As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#2 ENG FIRE HANDLE DID NOT ILLUMINATE ON TEST. GROUNDED - YES. CONFIRMED CORE LEFT DETECTOR FAILED RESISTANCE TEST PER B737-9 IFIM 26-11-00-810-823, REMOVED & REPLACED ENG #2 CORE LEFT LOOP A FIRE DETECTOR AND PERFORMED INSTALLATION TEST GOOD REF B737-9 AMM 26-11-01/401.