As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER START ON RECALL GOT MASTER CAUTION, CONT CABIN ZONE TEMP. EXTINGUISHED WITH RESET. GROUNDED - YES. REMOVED AND REPLACED CONTROL CABIN TRIM MODULATING VALVE IAW B737-800 AMM 21-61-21-000-801 AND AMM 21-61-21-400-801, ETOPS GROUND FUNCTIONAL CHECK GOOD IAW AMM 21-61-00-740-801-002.