Steering Switch

WARNING: This page is about a different car, the 2011 Nissan Leaf. However, it is still accessible from the selected car via links, so may be relevant.

Hands-free phone, possible driving distance display, voice control, and audio operations can be performed.
This switch is connected to the AV control unit, and the switch operation signal is transmitted to the AV control unit via voltage multiplex communication.

Fig 1: Identifying Steering Switch
Courtesy of NISSAN MOTOR CO., U.S.A.