What was found
FLT 80 - BWI - LAS - EL - CREW REPORTED DURING DESCENT RECEIVED AN ECAM WARNING MESSAGE THAT THE LEFT FRONT LANDING GEAR DOOR DID NOT CLOSE WHEN THE GEAR WAS LOWERED FOLLOWED BY A NOSE WHEEL STEERING FAULT. A GO AROUND WAS EXECUTED AND THE CREW REQUESTED LAS TOWER TO CONFIRM GEAR WAS DOWN. TOWER CONFIRMED GEAR WAS DOWN, CREW DECLARED AN EMERGENCY. THE CABIN WAS NOT PREPPED. THE LANDING WAS UNEVENTFUL. MX PINNED AND INSPECTED THE NOSE GEAR. THE A/C WAS TAXIED TO THE GATE. MX FOUND THE NOSE GEAR DOWN LOCK SENSOR 19GA FAULTED. MX REPLACED 19GA IAW 32-31-73. TEST PASSED. THE A/C WAS RETURNED TO SERVICE.