As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CONT CAB ZONE TEMP ON AFTERSTART RECALL. EXTINGUISHES ON RESET. GROUNDED - YES. REMOVED AND REPLACED CONT CAB TRIM AIR MODULATING VALVE V143 REF B737-800 AMM 21-61-21. RAN BOTH PACKS AT VARYING TEMPS, OPS NORMAL, PZTC BITE PASSED. ETOPS GROUND VERIFICATION SUCCESSFUL.