No GPS error Showing approximate location

As an additional thought, you can check the quality of the GPS signal with an app such as GPS Diagnostic by David Ryall. It's free in the app store. It will show you the satellites the phone is receiving (you need at least 4) and the quality of the Wi-Fi, Cellular and Bluetooth signals used to enhance GPS (I forgot to mention Bluetooth in my previous post).

GPS requires you to be outdoors with a clear view of the sky. Are you?

The iPhone supports "assisted" GPS (aGPS), but that requires that you have Wi-Fi turned on. Do you?

aGPS can also use cell tower triangulation. Do you have Airplane Mode off?

No heavy tree cover or tall buildings?

It's beginning to sound like your phone has a hardware problem.