An electronic control unit includes a processor performing a process necessary for a charging control based on a pilot signal, an input circuit disposed in a stage preceding an input port of the processor, and a pseudo-signal supply circuit supplying a pseudo-pilot signal to a pilot signal line under the control of the processor, and the processor performs a malfunction diagnosis for the input circuit based on a signal state of the input port when controlling the pseudo-signal supply circuit to supply the pseudo-pilot signal to the pilot signal line.