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.
2025 Hyundai Ioniq 5 electrical complaints
Page 4 of 9: complaints 71 to 100 of 229, newest first, as owners wrote them.
ICCU failure causing the car to go into low power mode. Tow required to get the car to the dealership for repair.
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.
After hearing a sudden loud pop, my car lost all power. I was able to pull to the side of a busy 2 lane road. It was dangerous and scary to be stranded alone on a very busy road. The car had to be towed to the dealership. It took 48 days to replace the ICCU, fuses and the coolant. The service manager said this is a known issue.
ICCU failure
The ICCU failed. The car makes a loud pop sound and then the dashboard lights up. You are stranded wherever it fails because the car isn’t drivable after it happens. The car was inspected by the dealership. There were no warnings before it happened.
While charging the vehicle, we heard a loud pop. After starting the vehicle there was a warning to check the electric vehicle system. The car max speed was limited to about 20mph while driving home (it was night and the dealership was closed). The following morning while driving the car to the dealership, a new warning came on to stop the vehicle. A few minutes later, a new light came on showing a turtle icon and the car would only go about 3-4 mph. I barely made it through the busy intersection and was able to pull over before the car completely died. At that point, nothing worked: no electronic locks, no hazard lights, or other safety measures. The car was towed to the dealership (1/2 mile away) where it was diagnosed with an ICCU and fuse failure. Due to a part being backordered, the car sat at the dealership for 86 days before being fixed and returned.
I started driving and pulled out of a parking lot onto a busy road. The ICCU had failed unknownst to me and as I was underway the car started losing power and the dashboard lit up with warnings about the electrical system. I was limited to 25 MPH for a brief time and struggled to turn off into a parking lot amongst much faster traffic. While doing this the car slowed further to 10 MPH. I limped at this speed into the parking lot at which point it turned off and lot all power. This happened over the course of about 30 seconds. If it had happened on a busier road I would have been in trouble. On the highway and it would have been extremely dangerous. It was dangerous enough as is with cars passing me 20+ MPH faster than my car could go. This all occurred with no warning, and is due to an issue with the ICCU in the car that Hyundai has known about for years and has refused to address or fix.
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 fuse blew during operation, car went into limp mode. Vehicle is currently being serviced under warranty through Hyundai
The ICCU (and the associated fuse blew) while I was driving and it caused the car to be slowed immediately to approximately 20 MPH. This apparently is a huge issue with this vehicle.
My 2025 Hyundai Ioniq 5 has experienced repeated catastrophic 12-volt battery failures following an ICCU (Integrated Charging Control Unit) failure in November 2025. The ICCU failure caused the vehicle to lose power in traffic and required towing. The ICCU was replaced but the 12-volt battery was not replaced. Since that repair, the vehicle has experienced repeated electrical failures. The 12-volt battery dropped to approximately 3.5 volts on one occasion and approximately 1.72 volts on another. These voltages were measured and documented on video using multiple multimeters before any jump start or charging. At these voltage levels the vehicle cannot unlock doors, power systems, or operate normally. The vehicle required towing by AAA. The dealership has repeatedly recharged the battery before testing and then claimed the battery “tests good,” refusing to replace it under warranty. Numerous owners online report similar failures where ICCU problems lead to repeated 12-volt battery collapse and vehicle immobilization. Because loss of 12-volt power can disable critical vehicle systems and leave the vehicle stranded or stopped in traffic, I believe this represents a potential safety defect. I don't have the repair reports from the dealer scanned in but I can if you want them. ICCU is known failure and recall but for some reason our car doesn't appear on any recall list. 12V battery that drops below 6V is deemed unsafe and bad and 3 times (including this time) it's been below 6v but they don't believe it's a bad battery.
While traveling at highway speeds, the vehicle suffered a catastrophic and sudden loss of motive power. This resulted in a dangerous situation with no immediate ability to maintain speed in traffic. The manufacturer (Hyundai) identified a failure in the Integrated Charging Control Unit (ICCU). Despite a formal 'Notice to Cure,' the manufacturer refused to replace the 12V battery which was stressed during the failure, potentially leading to a repeat high-speed power loss event. This is a known issue with the E-GMP platform (Ioniq 5) that poses a significant unreasonable risk to public safety.
The vehicle exhibited charging failures on multiple occasions over the course of several days after being connected to a Level 2 home charging unit overnight. On repeated mornings, the high-voltage battery was found to have not charged. The vehicle also exhibited intermittent slow charging behavior during this same period. Approximately six months prior to the charging failures, the 12-volt auxiliary battery was found to be completely discharged. During this same period, the vehicle was started on one occasion to find that every warning and alarm indicator on the dashboard had triggered simultaneously. The vehicle was completely inoperable at that time. After several minutes, all warning indicators cleared and normal operation resumed without any intervention. The vehicle was brought to an authorized Hyundai dealership on March 6, 2026, where the technician diagnosed the root cause as a failed Integrated Charging Control Unit (ICCU). The ICCU is responsible for managing both high-voltage battery charging and maintaining the 12-volt auxiliary battery; a failure of this component can result in loss of charging capability, auxiliary battery drain, and potentially a complete and sudden loss of vehicle operability. As of the date of this report, the vehicle is awaiting parts with an estimated repair time of approximately one week. The repair is expected to be covered under the manufacturer's warranty. This failure occurred with fewer than 10,000 miles on a 2025 model year vehicle. Based on publicly available owner reports and online forums, ICCU failures appear to be a recurring issue across multiple Hyundai IONIQ model variants.
