what are the black buttons on the door handles ? what do they do ?

 

they lock the doors.

 

Like Jim posted the black buttons located on the front (top surface) of the door handle lock the doors. I admit this was confusing to me initially. With smart key the doors unlock when you place your hand into/under the handle where there is a sensors to detect it and unlock that door.

A couple of years ago whil eon a road trip, a friend I was traveling with inadvertently was depressing the black door lock handle button on front passenger door while I repeatedly pressed the smart key fob to unlock the doors. I hit the unlock button 4-5 times with nothing happening before I realized something was amiss. Once I realized what he was doing I asked my friend to release the lock button which he did but at that point. Unfortunately the LS430 then refused to unlock any doors or trunk using any method locking us out for approximately 10-15 minutes. After 10-15 minutes I pressed the unlock on the key-fob again and the system worked and unlocked the doors to my great relief (as we were about 300 miles from home).