2001 BMW 740iL Navigation and Radio Problem - Anyone have an idea about the problem?

Question

My nav/computer screen is blank and my radio mutes itself every 2min and 40seconds.

Answer 1

First, check the fuses relevant to the audio/video/navigation systems.

If everything is OK,

try unplugging the NAV module (at the left side of the trunk compartment) overnight. Do this with the key off. If it still does not work in the morning when you re-attach it, chances are that you have a bad NAV module. Rarely, the video display goes out (you failed to mention if you have the small or the bigger display, or if you have a rear display).

But this is a costly repair and naturally a second opinion (dealer's opinion) is warranted. There are several items that interconnect with each other which could bring down the system.