As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE 'ENG 4 FIRE LP B' EICAS STATUS MSG DISPLAYED. ENG 4 FIRE LOOP-B FIRE OR FAULT OUTPUT. CREW COMMENTS: DISPLAYED FOR 3 HOURS THEN WENT AWAY. FOUND WIRE CHAFING ON LWR FIRE LOOP WIRE AND SENSOR LOOPS CHAFING ON SUPPORT STATIONS. REPAIRED WIRES, OP CHECKS GOOD.