As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - FLIGHT 2278, THE CREW REPORTED A LANDING GEAR AIR GROUND FAIL MESSAGE ON CLIMB. THE AIRCRAFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE NOSE LANDING GEAR DOWN LOCK PROXIMITY SWITCH, OPERATIONALLY TESTED WITH NO DEFECTS. THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.