Hyundai, Kia EV defect triggers wave of lemon law lawsuits

Complaints over the Hyundai and Kia EV ICCU defect are mounting as owners report charging failures and sudden power loss while driving, raising safety concerns and triggering lawsuits under the lemon law.

According to a recent reliability survey by Consumer Reports covering more than 380,000 vehicles, owners of several Hyundai and Kia electric models repeatedly reported an inability to charge, loss of propulsion during driving and various electrical system malfunctions.

The issue affects models that share the same electric vehicle platform. These include the Hyundai Ioniq 5, Ioniq 6, Ioniq 9, Kia Niro EV, EV6, EV9, and Genesis GV60.

Survey data showed that between 2% and 10% of owners, depending on model and year, reported ICCU-related problems. By comparison, charging-related issues in other 2023–2025 electric vehicles typically occurred at rates below 1%. In some cases, the reported rate was up to 10 times higher.

The ICCU, or Integrated Charging Control Unit, converts high-voltage battery power into low voltage to operate essential vehicle systems. It also charges the 12-volt battery that powers headlights and other electrical components. When the ICCU fails, the battery can discharge, and the vehicle may stop operating while in motion.

Corbin, who runs the YouTube channel The Ioniq Guy and manages related Facebook communities, said he has heard repeated accounts from owners. He stated that some drivers experienced recurring failures even after software updates. In addition, some relatively new vehicles reportedly developed the same issue. He said a few owners replaced the ICCU three times within several years.

Industry sources have cited potential causes such as overheating of MOSFET transistors that regulate electrical current, resulting in blown fuses or high-voltage surge loads. However, manufacturers have not publicly confirmed a definitive root cause or permanent solution.

Meanwhile, lemon law lawsuits are increasing. Owners allege repeated breakdowns tied to the ICCU defect and are seeking refunds.

Attorney Daeyong Jung, who specializes in lemon law cases, said electric vehicles can experience various power control issues by design. However, he noted that ICCU-related complaints appear especially frequent among Hyundai and Kia EV models. He said some drivers reported pressing the accelerator without gaining speed. Others described vehicles shutting off during operation. Although no major accidents have been reported, he said the situations were potentially dangerous.

Industry sources said dealerships sometimes lack the technical capacity to identify the precise cause. In some cases, vehicles were repaired but experienced the same failure again. Some owners reportedly waited more than a month to retrieve their vehicles from dealerships. Consumer Reports noted that parts shortages delayed repairs for weeks or even more than two months in certain cases.

Under lemon law, a vehicle may qualify if a safety-related defect recurs after two repair attempts. It may also qualify if repairs extend beyond 30 days. Attorney Jung said repeated propulsion loss or other safety-related failures could meet the threshold.

The ICCU issue highlights the risks of shared platform strategies. Hyundai Motor Group uses common components across its E-GMP-based electric vehicles to improve efficiency and reduce costs. As a result, a defect in one component can affect multiple brands and models simultaneously.

Some affected vehicles are undergoing recall repairs. Hyundai said it plans to expand parts supply and provide reimbursement for certain costs. Kia said replacement ICCUs and fuses have been secured at logistics centers and are being supplied to dealerships.

BY HOOSIK WOO   [woo.hoonsik@koreadaily.com]