To provide a controller and a control method for a motor equipped with a plurality of energization systems each including a coil set of coils corresponding to a plurality of phases and an inverter for outputting a current to each of the phases in the coil set. The controller stops the inverter of a first energization system if the total phase current in the first energization system is an outlier. During a predetermined period after stopping the inverter of the first energization system, even if the total phase current in any other energization system is an outlier, the controller continues to operate the inverter of the other energization system. This makes it possible to continue to operate the inverter of a normal energization system as required as possible while stopping the inverter of an energization system having an abnormality such as a short-circuit or short-to-ground.