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.
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.
While driving, car displayed a check electrical vehicle system warning light. The 12 volt battery completely died and could not maintain charge resulting in slower and then complete loss of propulsion. Towed to dealer and the following Monday determined it was an ICCU failure. Part is back ordered but verbally told on 2/24/2026 that part would be delivered in two weeks. We'll see!!! If this issue occurred while driving on an interstate at full speed with traffic it seems this might result in an accident since the max speed dropped to 25 MPH and then 12MPH after warning before being able to safely pull over.
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.
I couldn’t start the car. I had to tow it to nearest dealership. I waited one week to get diagnosis and was told about ICCU failure. It took 45 days in the shop to get it fixed.
Check electric vehicle system light came on and power slowly diminished which meant the car was unable to sustain highway speeds. Had to be towed to dealership.
ICCU unit failed in parking lot leaving us stranded. Over 30 days to repair. Common issue. Luckily we weren’t on the road as the vehicle goes into a very short limp mode which may not allow time to get off a busy highway.
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.
On [XXX] while driving the car on a city street in Northhampton, MA, I heard a loud "pop" and there were multiple warning lights, beeps and messages indicating there was a problem with the electrical system. The car slowed dramatically and I was unable to drive at a safe speed to keep up with traffic. The car slowly lost power and I was able to pull over to the side of the road. The temperature was 15 degrees F - very cold, no heat and I had to stay with the car in freezing cold temperatures to await transport via tow to the local dealer. The tow service required that someone be with the vehicle in order to receive a tow. The dealer diagnosed the car with a failed ICCU - a well-known, increasingly common issue with these cars - and said there were already 10 Ioniqs on the lot awaiting replacement ICCUs. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
I was on the highway going at approximately 60mph when the car without any warning reduced speed to first around 40mph and then to 20mph all within a matter of a few minutes, causing me to pull over to the side of the highway. Luckily, I wasn't injured. I exited the highway, called my insurance company Geico and had the vehicle towed to the dealership where I leased this brand new vehicle from just about 7 months ago on a 2year lease. The dealer was kind enough to provide a smaller loaner vehicle but had no idea when my car would be returned, as there were others with similar failures ahead of me that were waiting for the part to arrive. Apparently, this is a known failure issue of the ICCU that Hyundai has done a poor job of addressing. I continue to make my lease payments while waiting for the part to arrive. In the meantime, I wanted to let the government know of my experience and how this could have had a disastrous effect on my family and other families with a similar build.
Drove 50 miles. Charged car at a supercharger. Unplugged car normally. Pushed start normally. Heard a light “pop” sound. Car would drive but with low acceleration. Warning lights came on. Then bright “stop now” lights and beeping. Then it died in the parking lot and would not start at all.
The ICCU failed under normal utilization The vehicle went into limp mode which changes expected driving dynamics The dealer confirmed ICCU failure and the manufacturer has confirmed the vehicle is a lemon as per MA state law No warnings prior to the failure
Turned on my car one day after charging and heard a 'pop' from the rear of the car, followed by warning lights activating on the dash and an electrical system error message. I had the car towed to the dealership (Santa Monica Hyundai) and they confirmed the issue was an ICCU component failure. There were no warning signs or issues before the failure. The dealership currently has no ETA for a fix.
My Ioniq5 experienced a failure of the Integrated Charging Control Unit (ICCU) while driving. There was a loud "pop" noise from the back seat that occurred while driving, and afterwards the car experienced an unexpected braking/deceleration and was unable to maintain a speed over ~30MPH. After the "pop" noise -- a "Check electric vehicle system" alert appeared on the dash, and an alert that the car had entered a limited power state also appeared a few minutes later. My safety was put at risk due to the car unexpectedly decelerating and then losing the ability to maintain speed while driving on a busy highway. Other's safety was put at risk due to my limited ability to maintain speed and not impede traffic. There was no warning's prior to the sudden failure to indicate there was anything wrong with the vehicle. The car needed to be towed to the dealer due to the limited state the car was put in. It was confirmed at the dealership that the ICCU had failed and needed to be replaced. It was also confirmed at the dealership that the replacement part was the same as what had failed, which is concerning for mine and other safety that this is at risk of occurring again.
While driving, loud pop sound came from rear of car. No prior warning or lights before this. Car immediately displayed a check electrical vehicle system warning light. Luckily we were somewhere were we could pull over immediately. Towed to dealer and they determined it was the ICCU that popped. Due to the ICCU failure, we could have completely lost car power if we didn't have somewhere to stop. Currently car is sitting at dealer with no ETA for getting fixed. Part is not available .
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