As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CONTROL CABIN TEMP, ILLUMINATED ON MASTER CAUTION RECALL, ABLE TO RESET ON MASTER CAUTION RESET. GROUNDED - YES. ON INITIAL EVALUATION FOUND THE RED FAULT LIGHT ON THE RH PACK ZONE/TEMP CONTROLLER FOR FLIGHT DECK TRIM VALVE. ACCOMPLISHED THE RESET PROCEDURE AND THE GREEN GO LIGHT CAME ON. NO FURTHER ACTION NECESSARY. ETOPS GROUND VERIFICATION TEST SUCCESSFUL, REF B737-800 FIM 21-62 TASK 832.