What was found
MAKING TURN ONTO RUNWAY, STEERING INOP AMBER CAS MESSAGE ILLUMINATED AND NOSE WHEEL WENT INTO CASTERING MODE. WE WERE ABLE TO CASTER NOSEWHEEL BACK AND TAXI FORWARD TO CLEAR RUNWAY. NOSE STEER SWITCH CYCLED AND WAS ABLE TO REINSTATE STEERING. TAXIED NORMALLY BACK TO RAMP TO INTIATE CALL TO FODM. WHEN BACK IN THE RAMP AREA I TURNED OFF NOSE STEER IN ANTICIPATION OF A AFTER START FLOW IF ANOTHER TAKEOFF WAS TO BE ATTEMPTED. WHILE ON CALL TO FODM I TURNED NOSE STEER BACK ON AND IMMEDIATELY RECEIVED A STEERING INOP AMBER CAS AGAIN. CORRECTIVE ACTION: NO FAULTS FOUND IN MDC. PERFORMED SEVERAL OPERATIONAL CHECKS OF NWS WITH NO FAULTS NOTED REFERENCE WITH CL-650 AMM 32-51-00.MCC VERIFIED WITH NO HISTORY THIS IS SATISFACTORY.