As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - INFLIGHT T844/12 AFTER TAKEOFF SHORTLY AFTER SELECTING GEAR LEFT MAIN LANDING GEAR ANNUNCIATIED ON THE MFD. RECYCLED GEAR AND PROBLEM RETURN. RETURNED TO ORD AND LANDED WITHOUT INCIDENT. ADJUSTED AND REPLACED KEYLOCK ON LEFT INBOARD GEAR DOOR LEG BUMPER. SYSTEM GROUND CHECKED NORMAL OPERATION.