As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PRESSURIZATION WAS UNCONTROLLABLE IN AUTO AND MAN MODES. CORRECTIVE ACTION: REMOVED AND REPLACED RAM AIR SHUT OFF VALVE IN REFERENCE TO AMM 21-52-10. PRESSURIZED AIRCRAFT. NO PROBLEMS NOTED. OPS CHECK GOOD AT THIS TIME. (TC# 20190612008)