As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER LANDING CREW NOTED RT ENG FIRE DETECT SYS FAILURE. ACFT WAS FERRIED BACK TO HOME BASE. INVESTIGATION REVEALED ENG FIRE DETECTOR LOOP CHAFFED THROUGH UNDER THE AFT ENG HEAT SHIELD, GREEN SHEETS AT INBD END. CAUSE WAS DUE TO IMPROPER ROUTING AT LAST ENG CHANGE. DETECTOR WAS REPLACED WITH NEW PART & ACFT RETURNED TO SERVICE.