As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUTOPILOT A IS INOP TRIED TO ENGAGE SEVERAL TIMES AND IT KICKS OFF. GROUNDED - YES. REMOVED AND REPLACED AUTOPILOT AILERON ACTUATOR A PER B737-900 AMM 22-11-25-000-801 / AMM 22-11-25-400-801. ACCOMPLISHED AUTOPILOT AILERON ACTUATOR ADJUSTMENT PER AMM 22-11-25-820-801 AND PERFORMED AUTOPILOT AILERON ACTUATOR TEST (DFCS LIBRARY TEST #31) PER AMM 22-11-25-710-801 - ALL TESTS PASS, NO LEAKS NOTED.