As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CONT CAB ZONE TEMP LIGHT ON RECALL. GROUNDED - YES. PERFORMED BITE CHECK OF PACK/ZONE TEMP CONTROLLER REF B737-900 AMM 21-61-00-700-806-002, FOUND FAULT FLT DECK TRIM VALVE. REMOVED AND REPLACED CONT TRIM VALVE REF AMM 21-61-21-000-801 AND 21-61-21-400-801, OPS CHECK GOOD NO LEAKS NOTED.