What was found
AIRCRAFT WAS GROUNDED: LEFT MAING GEAR DOOR SIS NOT CLOSE RETURNED TO PHOENIX AND LANDED OVERWEIGHT WITHOUT INCIDENT. AFTER LANDING GEAR EXTENSION, LEFT MAIN LANDING GEAR DOOR DID NOT CLOSE COMPLETELY, AND GENERATED L/G DOORS NOT CLOSED ECAM. MAINTENANCE EPLACED LEFT MLG DOOR UPLOCK PER AMM 32-31-33-400-002-A.