As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS DURING APPROACH, GOT 3 APU FIREX FAIL CAUTION MESSAGES CLEARED BY ITS SELF EACH TIME. MAINTENANCE ACCOMPLISHED FIM TASK 26-22-00-810-803-A. REMOVED AND REPLACED APU FIRE BOTTLE IAW 26-22-01-000/400-801-A. OPS CHECK GOOD.