As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUTOPILOT "A" WILL NOT ENGAGE. GROUNDED - YES. PERFORMED B737-900 FIM 22-11 TASK 801 TEST GROUP 10. FAULT MESSAGE 22-11254 DISPLAYED. REMOVED AND REPLACED DFCS MODE CONTROL PANEL REF B737-900 AMM 22-11-34. ACCOMPLISHED LRU REPLACEMENT TEST FOR MCP (BITE TEST GROUP #32) REF AMM 22-11-34. ALL TEST PASS. ACCOMPLISHED LAND VERIFY TEST REF AMM 22-11-00. ALL TEST PASS.