As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PILOT HAD A LT FIRE LIGHT COME ON SHORTLY AFTER TAKEOFF. LT ENGINE WAS SHUTDOWN AND FIRE BOTTLE WAS ACTIVATED. AIRCRAFT THEN RETURNED TO AIRPORT. MAINTENANCE INSPECTED FIRE DETECTION SYSTEM AND FOUND THE FIREWALL FIRE DETECTOR FAULTY. FIRE DETECTOR WAS REPLACED AND AIRCRAFT RETURNED TO SERVICE.