As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW DECLARED AN EMERGENCY ON APPROACH AFTER THE LOSS OF FMS GUIDED FLIGHT PLAN. MAINTENANCE FOUND BOTH VIA NR 1 & 2 DATA BUSS FAULT CODES 344343 AND 344344. REPLACED BOTH VIA NR 1 AND 2 IN ACCORDANCE WITH THE AMM. ALL TESTS NORMAL AND THE AIRCRAFT HAS RETURNED TO SERVICE.