As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED LOSS OF CABIN PRESSURIZATION DURING FLIGHT AND DIVERTED TO LAND. MX TROUBLESHOOTING AND GROUND ENGINE RUNS COULD NOT DUPLICATE PROBLEM. SUBSEQUENT TEST FLIGHT DUPLICATED DISCREPANCY. PROBLEM IDENTIFIED AS A WEAK OR INTERMITTENT CABIN PRESSURIZATION FLOW CONTROL VALVE (PN 3200335-2). PART REPLACED AND ACFT RETURNED TO SERVICE. (K)