As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF THE CREW REPORTED AN LGCIU FAULT AND RETURNED DEPARTURE. NO EMERGENCY WAS DECLARED AND LANDED SAFELY WITH NO FURTHER INCIDENT. AIRCRAFT WAS GROUNDED. MAINTENANCE REPLACED THE NR 1 LGCIU AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK IAW AMM 32-31-70-000-001A AND 31-71-400-001A.