NHTSA complaint #11752416

Owner complaint summary

The vehicle developed an intermittent but potentially dangerous engine control malfunction. After the engine reached normal operating temperature, the engine speed (RPM) would repeatedly surge while the vehicle was stopped in Park and Neutral, fluctuating from approximately 1,000 RPM to over 3,000 RPM without any throttle input from the driver. The condition occurred with the air conditioning turned off and could be reproduced multiple times. At approximately the same time, the Auto Start/Stop system stopped functioning and displayed a warning indicator. A malfunction indicator lamp (check engine light) also appeared during the incident. The warning light later turned off, but the engine surging continued. This unexpected increase in engine speed raises concerns about unintended vehicle movement or loss of driver control if the condition were to occur while shifting into gear or while driving. The unpredictable nature of the malfunction presents a potential safety risk to the occupants of the vehicle and to others on the road. The vehicle has been taken to an authorized Hyundai dealership for diagnosis and repair and remains under inspection. The problem is available for inspection. During my research, I found numerous reports from other Hyundai owners describing similar engine surging, idle fluctuation, and Auto Start/Stop malfunctions involving comparable vehicles. Because similar complaints appear to have been reported by multiple owners, I am submitting this report so the issue can be evaluated for a possible broader safety defect. I have videos of the incident