What was found
PHX - FLT 440 - UNCOMMANDED RUDDER MOVEMENT (SECOND OCCURRENCE), DURING TAKEOFF ROLL JUST PRIOR TO V1 (139 KTS), A SHARP MOMENTARY YAW LEFT OCCURRED. YAW DAMPENER WAS NOT TURNED ON. TAKEOFF CONTINUED, FLIGHT AND LANDING WERE UNEVENTFUL. AS A PRECAUTION, MAINTENANCE REPLACED RUDDER PCU. OPS CHECK PERFORMED PER AWA TASK CARD F6B27003. AUTOPILOT AND YAW DAMPENER SYSTEM CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. (M)