As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT CAB ZONE TEMP LIGHT ON MASTER CAUTION RECALL. GROUNDED-YES. PERFORMED B737-900 FIM 21-62 TSK 801, FOUND AFT ZONE TRIM FAULT. PERFORMED FIM 21-62 TSK 835. REPLACED TRIM AIR MODULATING VALVE (AFT PAX COMPARTMENT), PER B737-900 AMM 21-61-21. LEAK AND OPERATIONS CHECK GOOD. ETOPS GROUND VERIFICATION GOOD.