As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT CABIN TEMP UNABLE TO CONTROL. ACFT GROUNDED. TROUBLESHOT IAW AMM 21-61, TASK 863. NO FAULTS FOUND ON LT OR RT PACK/ZONE TEMP CONTROLLERS. REPLACED TRIM AIR PRESSURE REGULATING AND SHUTOFF VALVE REF AMM 21-62-01-000-801 & 21-62-01-400-801.