As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PASSING FL 310, CARGO FIRE FLASHING, DISCHARGE SWITCH TURNED ON AFT SIDE. EMERGENCY RETURN TO DEPARTURE. APU OIL SUSPECTED OF CONTAMINATING NR 2 BLEED AIR DUCT. PERFORMED PACK & DISTRIBUTION ODOR CLEARING PROCEDURE IAW MM 21-53-00-7. RAN NR 2 ENG & USED NR 2 BLEED AIR TO SUPPLY NR 2 PACK. BLEED AIR DUCT REACHED 100 C WITH NO SMOKE OR ODOR DETECTED. REPLACED 1 & 3 COALECER BAGS IAW MM 21-54-03-2.