As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI, CREW OBSERVED 'FADEC MAINTENANCE ALERT' ON NR 1 ENGINE. FLIGHT CREW ELECTED TO RETURN TO GATE. AIRCRAFT RETURNED TO GATE WITHOUT INCIDENT. MAINTENANCE PERSONNEL IDENTIFIED AIR/OIL COOLER SHUT-OFF VALVE FAILED. REPLACED SHUT-OFF VALVE. ENGINE GROUND RUN, NO FAULT NOTED. AIRCRAFT RETURNED TO SERVICE. (X)