One problem related to door latch has been reported for the 2000 Lexus LS400. The most recently reported issues are listed below.
The doors automatacaly locked. I repeatedly hit the unlock button to try to unlock the doors. I then attempted to unlock the door manually with the button on the door. It still would not unlock. I went the the passenger side door and attempted to unlock the door. Still the door would not unlock. Then the alarm went off. The salesman got the key to get me out.