As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK. FLIGHT CREW REPORTED A SHARP RT UNCOMMANDED RUDDER DEFLECTION WITH AUTO PILOT DISENGAGED. NO CHANGE IN FLIGHT PATH, YAW, ROLL OR PITCH ATTITUDE OCCURRED. DEGREE OF RUDDER DEFLECTION NOT REPORTED. AIRCRAFT RETURNED TO DEN WITHOUT INDICENT. MAINTENANCE REPLACED YAW DAMPER COUPLER AS PRECAUTIONARY. TROUBLESHOT YAW DAMPER SYSTEM PER MM 22-12-01. NO FAULTS STORED. PERFORMED BITE TEST. NO FAULTS NOTED. ALL ASSOCIATED SYSTEMS IN BITE TEST CHECKED NORMAL.