One problem related to turn signal switch has been reported for the 2012 Hyundai Sonata. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Hyundai Sonata based on all problems reported for the 2012 Sonata.
At night while driving if you use the turn signals or try to adjust your lights from dim to bright an electrical fault in the multifunction switch causes all of the lights in the vehicle inside and out to go out leaving you driving with no lights at all. This condition happened to me on a city street rule road the interstate it doesn't matter it happens if the car is moving or sitting still it's just an electrical problem that needs to be addressed.