A control apparatus includes a lower layer control unit configured to perform control of a load, an upper layer control unit configured to control the lower layer control unit, a communication unit configured to perform communication between the upper layer control unit and the lower layer control unit via a communication line, a detection unit configured to detect power supply voltage of the lower layer control unit, wherein the upper layer control unit detects communication abnormality of the communication unit and notifies the communication abnormality, the upper layer control unit notifying abnormality of power supply voltage of the lower layer control unit, in such a manner as to be identified from the communication abnormality of the communication unit.