As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THE ENVIRONMENTAL CONTROLLER WOULD NOT WORK IN AUTO MODE. THE MAINTENANCE TEAM TROUBLESHOT AND DETERMINED THE CABIN TEMP SENSOR FAN WAS DEFECTIVE. A NEW CONDITION FAN WAS INSTALLED. FUNCTIONAL CHECKS WERE SATISFACTORY AND THE AIRCRAFT WAS RETURNED TO SERVICE.