As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL 340 DURING CRUISE, A SINGLE AUTOPILOT DISCONNECT HAPPENED ON CMD "A". AUTOPILOT WAS RE-EMGAGED PM "A" SIDE AND DID NOT OCCUR AGAIN. GROUNDED - YES. ACCOMPLISHED B737-900 FIM 22-11 TASK 801. DFCS BITE FOUND MSG 22-11208 AND 22-11607 IN LEG 1 HISTORY. COMPLETED LRU TESTS 20.00 AND 20.32. ALL TESTS PASS. NO CURRENT FAULTS. INTERMITTENT FAULT. AUTOPILOT OK FOR SERVICE.