As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CONTROL CAB ZONE TEMP LIGHT EXTINGUISH ON RECALL. GROUNDED - YES. CONTROLLER BITE HAD HARD FAULT CALLING OUT CONTROL CABIN TRIM MODULATING VALVE. WOULDN'T RESET. REMOVED AND REPLACED CONTROL CABIN MODULATING VALVE IAW B737-800 AMM 21-61-21-000-801 AND AMM 21-61-21-400-801, ETOPS GROUND FUNCTIONAL CHECK OPS CHECK GOOD IAW AMM. 21-61-00-700-806-002.