As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAXI OUT, CREW RECEIVED AN APU/ENGINE FIRE FAIL MESSAGE FOLLOWED BY AN LEFT ENGINE AND APU FIRE INDICATION. UPON INVESTIGATION FALSE INDICATION WAS CAUSED BY FAULTY FIRE DETECTION WARNING CONTROL UNIT. UNIT WAS REMOVED AND REPLACED AND FUNCTIONALLY CHECK GOOD. (M)