As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ITEM-1 SUBTLE YET NOTICEABLE UNCOMMANDED RIGHT YAW DURING FLIGHT W/AUTO PILOT ON. AILERONS TRIED TO CORRECT. NO ENGINE TROUBLE. FELT AS THOUGH RUDDER WAS BEING PRESSED. FLT CONTROL SYNOPTIC PAGE REVEALED NOTHING ABNORMAL. CAUTION DISAPPEARED WHEN AUTO PILOT WAS TURNED OFF. ITEM-2. YD2 INOP STATUS MSG CAME ON (WHILE TAXIING IN) ON GROUND. ISSUED MEL 22-11.