As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING OVHT/FIRE WARNING CHECK, ENGINE NO. 1 FIRE WARNING SWITCH DOES NOT ILLUMINATE IN 'B' CONFIGURATION. GROUNDED - YES. PERFORMED ENGINE FIRE DETECTION OPERATIONAL TEST PER B737-800 AMM 26-11-00-710-801. OPS CHECK GOOD AND BITE TEST ON THE ENGINE AND APU FIRE DETECTION CONTROL MODULE GOOD AT THIS TIME AND NO FAULTS PRESENT AT THIS TIME.