As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT ENGINE FIRE WARNING DURING FLIGHT OCCURED DURING CRUISE, NO ABNORMAL ENGINE INDICATIONS, WARNING WENT AWAY AFTER 5 SECONDS F SYSTEM FAULT REOCURRED LATER R ENGINE FIRE DET REDUND LOSS. C/W VISUAL INSPECTION OF LEFT ENG LOOP DETECTORS AND PYLON DETECTOR. NO TROUBLE FOUND. MAY NEED FIDEX MPN 475084-10. NO CURRENT MSG . FIRE TEST ACCOMPLISHED TEST PASSED. AS PER A220 AMP 26-11-10. (LP# 7755788)