As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO DFW DUE TO AN LGCIU 2 FAULT AFTER TAKEOFF. THE AIRCRAFT LANDED SAFELY AT DFW WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED LANDING GEAR DOOR CLOSED PROXIMITY SENSOR 29GA AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK.