To enable the headset-function, you have to short-circuit the "3" and "4". After a short time there is "Headset" on the display Now, menu 3-6 is now enabled!
To enable the carkit-function you have to short-circuit the "4" and "5". After a short time, "Car" is shown on the display and the menu 3-7 is enabled!!
This Trick is for you how want to hear more then your supposed to !
If you short-circuit the left and the right contact with the middle contact ("3", "6" and "9") the Nokia Software hangs! The profile "Headset" will be activated. Before you do this, just active the "auto call receive" function in the headphone profile and set the ringing volume to "mute" Now you can use your phone for checking out what people are talking about in a room. Place the phone somewhere stratidic and call your phone! The phone receives the call without ringing and you can listen to what people are talking about!