AT&T shuts down its 3G network Tuesday. Will it impact your car’s navigation system?

Do you rely on your car’s navigation, traffic or roadside assistance features? Then you may wake up to an unpleasant surprise Tuesday when AT&T shuts down its 3G network.

While our smartphones stopped relying on 3G long ago, that’s not the case for our vehicles’ telematics systems, which capture a car’s location, speed, idling time, harsh acceleration or braking, fuel consumption, vehicle faults and other data. That loss of GPS data means your car’s built-in navigation system may stop working Tuesday.