As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT LGA, CREW REPORTED LEFT PACK OUTPUT TEMPERATURE REACHED 120° C IN AUTO MODE. AT THE SAME TIME, SMOKE WAS SEEN BILLOWING FROM AFT EQUIPMENT BAY AND STRANGE SMELL (BURNING) NOTED IN CABIN. MAINTENANCE INSPECTED, REMOVED AND REPLACED LEFT ACM AND PERFORMED CHECKS USING AIRCRAFT MAINTENANCE MANUALS. AIRCRAFT RELEASED FOR SERVICE.