What was found
LAX - LANDING GEAR - FLT 0409 - ON DESCENT INTO LAX EN ROUTE FROM BOS WHEN LANDING GEAR WAS SELECTED DOWN, RECEIVED ECAM MESSAGE FOR LANDING GEAR NOT DOWN AND LOCKED. ALSO HAD 3 RED LIGHTS & LANDING GEAR DOOR OPEN INDICATIONS. RECYCLED LANDING GEAR HANDLE WITH SAME RESULT, THEN APPROXIMATELY 30 SECONDS LATER HAD NORMAL GEAR INDICATION. MAINTENANCE DOWNLOADED POST FLIGHT REPORT AND FOUND LGCIU NR 2 PROXIMITY SENSOR (39GA) TARGET POSITION MESSAGE. PER TSM 32-31-00-810-818, REMOVED AND REPLACED (SYSTEM 2) LT NOSE LANDING GEAR DOOR OPEN PROXIMITY SENSOR (39GA) IAW AMM 32-13-00-810-818, OPERATIONAL CHECKS WERE GOOD.