As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CREW PREFLIGHT, MN CARGO LOOP 2 STATUS MESSAGE DISPLAYED. MTC PERFORMED OPS CHECK OF THE MAIN CARGO COMPARTMENT SMOKE DETECTION SYSTEM IAW B767 AMM 26-14-00 NO DEFECTS NOTED AIRCRAFT RELEASED ETOPS 180. ACFT RETURNED TO SERVICE.