As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW MADE AN AIR RETURN TO DEPARTURE DUE TO AN ELECTRONIC CENTRALIZED ACFT MONITORING MESSAGE FOR NLG DOORS NOT CLOSED AND LANDING GEAR SYS DISAGREE. MX REMOVED AND REPLACED THE LANDING GEAR SELECTOR VALVE AT POSITION 41GA AND PERFORMED A FUNCTIONAL TEST OF LANDING GEAR DOORS WITH NORMAL RESULTS. THE ACFT WAS RETURNED TO SERVICE.