GPS doesn’t work or takes long to find position:

If it takes long to get a GPS-fix even though you have mobile data, make sure that data is enabled (Settings -> More -> Mobile networks -> Mobile data traffic) and that the APN-type in your internet settings contains ”supl”. To check APN-type, go to Settings -> More -> Mobile networks -> Access point names -> [your internet settings]. The APN-type should be ”default,supl” or similar.

If you have problems getting the GPS to work first try the GPS with free sight to the sky. Surrounding objects like tall buildings and trees can block the signal from the satellites.
To test if the GPS works you can use an app like https://play.google.com/store/apps/details?id=com.chartcross.gpstest.

If the GPS is unable to get a fix with free sight to the sky, first try purging the assistance data and then restart the phone. To purge the assistance data, open the dialer and dial *#*#7378423#*#*, select Service tests -> GPS -> Purge assistance data and then restart the phone.

If this doesn’t help you should try updating the phones software.
You can do this using PC Companion: http://www.sonymobile.com/global-en/tools/pc-companion/

If the app GPS test works but apps like Google Maps is unable to determine your location you need to enable access to your location under Settings -> Accounts -> Google -> Locations settings -> Let Google apps access your location -> ON.