NHTSA Complaint #11710941 — 2018 HYUNDAI TUCSON

The engine and engine management system of my 2018 Hyundai Tucson experienced repeated failures resulting in loss of propulsion and unsafe drivability. In November 2025, while traveling approximately 75 mph on a freeway, the vehicle suddenly entered limp mode without any prior warning, causing an abrupt loss of power in active highway traffic. No warning lamps or messages appeared before the failure. After the loss of propulsion occurred, the check engine light, battery light, and oil light illuminated sequentially. Diagnostic trouble codes P1326 and P0326 were recorded. Initial inspection indicated severe oil consumption despite a recent oil change less than 2,000 miles earlier. A Hyundai dealership replaced knock sensors under warranty. Shortly after release (30 miles), the vehicle again exhibited severe drivability issues, including a flashing check engine light, and required immediate towing. A second Hyundai dealership replaced the short engine block under warranty. Approximately 180 miles after the engine replacement, the vehicle again developed unsafe drivability symptoms, including delayed throttle response, failure to accelerate unless the accelerator was fully depressed multiple times, jerking or lugging when slowing or stopped, and a faint whining noise. The check engine light illuminated again. These failures represent repeated loss of propulsion and unsafe operation following manufacturer-approved repairs, including full engine replacement. The vehicle has been out of service for approximately 57 days and remains in the custody of a Hyundai dealership awaiting diagnostics. The vehicle is available for inspection upon request. The sudden and unpredictable loss of power at highway speed created a significant risk of collision and serious injury to the driver and surrounding motorists.