What was found
AP #1 (AUTOPILOT A) DISENGAGED TWICE WHILE AT CRUISE (FL350) WITHOUT ANY PILOT INPUT OF ANY KIND. THERE WAS NO TURBULENCE WHEN THE DISCONNECT OCCURRED. GROUNDED - YES. PERFORMED DFCS BITE AND FOUND NO CURRENT FAULTS PER B737-900 FIM 22-11 TASK 801. FOUND DIFFERENT FAULT CODES IN FAULT HISTORY. RAN LRU TESTS FOR THOSE AND ALL TESTS PASSED. PERFORMED AUTOPILOT GROUP 11 TESTS AND ALL TESTS PASSED FOR BOTH CHANNELS. PERFORMED FIM 22-12 TASK 813 FOR MESSAGE 22-11145. NO FAULTS FOUND. COULD NOT DUPLICATE PROBLEM.