My tom tom has lost gps help! all of a sudden half way through a journey my tom tom lost all GPS signal and wont pick up anything? is there anything i can do to get it back?

Here are some tips on what to do ,To pinpoint your location, you need to get signals from at least 4 satellites. If you receive signals from less than 4 satellites or the signals are not strong enough, the Driving View stays grey and one of the following messages is shown in the bottom right corner of the Driving View:

• Waiting for a valid GPS signal
• The GPS signal was lost sec ago

Note: In previous versions of the TomTom application the message may vary.
If you see any of these messages, try the following:

Finding a GPS signal
In the following cases it can take up to 5 minutes to find your current position:

• You use your TomTom device for the first time.
• You haven't used your TomTom device for a longer time.
• Your TomTom device has been relocated without using it (e.g. after travelling by plane or train).

If it takes longer than 5 minutes, make sure that you are in an open place without tall buildings or trees around you.
Once your TomTom device has located your current position, the Driving View is shown in full colour and shows your position on the map.
Tip: Most TomTom devices can use QuickGPSfix™ to locate your current position faster. Flight mode
On devices with built-in GPRS connectivity, flight mode also disables your device’s GPS reception.
To switch flight mode off, tap Flight mode in the preferences menu and then select Restore connections.
Clear View
Your TomTom device must be outdoors to locate your current position.
Try repositioning your device in your car; ideally, try to position it at the lowest possible point directly on the windscreen.
Some vehicles have a heat reflective shield embedded in the windscreen, which may prevent your device from locating your current position. If this is the case in your vehicle, use the TomTom External Antenna Kit (available as an accessory).
Tip: As a reference, place your device outside your parked car to see if it can find your current position.
Reset your device
Reset your TomTom device. Click here to learn how to reset your device.
Install the latest application
We recommend always having the latest version of our application installed on your device.

Go outside and hold the power button down for 45 secs. Should fix the problem. Got this from Tom Tom support.