As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RECEIVED CABIN ALT CAUTION MESSAGE ON CLIMB-OUT; COULD NOT PRESSURIZE AIRCRAFT IN AUTO OR MANUAL PRESSURIZATION MODES. AIRCRAFT REMOVED FROM SERVICE. INSPECTED PAX DOOR SEAL AND CLEANED DEBRIS, NO OTHER DEFECTS NOTED, REF. AMM 52-11-00 PRESSURIZED A/C WITH APU, REF AMM 21-31-00, PRESSURIZATION OKAY.