As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD FLT 5849 - THE CREW REPORTED A LANDING GEAR LEVER DISAGREE MESSAGE ON APPROACH WHEN THE LANDING GEAR WAS LOWERED. RECYCLED GEAR AND MESSAGE CLEARED. MESSAGE RE-APPEARED AT THE GATE. MAINTENANCE INSPECTED AND REPLACED THE LEFT MLG DOWN LOCK PROXIMITY SWITCH AND PROXIMITY SWITCH INDICATING HARNESS. OPERATIONAL CHECKS WERE GOOD.