As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 738 FROM TOL TO SLW - DURING CRUISE OPERATION THE LOWER CARGO FIRE WARNING CAME ON. AIRCRAFT DIVERTED TO EVV, EMERGENCY WAS DECLARED AND THE AIRCRAFT LANDED WITHOUT INCIDENT. POST FLIGHT INSPECTION WAS PERFORMED, LOWER CARGO COMPARTMENT WAS EMPTY NO DEFECTS WERE NOTED. REMOVED AND REPLACED CENTRAL CONTROL UNIT OPS CHECKED GOOD. AIRCRAFT WAS RETURNED TO SERVICE.