The C510 is not an integrated GPS-receiver. There isn't a GPS receiver inside the Sony Ericsson C510 but the Google Maps application enables you to find your approximate position on a map quickly and easily, using information from mobile cell sites to determine the area you're in. There is the option to employ exact GPS satellite location-finding with the C510, however, by connecting the C510 wirelessly to a standalone small Buetooth GPS module (you will have to buy one of these separately, though).
how do i connect my c510 phone to a gps reciever
GPRS settings for SE C510