Navigation System Symptom Troubleshooting - Navigation cannot control audio/disc

Navigation cannot control audio/disc
Diagnostic Test: Navi System Link
  1. Go into the Diagnostic mode, and use the ‘‘Navi System Link'' diagnostic.
Is the ‘‘Radio'' icon red?
YES -
Do the troubleshooting for the voice guidance cannot be heard. ■
NO -
Go to Step 2 .
  1. Substitute a known-good navigation unit, and recheck.
Can the navi control audio/disc?
YES -
Replace the navigation unit. ■
NO -
Do the audio system troubleshooting.■