As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB THE L ENG FIRE LIGHT ILLUMINATED. RETURNED TO 4A9 ON A PRECAUTION DUE TO NOT BEING ABLE TO VERIFY IF THE ENG WAS ON FIRE. AFTER INSPECTION AND GROUND TEST IT WAS DETERMINED THE SYSTEM WAS WORKING CORRECTLY AND THAT THE L ENG FIRE LIGHT WAS PROBABLY CAUSED FROM THE SUNLIGHT ENTERING THE COWLING.