Nav System Has Failed

[Bethany7687]

I have a 2007 ES350 with nav. At about 50k miles the navigation system failed. The cursor starts to spin around. The next time I start the car, screen displays "Check System". When I press 'map' the message is "the external system is not connected." It takes several days for it to work again. This definitely happens more in cold weather. Now I can't get it to work more than a few minutes. When it first happened a year ago, the dealer told me it was out of warranty and wanted $2200 to replace it. Has anyone experienced this? Any suggestions?

[Step Hen]

I would pull the main radio unit out and check the wiring's condition and see if any connections have become loose