As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 2007 - RIC - AFTER TAKING OFF OF DCA TO CLE, FLIGHT CREW REPORTED LANDING GEAR AIR GROUND FAIL MESSAGE ON EICAS. CREW DIVERTED FLIGHT TO RIC AND LANDED ACFT UNEVENTFULLY. RIC MX FOUND CORROSION ON NOSE DOWN PROX SWITCH. MX CLEANED CORROSION AND PERFORMED OPERATIONAL CHECK SUCCESSFULLY. ACFT WAS APPROVED TO RETURN TO SERVICE.