I recently bought a 2008 Mazda 5 , it had a dead battery.

Now with a new battery, the navigation screen says " A Program cannot be read. Please Consult a dealer"

I consulted the dealer and they said I would need to replace the navigation unit and it was expensive. I have been searching and it seems many people have the same problem, and some people suggested pulling the fuses that control the audio system , which I did, I pulled the power mirrors fuse and the Room fuse and it still displays the error. I then disconnected the battery and turned on the lights and held the brake down for 1 min then reconnected the battery and it still displays the error.

I have the North American Map DVD inserted, and my radio works, my radio seek and scan buttons work, but no other buttons work as I assume they require the screen to function to choose the source etc.
I was told there could be a SD card behind the glove box that might need replacing, but I'm having trouble finding that.

Does anyone have any suggestions for me, as I would like to be able to select other audio sources and change audio settings, both of which seem to require the navigation screen to be functioning.

Thanks.