As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED, THE LT PACK TEMP TO BE 113 DEG C AND UNCONTROLLABLE IN AUTO OR MANUAL. CREW ELECTED TO RETURN TO DTW LANDING WITHOUT INCIDENT. MAINTENANCE INSPECTED THE AIRCRAFT AND REMOVED AND REPLACED THE LT AIR CYCLE MACHINE. CHECKS WERE ACCOMPLISHED WITH NO DEFECTS AND THE AIRCRAFT WAS RELEASED FOR SERVICE. (A)