A control apparatus controlling a motor for driving an object to switch a shift range of a transmission includes: switching devices for energization to windings of the motor; a controller for the switching devices; a current detecting circuit for a current in the windings and the switching device; a current limit circuit keeping an average of the current within a predetermined range; a standard position learning device of the motor at a learning range such that the current limit circuit limits the current, and the motor rotates until the object stops at a limit position of a movable range; a shift range determination device; and an error determination device determining that the current detecting circuit or the current limit circuit malfunctions when the object does not reach the limit position, the shift range is in a non-learning range, and the standard position learning device starts to learn the standard position.