A lighting control apparatus for a vehicle is provided which works to diagnose a malfunction of a light source which includes a plurality of lighting devices such as LEDs and emits light outside the vehicle. The lighting control apparatus determines a state of the vehicle. When the light source is determined to be malfunctioning, the lighting control apparatus operates the light source in one of predetermined warning lighting modes which is selected based on the state of the vehicle. This attracts a vehicle user's attention to the malfunctioning light source.