Gps in iphone 4 not working

Question

I have an iPhone 4 whose GPS is misbehaving.  I use the latest version of Navigon, and it always loses the GPS signal and puts me in the wrong place on the map.  I have also checked the GPS location in the standard Maps app, same result.  This began a couple of months ago with no warning.  The phone had been on iOS 5.1.1 since the update released, hasn't been damaged by liquid or impact.  It just, well, fizzled.  Quite frustrating.  I have already tried a restore from backup and a restore as new.  Any ideas?  HELP!!!

Answer 1

The iPod Touch does NOT have GPS circuitry and consequently the GPS satellites can not be accessed.  Here is a mini-education.  The last paragraph gives you a solution.
GPS signals are separate from and completely unrelated to both the Internet and the cellular telephone network.  GPS signals come directly from the GPS satellites.  They provide latitude and longitude information to GPS receivers.  Navigation software then takes that latitude/longitude info and converts it to land mass, roads, bridges, highways, buildings, etc.
Most navigation software stores the maps right in the iPad/iPod/iPhone but a disadvantage is that the maps must be periodically updated (perhaps once every two years).  The Internet is not required to use the system but it is required to update the maps.
Some navigation software gets the maps from the Internet and requires an Internet connection to function but an advantage is that the maps are always up-to-date.
The WiFi+3G/4G iPad and the iPhone both have a GPS receiver.  The WiFi-only iPad and the iPod do not and these devices require an accessory.