Self - Diagnosis Mode

Press the "BACK" switch and the "UP" switch of the 8-direction switches within 10 seconds after turning the ignition switch from OFF to ACC and hold them for 3 seconds or more. Then the buzzer sounds, all indicators of the preset switch illuminate, and the self - diagnosis mode starts.

Fig 1: Pressing BACK Switch And UP Switch
Courtesy of NISSAN NORTH AMERICA, INC.
The continuity of each switch at the ON position can be checked by pressing the switch. The buzzer sounds if the switch is normal.
NOTE:
The disk eject switch cannot be checked.