As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE AUTO FUNCTION OF THE CABIN PRESS CONTROL FAILED. TROUBLESHOOTING USING THE FAULT ISOLATION MANUAL & BITE TESTS FOUND A FAULT ON THE OUTFLOW VLV. THE OUTFLOW VLV WAS REPLACED & FAULTS DID NOT RETURN. OPERATIONAL TESTS OF THE CABIN PRESS CONTROL SYS WERE NORMAL.