Headlight control device and lamp driver

A headlight control device configured to control a headlight of a vehicle, the headlight control device comprising:

• a first processor configured to provide an instruction to turn on and turn off the headlight;
• and
• a second processor configured to turn on or turn off the headlight in accordance with the instruction of the first processor, wherein:
• the first processor is configured to
• detect whether the vehicle is in a traveling state or a stopped state as a vehicle state, and
• output, to the second processor, a lamp instruction signal to turn on or turn off the headlight, and a traveling state signal or a stopped state signal as a vehicle state signal corresponding to the vehicle state;
• and
• the second processor is configured to
• diagnose a communication state with the first processor,
• acquire the lamp instruction signal and the vehicle state signal that are output from the first processor,
• execute control to turn on or turn off the headlight in accordance with the acquired lamp instruction signal, and
• determine whether communication with the first processor is interrupted due to an abnormality based on the diagnosed communication state with the first processor and the acquired vehicle state signal.