This is bothering me for some times now. When I press lock on the UX remote key, if any of the doors are open, I get nothing. No beep, nothing. The other day, my kids left the rear passenger door slightly open. I came back after 30mins, all the lights are still on. I thought I locked the vehicle with all the light off, and it was not.

On my previous Lexus, when I do the same thing, there's a long beep coming from the vehicle, so I know one of the door is open. Anyone know how to set this?

 

This is a setting but It is not normally accessible by the user. Checkout this This Lexus Personalized Settings document.

#28 Door Lock Buzzer
When the lock button on the electronic key is pressed and a door is not fully closed:

• The buzzer will not sound = Off
• The buzzer will sound (Default) = On

You can visit the dealer and ask/pay them to make the change. Alternatively, I purchased a OBD Link MX+ and used the Carista app to change hidden options like these myself.

 

I actually took my vehicle to the dealership. The "Expert" Technician told me the car suppose to work like that. He shows me another brand new UX that was doing the same thing. Nothing they can do.

After spend $10 for Carista app like you suggested, I was able to correct the problem myself. It turn out I need to set "Allow locking when a door is still open" to OFF.