As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT NUMBER 2703, LANDING GEAR AIR/GROUND FAIL EICAS MESSAGE ON CLIMB-OUT. ACFT RETURNED TO FIELD. MAINTENANCE REMOVED AND REPLACED THE NLG PROXIMITY SENSE HARNESS ASSY. ACFT WAS TEST FLOWN WITH NO DISCREPANCIES NOTED AND SUBSEQUENTLY RELEASED TO SERVICE.