As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN FWD AND AFT CABIN TEMP. CONTROLLERS WILL NOT STABILIZE CABIN TEMP IN AUTO WITH TRIM AIR SWITCH ON. FWD TEMP CONTROLLER SEEMS MOST AFFECTED, WITH TRIM AIR OFF POSITION THE CABIN IS CONTROLLABLE IN AUTO AS THE TEMP. IS AVERAGED THROUGHOUT THE CABIN. ACFT GROUNDED. PERFORMED PACK TEMP CONT. BITE REF FIM 21-62 TASK 801 NO FAULTS ON CONTROLLERS OPERATED BOTH PACK IN AUTO. BOTH SYSTEMS OPERATED NORMAL. GROUND VERIFICATION SUCCESSFUL.