If the TomTom App is not able to locate your current position, there are several things you should check.
The TomTom App for iPhone gets your current position from the GPS receiver in your iPhone. It also uses the iPhone’s Location Services to find your position faster. Location Services require a data connection.
On your iPhone, go to Settings > Privacy > Location Services. Make sure Location Services is switched on.
Your iPhone must be outdoors to locate your current position. Try repositioning your iPhone 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, that may prevent your iPhone from locating your current position.
Tip: To check if your iPhone is working properly, place it outside your parked car to see if it can find your current position.
By default data roaming is disabled when you travel abroad. If you cannot get a GPS signal abroad in a reasonable time, you may want to allow data roaming temporarily.
To allow data roaming, do the following:
Note: Receiving data abroad may incur additional charges on your phone bill. You can reduce the amount of data by stopping the Mail application checking for mail when abroad.