As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CONTROL CABIN TEMP HARD TO CONTROL. LEFT PACK TEMP INDICATES 80 DEG C. ACFT GROUNDED. FOUND LEFT PACK TEMP CONTROL VALVE V00139 STUCK IN OPEN POSITION. REMOVED AND REPLACED LEFT PACK TEMP CONTROL VALVE IAW AMM 21-61-21-000-801, AND 21-61-21-400-801. LEAK CHECKED GOOD. PERFORMED A LT PACK TEMP CONTROL BITE CHECK IAW AMM 21-61-00-700-806-002. BITE CHECK PASSED.