POWER SUPPLY CONTROL DEVICE, IN-VEHICLE CONTROL DEVICE, AND POWER SUPPLY CONTROL METHOD

An individual ECU controls power supply through a wire W. A microcomputer of the individual ECU increases an average value of a wire current value of a current flowing through the wire W in a stepwise manner. The microcomputer determines, every time that the average value of a wire current value is increased, whether or not an anomaly has occurred in power supply through the wire (W) based on a temperature difference between a wire temperature of the wire (W) and an environmental temperature in an area surrounding the wire (W).