Hi DevonJohn

My e39 started to do this a couple of weeks ago......and i spent a long time trying to diagnose the fault. For me, it worked out to be the Traffic Master module....it would not even turn on.....and was causing the Nav screen to flicker every 9 seconds....

I found the harness in the boot which connects to the harness to the monitor at the front and just unplugged it....and that got rid of the flickering screen.

So if you also have Traffic Master module (you will have a TM button where the cup holders are supposed to be in the front) just disconnect the module from the harness in the boot!

Hope this helps you.................