2025 Hyundai Ioniq 5 Powertrain & Transmission Problems

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.

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.

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

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.

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.

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.

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

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.

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

ICCU needs to be replaced.

What failed: On February, 6, 2026, I experienced a complete failure of my Ioniq 5's electrical system due to the ICCU failing. Heard a loud "pop" and eight seconds later it reported a warning to check the vehicle's electrical system and 24 seconds after the pop it then chimed repeatedly saying to pull over immediately and come to a complete stop. The vehicle is currently at a nearby My safety: Once I was able to hobble the car off the side of the road, it left me in a dangerous situation. The vehicle was such in a state that the hazard lights were not operational and I had no way of getting any heat. (It was 20F with a wind chill down to 14F.) It also happened in a bad part of town, meaning that I did not want to leave the vehicle unattended for a tow truck. This also occurred 60mi from home. Reproduced: The dealership it was towed to is not open until Monday, February 9, 2026 but the tow's rescue battery made the system run enough to report the Diagnostic Trouble Code of "P1A9096". Doing a quick search online for that shows a number of cases with the same problem. While waiting for the tow, I tried to start the car a number of times to no avail. Inspected: Not yet, see "Reproduced" section above. Any other signs/symptoms? Nothing until the "pop" itself. Once that happened, basically every warning icon showed up on the instrument cluster/screen.

Vehicle experienced a dashboard alert, "Check electric vehicle system." The car produced an OBD code: P1AD3(00). Upon taking it to the dealer, they determined that the EV required a new high-voltage battery.

2:27 pm on 02/06/2026. Pop heard from the trunk area, then displayed "Stop vehicle and check power supply," the car lost power and then became completely immobile. The car has 3500 miles on it. Bluelink app showed "Everything looks good."

Main battery failure, can not charge, can not drive car. Warning light(s) on dashboard. High voltage battery needs to be replaced.

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.