One problem related to headlight switch has been reported for the 2013 Hyundai Sonata. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2013 Hyundai Sonata based on all problems reported for the 2013 Sonata.
The bulbs on my vehicle as well as several others Sonata's of the same model are having electrical failure when the lights are switched from off to on while driving . This causes the car to decelerate . I've also noticed electrical issues with bulbs for the brake lights and headlights at various speeds as well. For example , when it begins to rain if you turn on the lights in compliance with the state law, the car loses power and decelerates.