As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FIRE INDICATION, TURNED OFF APU, THERE WERE NO INDICATIONS OF ACTUAL FIRE. SECURED THE APU RT INDUCTOR LOOP HARNESS. OPS CHECKED GOOD AND NO FAULTS FOUND ON MDC OR CAS. THE INDUCTOR LOOP IS NOT BELIEVED TO BE THE CAUSE OF THE FALSE FIRE WARNING. IT IS BELIEVED TO BE DUE TO THE FLIGHT PARAMETERS AND APU EXHAUST BLOW BACK CAUSING A FALSE FIRE WARNING.