A loss of exterior lighting can reduce the driver's visibility and the visibility of the vehicle to other drivers, increasing the risk of a crash.
The Light Driver Control Module B (LDCMB) may fail, preventing the turn signals, daytime running lights, low beam, and high beam headlights from illuminating. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, "Lamps, Reflective Devices, and Associated Equipment."
What to do: Book it in at your next service. There is no deadline and no charge.