As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT LOST PRESSURIZATION DURING DECENT. CREW PERFORMED EMERGENCY LANDING. NO FURTHER INCIDENT ON LANDING. PERFORMED GROUND CHECKS OF PRESSURIZATION SYSTEM. COULD NOT DUPLICATE PROBLEM. FURTHER TROUBLESHOOTING REVILED INTERMITTENT FAULT IN DIFFERENTIAL RELIEF VALVE OPENING EARLY. REMOVED AND REPLACED DIFFERENTIAL RELIEF VALVE. PERFORMED FUNCTIONAL CHECKS OF PRESSURIZATION SYSTEM. ALL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.