i have bought Vitz 2012 model recently. it has DVD (made in china , company name HANGDAO) with GPS and navigation buttons on it but problem is that my GPS navigation is not working with error "No GPS". There is also a port under GPS button. . i went mozang for resolution of said issue, they said that car DVD is without GPS and i must install some device in it to activate GPS navigation from midgumri road lahore or i should buy new DVD with GPS.
i am confused what to do?? please let me know how much that extra device for DVD cost? i dont want to buy new one.

thanks in advance.