As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: VMO GEAR DOWN STATUS MESSAGE. PILOTS RETRUNED TO PHL, DECLARED AN EMEREGENCY AND LANDED OVERWEIGHT WITHOUT INCIDENT. MAINTENANCE PERFORMED FIM 31-50-F1-14A-421. OVERSPEED WARNING IN GEAR DOWN-SWITCHED TO NORM.