As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EXPERIENCED CABIN ALTITUDE CLIMBING ENROUTE TO FL 430. REQUESTED DESCENT AND DIVERTED TO UNSCHEDULED LANDING. TROUBLESHOT PROBLEM AND FOUND DEFECTIVE PRIMARY OUTFLOW VALVE, INTERMITTENT CONTROL SOLENOID. REPLACED PRIMARY OUTFLOW VALVE WITH OVERHAULED UNIT PART 52771-316, SERIAL NUMBER 1086. PERFORMED CHECK FLIGHT TO FL430 TO CHECK ALL PARAMETERS OF PRESSURIZATION CONTROL SYSTEM IN ACCORDANCE WITH AIRCRAFT OPERATION AND MAINTENANCE MANUAL PROCEDURES. NO DEFECTS NOTED AT THIS TIME.