As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ACFT WENT INTO AN UNCOMMANDED RIGHT TURN. NOTICED IT HAD GONE INTO HDG MODE AND THE HDG WAS APPROX 112 DEGREES (VS. 030) F/O DISCONNECTED AUTOPILOT AND BANKS 30 LEFT TO REJOIN COURSE. INTERROGATED MAT AND FOUND MAINT MESSAGE 22-11635 NOT ACTIVE. FIM 34-31-00-810-875, R & R RT MMR M34510 IAW AMM 34-31-01-4. ALL TESTS PASSED. ALSO COMPLETED ADFS SYS TEST IAW AMM 22-11-00-5 WITH NO FAULTS NOTED. ACFT OK FOR SERVICE.