What was found
ON TOUCHDOWN -60 KNOTS, AIRCRAFT WAS STEERING TO THE LEFT WITH NO TILLER OR RUDDER INPUT. RIGHT TILLER INPUT WAS UNRESPONSIVE, USED RUDDER TO CORRECT RIGHT WHEN NOSE WHEEL STEERING SUDDENLY STEERED A/C 30 DEGREE OFF RUNWAY CENTERLINE AND NOSE STEERING CAUTION ILLUMINATED. RAN THE CHECKLIST, TURNED NOSE STEERING OFF THEN ON, NOSE STEERING CAUTION EXTINGISHED AND NOSE STEERING AND TILLER WORKED FOR TAXI TO PARKING. REMOVED FROM SERVICE. INTERROGATED PCU FOUND FAULT CODE P-SW. REPLACED NOSE WHEEL STEERING MANIFOLD IAW AMM 32-51-16-000/400-801. OPS CHECKED GOOD IAW AMM 32-51-00710-801. NO FAULTS FOUND. RETURNED TO SERVICE.