As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ABOUT ONE HOUR INTO CRUISE AT FL 320, AUTOPILOT B ENGAGED, THE AUTOPILOT DISCONNECTED WITHOUT CAUSE. DID NO RECUR AFTER ENGAGED. ACFT GROUNDED. ACCOMPLISHED FLIGHT FAULT REVIEW. ACCOMPLISHED TEST IAW 22-11-34-501 BITE GROUP 32, TEST PASSED. HGS TEST OK, REF 34-36-00.