As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FIRE WARNING. *S/D* INSPECTED APU, FOUND NO EVIDENCE OF FIRE. CHECKED LOOPS, CONNECTORS AND OHMED OUT. FOUND NO SHORTS OR OPENS. FOUND OIL ON CONNECTOR AND CLEANED. REPLACED FIRE DETECTION UNIT AS A PRECAUTION. REPLACED FIRE BOTTLE AND SQUIB. RAN APU, OPERATION NORMAL.