On my 2006 RX330, on occasion when I insert the ignition key I get a buzz for a fraction of a second. Car starts OK and no tell tale signs of a problem. I have changed the battery in the key and still the same. Any body have a clue. Never happened before.

 

Insertion of the key is normally followed by the steering wheel moving back to it's last position. Perhaps your steering wheel depending on how you have set it is a fraction out from where the car would normally retract the steering wheel to. Hence when you put your key in, it moves back to that spot just outside the "retraction" area.

 

Do you put the key in the ignition as you are closing the door with your other hand? If the door is open and you put the key in it will chime until you either remove the key or close the door, so maybe you are just sometimes just closing the door as you insert the key?

just a thought.

-Joe