As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5089 - AFTER TAKEOFF FROM BWI RECEIVED A LEFT MLG DISAGREE WARNING MESSAGE, CREW DECLARED AN EMERGENCY AND DIVERTED TO PIT. FLIGHT LANDED WITHOUT INCIDENT. INSPECTED THE LEFT MLG SWITCHES AND TARGETS; NO DEFECTS NOTED. CYCLED THE LANDING GEAR MULTIPLE TIMES WITH PUMP 3A AND 3B INDEPENDENTLY. DISCREPANCY COULD NOT BE DUPLICATED.