As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB, THE CREW REPORTED A LANDING GEAR AIR/GROUND FAIL MESSAGE. THE QRH WAS FOLLOWED, AND MAINTENANCE CONTROL CONTACTED TO DISCUSS THE ISSUE. IT WAS THEN DECIDED TO DIVERT TO KCMH. THE CREW DECLARED AN EMERGENCY. THE LANDING GEAR WAS LOWERED NORMALLY AND THE AIRCRAFT LANDED WITHOUT INCIDENT. DURING INSPECTION ALL FOUR LOWER MAIN GEAR PROXIMITY SWITCHES WERE FOUND TO BE BAD. THE PROXIMITY SWITCHES ON THE LEFT AND RIGHT SHOCK ABSORBERS AND TRAILING ARMS. GEAR SWINGS WERE THEN PERFORMED WITH NO FURTHER DEFECTS NOTED.