As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU EMERGENCY SHUTDOWN, APU FIRE LIGHT ON. NO SMOKE NOTED FROM OUTSIDE. NO SMOKE SEEN BY FLIGHT CREW. ACCOMPLISHED BITE TEST OF FIRE DETECTION AND APU EBU IAW AMM 26-13-00-710 AND 49-00-00-710 . NO FAULTS NOTED. RAN APU ALL OPS CHECKED OK.