[Nuvi 250W] GPS problem : not at the right place

Hello,

My nuvi 250W have a problem. It works good but the position of the car is not at the good place. The gap with the right place is aproximatly 50 meters.

Is it possible to reset gps settings?
Or is it possible to update the system (not the map)? What software is needed?

Thank you for your next responses.

There is a setting called "display on street" or similar, that will solve your problem.

I d'ont have this setting...