As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OVERHEAT DETECTION LOOP A SHOWS A FAULT. GROUNDED - YES. PERFORMED B737-800 FIM 26-10 TASK 805. MW0325 HARNESS BAD. REMOVED AND REPLACED ENGINE 1 CORE FIRE DETECTION HARNESS MW0325 REF B737-800 AMM REF 26-11-02/401. ENGINE FIRE DETECTION OPS TEST OK. ETOPS GROUND VERIFICATION SUCCESSFUL.