As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT DECK TOO COLD, CANNOT MAKE WARMER IN AUTO MODE. OK IN MANUAL MODE. ACFT GROUNDED. PERFORMED BITE TEST OF PACK/ZONE TEMP CONTROLLERS IAW MM 21-51-00-700-803. THE CONTROLLER FAULTED THE CONTROL CABIN TRIM VALVE. REPLACED TRIM AIR MODULATING VALVE FOR THE CONTROL CABIN, REF MM 21-61-21-400-801. AGAIN PERFORMED BITE TEST OF PACK/ ZONE TEMP CONTROLLERS. NO FAULTS NOTED. GROUND VERIFICATION SUCCESSFUL.