Audio System Symptom Troubleshooting - Audio unit button does not work

Audio unit button does not work
  1. Switch list
    With navigation:
    FM, AM, TA, VOL, , CD, AUX, 1-6, FOLDER, TUNE, SKIP, SCAN/A.SEL, MAP/GUIDE, CANCEL, MENU, AUDIO, , INFO, ENTER
    With premium:
    1-6, LOAD, EJECT, FM, AM, TA, CD/AUX, TITLE, CLOCK, SCAN, RTY/FOLDER, SKIP, A.SEL, RETURN, ENTER, MENU
    Without premium:
    1-6, EJECT, FM, AM, CD, TA, CD, AUX, TITLE, CLOCK, SCAN, PIY/FOLDER, A.SEL, SKIP, VOL, RETURN, ENTER, MENU

Are all the items in the appropriate switch list detected?
YES -
Operation is normal.■
NO -