As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DTW FLIGHT 3318 THE CREW REPORTED A NR 2 FIRE DETECT FAIL MESSAGE ON TAKEOFF. THE TAKEOFF WAS ABORTED AND AIRCRAFT RETURNED TO THE GATE. MAINTENANCE INSPECTED AND REPLACED THE NR 2 ENGINE FIRE LOOP DETECTOR AND CLEANED THE NR 2 ENGINE FIRE BOTTLE CANNON PLUG.