As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE IN E & E BAY FOUND FAULT LOGGED ON ENGINE/APU FIRE DETECTION UNIT FOR NR 2 ENGINE UPPER FAN LOOP B DETECTOR. CLEANED TERMINAL CONNECTIONS TO THE NR 2 ENGINE UPPER FAN FIRE DETECTOR ASSY AND PERFORMED ENGINE FIRE DETECTION OPERATIONAL TEST REF MM 26 11 00 OPS NORMAL. NO FAULTS NOTED.