarding my leased 2025 Hyundai Ioniq 5 XRT. Vehicle: 2025 Ioniq 5 XRT, VIN [XXX] Lease start / delivery date: Odometer: 4,368 miles Servicing dealer: Stevinson Hyundai, [XXX] Case number: XXX What happened: On Saturday, XXX, while I was driving, the vehicle displayed "Stop vehicle and check power supply" with the red 12V battery warning and the master warning light, and power was limited to approximately 25 mph. The high-voltage battery was at 66 percent. I was able to get the vehicle home at reduced speed, and Hyundai Roadside Assistance towed it to the dealer the same day. The symptoms are consistent with an ICCU failure, pending the dealer's diagnosis. Photos of the instrument cluster are attached. I consider a sudden loss of drive power at 4,368 miles to be a safety-related defect, and I have reported it to NHTSA. My situation: This is one of two vehicles in our household, and both of us need to get to work. The dealer is about 30 miles from my home. I am without transportation as of September 19. What I am requesting: 1. Written authorization for a rental vehicle starting immediately and continuing until my vehicle is…”

“On 8/30 my vehicle experienced a power loss on a highway (reported here separately). I took the car to the dealership and they could not replicate the error and gave the vehicle back to me on 9/4. Later that day I had to drive 2 hours north to a wedding in the mountains. At 9:30pm my vehicle experienced a full drive power loss on an unlighted, curving, rural 2-lane mountain road in an area with minimal cell phone service. I tried to restart the vehicle several times and could not get any power. I called roadside assistance and had to wait over 2 hours in the dark on a winding mountain road for the tow truck to find us and then be towed 40 minutes away to the nearest dealership where my car is still sitting waiting to be looked at (2 hours away from where I live)”

“Full electrical power system failure. Heard a loud pop noise emanating from under the rear seats of the car. The power. Failure lights came on and the car lost power. We were able to get the car to slowly drive back to the garage where it completely shut down and was inoperable from that point on. Car has been towed to the local dealer for diagnostics and repair.”

“While driving this EV with cruise control on, the dashboard suddenly showed a message that “Smart Cruise Control conditions not met”. Attempting to re-engage the cruise control did not work and then the vehicle suddenly lost all propulsion (pressing the accelerator did nothing). The car quickly slowed to about 20 mph before we could maneuver it to the shoulder and turn it off. After a couple minutes, we restarted the car and drove it to the dealer. There were no other messages or warning lights or indicators. The dealer could not find anything wrong and asked us to pick up the car and resume using it. We use both a home charger (Emporia) and roadside (Tesla) chargers.”