As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 6115, CVG TO CMH, CREW RECEIVED A LANDING GEAR AIR/GROUND FAIL MESSAGE AFTER TAKEOFF. THE CREW DID NOT ATTEMPT TO RETRACT THE LANDING GEAR AND RETURNED TO CVG AND LANDED WITHOUT INCIDENT. MAINTENANCE DOWNLOADED THE CMC AND FOUND CMC MESSAGES FOR THE LEFT WOW PROXIMITY SWITCH FAIL. DURING INSPECTION OF THE GEAR THE LEFT WOW PROXIMITY SWITCH WAS FOUND TO BE BAD. THE PROXIMITY SWITCH WAS REPLACED AND THE AIR/GROUND SYSTEM OPERATED NORMALLY.