What was found
IAH - FLIGHT 2318, THE CREW REPORTED A LANDING GEAR AIR/GRND FAIL MESSAGE ON EICAS AFTER TAKEOFF. THE AIRCRAFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE LEFT TRAILING ARM PROXIMITY SENSOR, OPERATIONALLY TESTED WITH NO DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.