As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CONTROL CAB ZONE TEMP CAUTION ILLUMINATED UPON RECALL. GROUNDED - YES. ACCOMPLISHED PACK/ZONE TEMP CONTROLLER BITE, #2 PZTC FLIGHT DECK TRIM VALVE LIGHT ILLUMINATED ON BIT AND PREVIOUS FLIGHT, BUT NOT VERIFY PHASE OF TEST. OPERATED BOTH PACKS, ABLE TO ADJUST FLIGHT DECK TEMPERATURE, ZONE TEMP LIGHT DID NOT ILLUMINATE. REPEATED PACK /ZONE TEMP CONTROLLER BITE WITH NO FAULTS NOTED. REF B737-900 AMM 21-61-00. ETOPS SIGNIFICANT SYSTEM GROUND VERIFICATION SUCCESSFUL.