What was found
AUTOPILOT 'A' INOP, DISENGAGES AFTER A FEW SECONDS. GROUNDED-YES. PERFORMED DFCS BITE, PER B737-900 FIM 22-11 TASK 801. FAULT HISTORY, A CHANNEL HAS 2 FAULTS 22-11189 AIL SYNC INV >4 SEC AND 22-11147 AIL PRESS SW-1. REMOVED AND REPLACED AUTO PILOT AILERON ACTUATOR `A` PRESSURE SWITCH, REF B737-900 AMM 22-11-40. OPS TEST NML. IN ADDITION, ACCOMPLISHED DFCS ALL LIBRARY TESTS, REF AMM 22-11-00/501, ALL TESTS PASSED.