As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE AUTO PRESSURIZATION FUNCTION WAS ERRATIC WHILE THE MANUAL PRESSURIZATION FUNCTION WAS ALREADY DEFERRED. THE CREW RETURNED TO FIELD & LANDED WITHOUT INCIDENT. MX REPLACED THE TUBING FROM THE PRESS CHECK VLVS TO THE VACUUM VENTURI. OPERATIONS CHECKED GOOD WITH NO FURTHER DEFECTS NOTED.