In a control apparatus including a drive unit, first and second power supplies, a first diode, first and second control units, and a control method of the control apparatus, the first diode is connected to first and second power lines such that a direction from the second power line to the first power line is set as a forward direction, the second control unit is configured to calculate correction information for a first state value based on the voltage of the first power line before and after an abnormality has occurred in the first power supply and to transmit the correction information to the first control unit when the abnormality has occurred in the first power supply, and the first control unit is configured to correct the first state value using the correction information when the correction information has been received from the second control unit.