What was found
"B" AUTOPILOT WILL NOT ENGAGE A CRUISE. GROUNDED - YES. DFCS FAULT REVIEW SHOWED FAULT 22-11149 "AIL PRESS SW-2" AND DFCS LIBRARY TEST #31 SHOWED CONSISTENT FAIL WITH FAULT 22-11144 "AIL DETENT SOLENOID-2". REMOVED AND REPLACED AUTOPILOT B AILERON ACTUATOR PER B737-900 AMM 22-11-25-000-801/AMM 22-11-25-400-801. REMOVED AND REPLACED AILERON ACTUATOR B PRESSURE SWITCH PER AMM 22-11-40-000-801/AMM 22-11-40-400-801. ACCOMPLISHED AILERON ACTUATOR ADJUSTMENT PER AMM 22-11-25-820-801 AND DFCS LIBRARY TEST #31 PER AMM 22-11-25-710-801 - ALL TESTS PASS.