As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLE TO DCA. ON APPROACH TO DCA, CREW RECEIVED A LANDING GEAR AIR/GROUND FAIL MESSAGE. THE CREW DECIDED TO DIVERT TO IAD DUE TO ITS LONGER RUNWAYS. THE AIRCRAFT LANDED WITHOUT INCIDENT AND TAXIED TO THE GATE UNEVENTFULLY. MAINTENANCE DOWNLOADED THE CMC AND INSPECTED THE NOSE LANDING GEAR PROX SWITCHES AND HARNESSES AND FOUND A NOSE LANDING GEAR PROX SWITCH WITH A BROKEN PIN LODGED IN THE HARNESS. THE PROX SWITCH AND HARNESS WERE BOTH REPLACED AND THE LANDING GEAR SYSTEM FUNCTIONED NORMALLY.