A new class-action lawsuit accuses Hyundai and Kia of selling electric vehicles with a defective integrated charging control unit (ICCU) that can cause the vehicle’s 12-volt battery and the ICCU itself to fail, leading to reduced or complete loss of drive power, according to attorneys at Hagens Berman.

The lawsuit was filed Sept. 23, 2026, in the U.S. District Court for the Western District of Washington and states both automakers knew about the ICCU failures before issuing recalls, and that neither of the two recall remedies have fixed the problem.

The following model year vehicles are affected by the alleged defect: 2022-2024 Hyundai Ioniq 5, 2023-2025 Hyundai Ioniq 6, 2023-2025 Hyundai Ioniq 9, 2022-2024 Kia EV6, 2024 Kia EV9, 2023-2025 Genesis GV60, 2023-2025 Genesis GV70 Electrified and 2023-2024 Genesis GV80 and GV80 Electrified. If you own or lease an affected Hyundai, Kia or Genesis EV, contact us to learn more about the lawsuit and your rights. Hagens Berman plans to expand the case to cover additional states as affected consumers continue to reach out for assistance.

The lawsuit states that the ICCU converts power from the vehicle’s high-voltage battery to charge its 12-volt battery, which powers vehicle startup, parts of the braking system and other essential functions. According to the lawsuit, when the ICCU or its associated high-voltage fuse fails, the 12-volt battery stops receiving charge — and as it drains, the vehicle can display multiple warnings, lose power in stages and shut down entirely, including while in operation.

“Hyundai and Kia have now recalled these vehicles twice, and owners are still telling us their cars quit on them,” said Steve Berman, managing partner and co-founder of Hagens Berman. “Replacing a defective part with another copy of the same defective part is not a fix. Our clients paid for reliable transportation and instead they’re left waiting months for backordered parts, only to have the problem return.”

Hundreds of Incidents Prior to Recalls

Hyundai and Kia each recalled affected vehicles in March 2024 and again in November 2024. The second round of recalls expressly replaced the first recall and required owners and lessors to return vehicles that had already been repaired to the dealership for a new remedy, according to the complaint. Owners report repeat failures even after software updates, replacement 12-volt batteries and complete ICCU replacements.

According to the lawsuit, Hyundai and Kia knew about ICCU failures well before those recalls. Hyundai confirmed 618 unique incidents in the United States reported between March 2022 and March 2024, before it announced the first recall in March 2024. The complaint alleges Hyundai possessed information concerning ICCU failures by at least October 2022, when returned ICCU components were being analyzed and heat damage was observed inside the units.

Federal regulators opened investigations into ICCU failures in both automakers’ vehicles in mid-2023, according to the lawsuit. In a September 2023 joint demonstration involving Hyundai and the National Highway Traffic Safety Administration (NHTSA) personnel, a test vehicle stalled completely after roughly 21 to 26 minutes of operation under harsh conditions.

The lawsuit seeks to recover owners’ and lessees’ financial losses, including overpayment at purchase or lease, repair, rental car, towing and gas costs and loss of use. Attorneys also seek injunctive relief that could include an order requiring Hyundai and Kia to provide a repair that adequately remedies the alleged defect.

The suit’s named plaintiffs purchased a 2023 Hyundai Ioniq 5 and expected a safe and reliable vehicle, the lawsuit states. Over roughly 14 months, his vehicle received multiple charging-related software updates, at least two replacement 12-volt batteries and at least two replacement ICCUs — and still failed. On one occasion, the complaint states, the plaintiffs had just finished charging the vehicle. It then began beeping, warned them to pull over immediately, failed to shift gears and shut down, leaving them unable to open the trunk. The vehicle had to be towed. During one repair their vehicle sat at the dealership for nearly two months, and during another they received a loaner vehicle for 33 days because the replacement ICCU was on backorder.

Hagens Berman has brought many class-action lawsuits against automakers over safety defects and has helped secure some of the largest automotive settlements in history. The firm previously secured settlement relief valued at up to $1.3 billion for owners of Hyundai and Kia vehicles equipped with the Theta II GDI engine, which were vulnerable to engine failure and fire.

Learn more about the class-action lawsuit against Hyundai, Kia and Genesis over the ICCU failure.

About Hagens Berman

Hagens Berman is a global plaintiffs’ rights complex litigation law firm with a tenacious drive for achieving real results for those harmed by corporate negligence and fraud. Since its founding in 1993, the firm’s determination has earned it numerous national accolades, awards and titles of “Most Feared Plaintiff’s Firm,” MVPs and Trailblazers of class-action law. More about the law firm and its successes can be found at hbsslaw.com. Follow the firm for updates and news at @ClassActionLaw.

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