Diagnosis Function

WARNING: This page is about a different car, the 2003 Infiniti M45. However, it is still accessible from the selected car via links, so may be relevant.

It can illuminate all the indicators (LED) in the multifunction switch.
It can check for continuity of the switches by sounding the buzzer when the multifunction switch is pressed.
It can check for continuity of harness between multifunction switch and rear control switch (audio), or steering switch (audio).

NOTE: When it check continuity of harness between multifunction switch and rear control switch (audio), rear control cancel switch is OFF position.