As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 949 - EWR-PIT - DURING TAXI, AIRCRAFT RETURNED TO GATE DUE TO LT ENGINE FIRE WARNING ILLUMINATED. MAINTENANCE INSPECTED AND REMOVED AND REPLACED FIRE DETECTION BOX AND FIRE LOOP, OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)