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 ILLUMINATES ON RECALL. EXTINGUISHES W/ MASTER CAUTION RESET. GROUNDED - YES. VERIFIED CONT CAB ZONE TEMP LIGHT ILLUMINATES ON RECALL. PERFORMED PACK/ZONE TEMP CONTROLLER BITE TEST REF B737-900 AMM 21-61-00. FOUND FLT DECK TRIM VALVE FAULT DURING BITE TEST. REMOVED AND REPLACED CONTROL COMPARTMENT ZONE TEMP CONTROL TRIM AR MODULATING VALVE REF AMM 21-61-21. OPS CHK GOOD.