2025 Hyundai Ioniq 5 Complaint Log

ICCU blew while driving and immediately slowed me to 45 mph

Vehicle shut down with minimal warning due to “integrated charging control unit” failure. Vehicle left my wife stranded on rural road. Current mileage is 12k.

ICCU failed and blew high power fuse. Car displayed warning and only drove slowly. I went to the selling dealer and they confirmed the ICCU and fuse failure.

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 was driving on the highway when the car suddenly flashed a “check power supply” warning and then immediately shut down. I was traveling approximately 55 mph when the car came to a sudden stop and I was almost rear-ended as a consequence. I was not rear ended because I had a wide shoulder to immediately pull over onto, but if this had happened in a location without a shoulder, it likely would have caused an accident.

I was driving my vehicle on a freeway with 3 passengers when i heard a muffled pop or thud from behind me. A rear passenger confirmed that it came from beneath the rear seat towards the left side of the car. The vehicle speed immediately dropped to less than 40 mph and a warning message appeared on the dash "Check electric vehicle system". I later noticed a red battery icon appear on the left of the dash. I pulled over after leaving the freeway and attempted to resolve the issue by turning off the car, then restarting it. The notice and red battery icon still appeared. I feel that this sudden reduction in speed is a safety issue because I could have been driving at a higher speed (65-70 vs 45-50). Following cars may not have been able to stop in time, or I cuold have been forced to attempt to get off the road by entering lanes with vehicles travelling at a much faster speed. I was about 5 miles away from home on the start of a 400 mile trip so decided to turn around. Back at home I discovered that a new DTC code had been thrown during or after this event - P1A9096. I transferred to another person's cart to complete the trip, and on return arranged for the car to be transported to a manufacturer recommended dealership to check the issue. The Dealership service department conducted diagnostic tests and determined that the issue was caused by an ICCU failure. The have placed an order for a replacement ICCU unit and fuse. Prior to this event there had been no dash light warnings or trouble codes thrown.

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.

On April 1, 2026, my 2025 Hyundai IONIQ 5 experienced a cascading electrical failure. The vehicle first displayed a warning about a problem with the on-board charger, followed shortly by an alarm and the 'Stop Vehicle and Check Power Supply' warning with a red 12V battery indicator, rendering the vehicle unsafe to drive. Had I been on the freeway this would have been extremely dangerous. My Bluelink diagnostics history confirms three fault codes from that date: P1A9096 (ICCU fault, Electric Vehicle / Air Flap system, still Open as of 4/3/2026), and P056216 (Voltage Regulation fault, Hybrid Control system, reported twice), consistent with a cascading ICCU failure causing 12V system collapse.

Car charged as scheduled overnight 3/28/26 but was dead the morning of 3/29/26 and when it was jumped gave error "Battery overheated, please stop and exit vehicle" and "check electrical system" - vehicle has been in shop for 16 days, no diagnosis except that it "probably" needs a HV battery.

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.

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.

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.

ICCU FAILURE STOPPED ON ROAD

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.

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.

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.

ICCU unit of the car short circuited right in middle of driving and caused the car to go in "limp mode". Sudden pop noise and slowdown created situation where car could be rear-ended. The part has already caused recall for prior model years, but model year for my car is not included in the recall. Based on internet search it is a continued and widely prevalent issue, manufacture has not done enough to fix this and a recall needs to add new model years. Additionally, the parts are backordered and there is no immediate fix.

Car showed electrical problem on the dash. Car would not start.

The Integrating Charging Control Unit (ICCU) failed while attempting to accelerate onto an Interstate Highway. The car then went into 'Limp' mode which only allowed a sped of 20 mph. Luckily I was able to get to the next exit without getting hit by car already on the highway going 60-70 mph. The car showed both a 'battery warning' and a 'car over heating' symbol (the car has no engine, so assume it was the battery that over heated). The ICCU was recalled by Hyundai in the 2022-2024 Ioniq5 models, but was not recalled in the 2025 model (which I own). My suggestion is that the 2025 Hyundai Ioniq5 should be added to the the same recall as the 2022-2024 models since it is exhibiting the same problem.

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.

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.

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.

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 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.

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.

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 attempting to leave home, the 'Check Electrical System' warning came on. The vehicle entered a 'safe mode' and was unable to accelerate. The car was towed, and the dealer confirmed a complete failure of the ICCU and associated fuse (DTC P1A9096). This is a known issue (Recall 24V-204) and created a dangerous situation.

ICCU failure at 5308 miles. heard a loud pop while driving and 12v warning system errors

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

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 .

While driving, heard a POP sound, followed but multiple warnings to stop vehicle and check the electrical system. The car went into turtle mode. luckily I was close to home, but any other situation could have been dangerous. This is a commonly known issue with these Ioniq 5 vehicles. The ICCU fails and can no longer charge the 12v battery, causing loss of electrical systems and possibly even the ability to have hazards on if you are stuck in traffic.

ICCU failure. Vehicle has 5200 miles on it. A loud "pop" was heard then the vehicle went into "limp mode" and restricted speed to 30 mph. After about 10 miles the car totally lost power and wouldn't start. Warning l messages said to get it serviced which is what I was attempting to do.

ICCU confirm dead by the dealer. IONIQ 5 2025 AWD. only had this car for 5 month, 4900 miles. vehicle stopped at the middle on the highway. luckey, no accident occur. no part avilable, no ETA for fix, no loaner from dealer.

The vehicle was in the middle of a u-turn when the ICCU fuse suddenly and without warning blew. Display warning messages came on to "check electrical system". Car was able to drive in "limp mode" at about 40 mph on level roads, but not more than 25 mph on any uphill. This is a well known problem with Hyundai EVs. It will be towed to a dealer to confirm. It felt extremely unsafe to be in the middle of a turn on a public street and have the car power system fail. Luckily there was minimal traffic at the moment. A few minutes earlier or later would have been on a heavily trafficked road

ICCU failure

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.

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.

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 failure causing the vehicle to be inoperable

On Sunday, 2/15/26 while backing out of my garage into the driveway, I heard a "pop" sound from the rear and the vehicle stopped and shut down with multiple warning/alerts on the dash. The error code reported was DTC P1A9096 which is indicative of an ICCU (Integrated Charging and Control Unit) failure as widely reported here and online by other owners. Vehicle was towed to the dealer and is currently awaiting diagnosis.

ICCU failed less than 5k miles into my lease. I am now no longer able to drive the vehicle and there is no eta on getting a replacement since it’s on back order

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.

ICCU needs to be replaced.