I am having a problem with my nuvi 255
I am unable to uncheck CN MAP when I want to access other maps on sd card.
I was able to but not now ?.
I have done a reset ,screen calabration updated the software ect ...I know how to manage the maps through mp info screen.
My only thinking is that a file has been deleted bfore I ve backed it up
The maps I have on the sd card are able to be unchecked,but the CN MAP OVERIDES THEM