As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO MIA DUE TO THE FLIGHT CREW REPORTING THAT DURING FLIGHT AT FL310 AN ENGINE 2 FADEC SYSTEM FAULT. THE AIRCRAFT LANDED SAFELY AT MIA AND TAXIED TO THE GATE UNDER ITS OWN POWER. MAINTENANCE REPLACED THE #2 ENGINE ELECTRONIC ENGINE CONTROL AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK PER AMM 73-21-55.