As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FIRE WARNING MESSAGE IMMEDIATELY AFTER LANDING. APU AUTO SHUTDOWN AND BLEW FIRE BOTTLE. FIRE WARNING WENT AWAY IMMEDIATELY. (FLIGHT #4039 FILED CLOSED) THIS DISCREPANCY WAS TRANSFERRED TO CAMP ITEM 25172039 WITH THE FOLLOWING CORRECTIVE ACTION: "REMOVED AND REPLACED APU FIRE BOTTLE IN REF WITH CRJ900 AMM 26-22-07"