Navigation System Symptom Troubleshooting

Symptom Diagnostic procedure Also check for 
No picture is shown on the display Troubleshooting  
The picture is missing a Red, Green or Blue color or tone Troubleshooting  
Display unit buttons do not work Troubleshooting  
Satellite mark in the GPS mark is not indicated Troubleshooting Electronic aftermarket accessories 
Audio driving instructions cannot be heard Troubleshooting Vehicle position wanders on the map 
Vehicle position wanders on the map Troubleshooting Satellite mark in the GPS mark is not indieated