As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#2 TEMP CONTROLLER FAULTS ZONE TRIM VALVE. GROUNDED - YES. PERFORMED FIM 21-62 TASK 834. ALL WIRING CHECKS COMPLETE AND NO DISCREPANCIES NOTED. REPLACED ZONE TEMP CONTROLLER 2 REF AMM 21-61-20. INSTALLATION TEST PASSED. VERIFIED GREEN GO LIGHT ILLUMINATES WITH NO RED LIGHTS.