As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW RECEIVED A CARGO FWD FIRE SYS FAIL MSG AFTER TAKEOFF, DECLARED EMERGENCY AND RETURNED TO BUF. AIRCRAFT LANDED WITHOUT INCIDENT. ON CALL MAINTENANCE WAS DISPATCHED TO THE AIRCRAFT. PLACED THE FORWARD CARGO PIT FIRE DETECTION SYSTEM ON MEL, AND THE A/C WAS RETURNED TO SERVICE.