2023 Hyundai Ioniq 5 Powertrain & Transmission Problems

While driving the vehicle, the ICCU failed. The vehicle shut down in the middle of traffic without any warnings.

Having the same ICCU Failure that all other Ioniq 5 owners have. On February 26th, I was heading to work when I heard a pop and car displayed warning lights saying check EV system and stop safely. Car was limped home and towed to dealer. Was told fix will take a month.

During level 2 AC charging the circuit breaker in the house tripped. Tried again on a level 1 charger that came with the car and again it tripped the home circuit. Again, the car overloaded the house electricla system to a point it tripped the circuit breaker. Car taken to dealership for repairs. Dealership trouble shooting identifed failed ICCU with burnt connecter pins. HyundaiCase Management number 42152269 THIS IS A FIRE HAZARD FOR THE CAR AND HOUSE.

7 incidents of electrical drive problem incidents 1-3car would not start despite full battery Incident 4 same thing and car went to dealer, they said know problem and they would fix it overnight by downloading new software and charge about 400 for new 12V battery Incident 5 While on freeway using cruise control card speed varied wildly I disabled cruise control and with manual throttle same problem Incident. 6 In middle of traffic car went blank no lights or anything. I tried to restart 3 times and nothing, so I sat back and was in process of calling for tow. I did nothing and car violently accelerated and turned into steel pole. Only injury I had was bump on head that went away. As soon as the ghost mode engaged I hit the brake which likely prevented more damage to me, but front end of car was damage Incident 7 While I was detained someone else drove car to dealer and driver reported felt like driving on ice with rapid direction and speed changes Currently at dealer where neither dealer or Hyundai will take of problem and I get run arround from Hyundai and dealer. Dealer claim the don’t know is the problem. Dealer has had car for approximately 65 days Bottom line, the car is totally unsafe to drive and very dangerous

First time this occured we were driving in the winter and the car randomly shut down and started saying "Electrical Fault" or something of the sort. Turns out it was an ICCU issue. We got this replaced last year. Turn around 6 months later and the same thing happened again, but in an intersection. From my understanding when the ICCU fails the entire car basically goes into limp mode and prevents you from driving. Super dangerous and very hard to trust moving forward. Both of these issues have been confirmed by the dealership.

While driving, the vehicle displayed a “Check Electrical System” warning and experienced loss of propulsion power. The vehicle became inoperable and required towing. The Hyundai dealer diagnosed failure of the Integrated Charging Control Unit (ICCU), a known failure point on this platform. The ICCU is currently on backorder with no confirmed repair date. This failure creates a serious safety risk, particularly if it occurs at speed or in traffic. I no longer feel the vehicle is safe or reliable to operate.

Had an ICCU failure that prevented the car from being able to drive.

After having service done for the past two ICCU recalls months and months ago, I’m driving along today and hear the loud pop that everyone else reports. My car immediately went to a reduced power state where I was able to limp a bit further until I lost all power. I had to have the vehicle towed (by a wheel lift/dolly equipped wrecker - do not allow a flatbed they’ll drag your car into the truck) to the nearest dealership and now await to hear how long I’ll have to be without it.

ICCU failure, left stranded for a tow

There was sudden power reduced and turn to the limp mode(Turtle symbol popped up). After pull over my vehicle to highway shoulder, the vehicle became total power loss. Unable to drive anywhere. It was a dangerous situation for my family. We waited tow car and took my vehicle to Hyundai dealership which located close to my house. They diagnosed my car and after a day. They told me it needs to be replaced a ICCU assembly and Fuse. There was no ETA for the parts. They provided me a loaner’s car. After about 15 days, they fixed and I was able to take my car.

While stopped at a stop light, "check electrical system" warning flashed on instrument panel without any prior warning or malfunction. I was only able to move the car about 50 feet before all power and controls failed. I was in a middle lane and was barely able to move the car out of traffic. Tow truck driver with a large jump start battery pack was able to give it enough power for me to crawl it onto their flatbed, my small lithium jumpstart pack was only enough to get the rest of its doors unlocked. Battery temperature was about 30 degrees F, state of charge 75 percent, had been driving from home less than 10 minutes, car had been sitting outside for a few days. Problem diagnosed as ICCU failure by dealer service department, now waiting on replacement part to complete repair.

The car had no power on Monday [XXX]. It was taken taken to Tasca Hyundai in Hartsdale NY. The service manager told me it was the ICCU and 12v battery. This had previously been repaired on 12/11/24 under recall according to Hyundai's own records. The current service manager has no idea when the part will be available, possibly not for weeks. The car has been serviced according to Hyundai's maintenance schedule and recall notices. In fact the car went for maintenance one week prior to the part failure. No recall notice for this failure has been issued INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

While driving my 2023 Ioniq5 I got a warning on the dashboard about losing power and immedately the car slowed itself down to about 15 MPH, once I was able to get to a safe spot to pull over I stopped the car and it would not start again. I had it towed to the dealer and it has been a week and the ICCU is still on backorder. No idea when I will have the car back.

