As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: CABIN PRESSURE SYSTEM 2 FAULT AFTER TAKE OFF AMBER SYSTEM NUMBER 2 ON ELECTRONIC CENTRALIZED AIRCRAFT MONITOR PRESSURE PAGE. SYSTEM NUMBER 1 GREEN BUT OUTFLOW VALVE APPEARED STUCK. UNABLE TO PRESSURIZE THE AIRCRAFT EVEN IN MANUAL MODE. FLIGHT DIVERTED TO LAX FLIGHT DID NOR DECLARE EMERGENCY AND WAS NOT OVERWEIGHT FOR LANDING. REMOVED ND REPLACED OUTFLOW ELECTRONIC MODULE 10HL1-A (AALA202109201661). ALSO REMOVED AND REPLACED CABIN PRESSURE CONTROLLER.