See also:

Troubleshooting guide
Verify the location of all Intelligent Keys that are programmed for the vehicle. If another Intelligent Key is in range or inside the vehicle, the vehicle system may respond differently than expect ...

Preventing the Intelligent Key from being left in the vehicle
If you lock all doors using the power door lock switch with the Intelligent Key in the vehicle, all of the doors unlock immediately and the buzzer will warn you when the door is closed. ...

Warning signals
To help prevent the vehicle from moving unexpectedly by erroneous operation of the Intelligent Key or to help prevent the vehicle from being stolen, a chime or buzzer sounds from inside and outsid ...