Vehicle experienced sudden loss of power while driving at highway speed. While driving on the interstate at highway speed in dark, snowy, high-traffic conditions, the vehicle displayed a warning about an electrical system fault and instructed me to “stop safely.” The vehicle immediately lost some propulsion and ramped down speed. We were only narrowly able to exit the highway before it would not move further. We were very lucky that no one hit us- it is extremely unsafe to drastically decrease speed on highway. Our family was in the car and it was very, very scary. We were able to use the heating system while parked for a few minutes before we lost all power completely. The vehicle was towed to a Hyundai dealership and is completely inoperable. The service manager stated the failure is consistent with a known ICCU (Integrated Charging Control Unit) failure. The dealership reports having many Ioniq vehicles with similar ICCU failures awaiting backordered parts, with no estimated repair timeline.

ICCU failed while at highway speeds (65mph). Car went into 'turtle mode' limiting the car to 10mph. No warnings were provided prior to the incident. I was in the left of three lanes and had to make emergency actions to get to the Right shoulder across traffic. Traffic was obstructed. Was left stranded until a tow truck was available. Dealer confirmed ICCU failure.

High-voltage battery system failure causing complete loss of propulsion. Vehicle entered "turtle mode" (reduced power warning) at 25% charge, then became completely immobile — unable to move even on flat surface. This has occurred multiple times. Charging system displays "fully charged" within one minute while vehicle dashboard shows 60% — clear battery management system malfunction. Vehicle has been undriveable and awaiting battery replacement for over a month at this point with no information on when the battery will arrive or be in stock. This is a known widespread defect in Ioniq 5 vehicles. Multiple owner reports document the same battery system failures, extensive reports of ICCU failures, and Hyundai's solution is to replace these failing components with the same component that fails repeatedly in other vehicles. No permanent fix or design change has been issued. This is a critical safety defect. Vehicle becomes completely immobile without warning — total loss of propulsion in traffic creates immediate crash and stranding risk. False charge readings mean the vehicle cannot be trusted to complete any trip safely. I have been left stranded multiple times on the turnpike of 80mph speed limit due to sudden total system failure. Hyundai has not resolved the root cause. They continue replacing batteries with the same defective system. This vehicle is fundamentally unsafe and unreliable. I should not be required to drive a vehicle with a battery system documented to fail catastrophically and repeatedly. Service records and repair invoices available upon request — vehicle currently at dealer awaiting battery replacement.

Upon entering vehicle in the morning of 12/30/25, a notable smell was first present. After turning on the vehicle, the car dashboard showed a "Check electric vehicle system" warning. The car was not able to be put into any gear besides neutral. Car was towed to dealership, and received word on 1/2/26 that an ICCU failure was the cause.Thankfully this occurred while parked in my garage, so was not in immediate danger. Perhaps this isn't a safety issue, but I am not sure what would have happened had the ICCU blown while driving so thought worth reporting.

Car gave an error check electrical system and went into limp mode on highway slowing to 25mph.

The ICCU on my Ioniq 5 failed about a year after getting the software update that supposedly addressed the issue. I am very concerned about the reliability of my car going forward as it doesn't appear Hyundai has addressed the issue and I have no reason to think the replacement ICCU component won't fail as well.

INCIDENT DESCRIPTION: On November 24, 2025, while driving at ~60 mph on NYS Route 17 (highway) with ~15% battery charge, my 2023 Hyundai IONIQ 5 suddenly entered limp mode and lost motive power. The high-voltage battery state of charge dropped instantly from ~10-15% to 0%, triggering error code P1B9600 (HV battery cell imbalance—cells failing to charge/discharge properly). I was unable to fully remove the vehicle from the roadway. My elderly mother was a passenger; a passing tractor-trailer came within 1 ft of striking us when disabled. NY State Police responded (report available). Required $300 tow to the Hyundai dealer, stranding us 150 miles from home.//PRIOR RELATED FAILURES: 1. November 14, 2025: Stranded due to ICCU failure (recall 24V-868 related) (stranded on NYS State Route 444). 2. September 15, 2025: Same P1B9600 code/limp mode/power loss; stranded in the middle of active travel lane of NYS 444; NY State Police report filed. 3. August 2025: Initial HV battery-related sudden power loss; stranded on Interstate 90 Eastbound (Erie, PA area). Despite repairs (September 2025 ICCU/"limp mode" software updates; October 2025 ICCU/high-voltage fuse replacement under recall 24V-868), defects persist. The vehicle charge rate also appears low and the battery consumption rate seems high.// CURRENT STATUS: Dealer (Vision Hyundai) confirmed high-voltage battery pack defective, requiring full replacement. Vehicle purchased new October 2024, under warranty. In service since mid-November 2025 (>30 days downtime). Provided loaner now, but prior rentals unreimbursed.//SAFETY RISK: Repeated sudden power losses create extreme highway crash risk, especially with vulnerable passengers. I am a licensed professional mechanical engineer, and can provide technical logs, repair orders, police reports upon request.The issues I have experienced appear to be linked to ongoing ICCU/HV system issues in IONIQ 5. I respectfully request expansion of the recall investigation.