As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RECEIVED A NR 2 A/C PACK VALVE CLOSED MESSAGE. FOLLOWED QUICK REF HANDBOOK AND DESCENDED TO 10,000 FT. ELECTED TO RETURN TO FIELD AND LANDED WITHOUT INCIDENT. BLEED AIR DUCT AND DUAL TEMP CONTROL VALVE REPLACED. OPS CHECKED GOOD WITH NO FURTHER DEFECTS NOTED.