NHTSA Complaint #11705351 — 2016 HYUNDAI SONATA

On November 10, 2025, my 2016 Hyundai Sonata Hybrid (VIN [XXX] , approximately 150,000 miles) experienced a sudden loss of power while I was turning right and accelerating into traffic. The vehicle immediately entered limp mode with flashing warning lights and audible alerts. The vehicle lost normal propulsion and could not accelerate properly, creating a dangerous situation as it was blocking a traffic lane. I was forced to limp the vehicle into a nearby parking lot to get out of traffic. The vehicle was not safely drivable afterward and was towed home. A few days later, the vehicle was towed to Murdoch Hyundai in Lindon, Utah, for diagnosis. The vehicle was found to have diagnostic trouble code P1326, which Hyundai identifies as activation of the Knock Sensor Detection System (KSDS) related to connecting-rod bearing wear. This condition is part of Hyundai’s known engine defect and safety recall/warranty extension programs. During inspection, the dealer observed that the valvetrain did not show signs of neglect or sludge, which is inconsistent with oil starvation or severe maintenance neglect. This further supports that the failure is consistent with the known connecting-rod bearing defect addressed by Hyundai’s KSDS safety recall, rather than a maintenance-related issue. This is a safety issue because sudden loss of propulsion or reduced power while entering traffic creates a high risk of collision. Hyundai customer care has been unwilling to open a new case number or escalate review, and the dealer has indicated possible denial of engine replacement coverage based on incomplete oil-change records, despite the vehicle exhibiting the KSDS safety condition. I am requesting NHTSA review of this safety-related defect and the manufacturer’s handling of KSDS/P1326 failures. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)