As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON LANDING ON FINAL LEG TO RETURN TO HOME BASE PILOT INDICATED A FIRE WARNING LIGHT AND DING IN THE HEADSET. INDICATED THAT THERE WAS NO FIRE AND CONFIRMED AFTER LANDING. TROUBLESHOOT THE FIRE DETECTION SYS IAW MM AND FOUND ON A FUNCTION TEST THE TURBINE HEAT DETECTOR ACTIVATED AT 350 DEG INSTEAD OF THE RATED 520 DEG. NO OTHER DEFECT WERE FOUND IN SYS. REPLACED DETECTOR WITH NEW, PERFORMED FUNCTIONAL TEST AND GROUND RUNS, NO DEFECTS NOTED. RETURNED TO SERVICE.