AV Switch Self-Diagnosis Function: Notes
WARNING: This page is about a different car, the 2005 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.
It can check ON/OFF operation of each switch in the audio unit (without NAVI) or AV switch (with NAVI) and diagnose the input signals from the steering switch (with NAVI) (except TRIP on the steering wheel audio control switch).