As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CREW REPORTING ISSUE WITH FLIGHT CONTROL. EMERGENCY WAS DECLARED AND ACFT LANDED WITHOUT FURTHER INCIDENT. IT WAS REPORTED THE CREW EXPERIENCED UNCOMMANDED RUDDER DEFLECTION WITH AP ENGAGED OR DISENGAGED AND WITH BOTH YD ON/OFF. NO EICAS RELATED MESSAGES APPARANT. THE ANOMALY OCCURED SEVERAL TIMES IN CRUISE AND ON DESCENT. YAW DAMPER FOUND FAILING. REPLACED.