As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PIT - FL 8076 - ON DESCENT INTO PIT, CREW LOWERED GEAR AND RECEIVED THREE GREEN LIGHTS WHILE BLUE LIGHTS IN GEAR HANDLE REMAINED ON AND A MFDU MESSAGE THAT READ 'LEFT LG DOWNLOCK SWITCH'. AT 400 FEET THE THE AURAL WARNING FOR THE GEAR CAME ON. CREW RECYCLED GEAR AND LIGHT EXTINGUISHED. FLIGHT LANDED IN PIT WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED THE LEFT MLG PRIMARY DOWNLOCK SENSOR. (M)