To provide a method for determining the rotor position of a polyphase switching reluctance machine comprising a rotor, a stator, and an energizable winding having more than one phase.

The ASCIC 57 in a controller 54 controls a switch 50 to inject a first diagnosis pulse of predetermined flux coupling into one phase winding, to inject a second diagnosis pulse of predetermined flux coupling into another phase winding substantially simultaneously with the first diagnosis pulse, to determine a first possible rotor position from the detected characteristics of the first pulse, to determine a second possible rotor position from the detected characteristics of the second pulse and to eliminate ambiguity of the rotor position by comparing the first and second possible rotor positions.