As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DIVERTED UNDER AMBER ALERT DUE TO THE ILLUMINATION OF APU FIRE WARNING LIGHT. NORMAL LANDING. INSPECTED APU COMPARTMENT AND FOUND NO EVIDENCE OF FIRE OR OVERHEAT CONDITION. INSPECTED APU FIRE WARNING DETECTION SYSTEM AND FOUND PINCHED WIRES IN WIRE BUNDLE THAT GO TO PLUG D4816P. REPLACED APU FIRE BOTTLE AND SQUIB. REPLACED DAMAGED WIRE BUNDLE AND APU FIRE DETECTION SYSTEM CHECKED NORMAL.