As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#2 ENGINE FIRE DETECTOR B LOOP DOES NOT TEST. GROUNDED - YES. FIRE DETECTION CONTROL MODULE FAULTS #2 ENGINE LEFT CORE LOOP. #2 ENGINE LEFT CORE LOOP REMOVED AND REPLACED REF B737-800 AMM 26-11-00. OPERATIONAL CHECK GOOD AND NO FAULTS ON CONTROL MODULE. GROUND VERIFICATION SUCCESSFUL. THIS CLEARS MEL 26-2B.