As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER START, ON RECALL, CONT CAB MASTER CAUTION ZONE TEMP ILLUMINATED. EXTINGUISHED WHEN RESET, SUPPLY DUCT TEMP IS WORKING NORMAL. GROUNDED - YES. REMOVED & REPLACED VALVE, TRIM MODULATING IAW B737-800 AMM 21-61-21/401. OPS CK NORMAL.