I know the thread title is going to make me seem a bit of a wally but my previous understanding was that the maps are stored in the car, updated occasionally by Fords awful system. You input where you want go and the car system calculates your route. The satellites constantly calculate where you are and feeds that info to the car which constantly updates the map display and tells you when to turn etc. However last week on a 700 mile return trip to Northumberland, the satnav diverted me around a couple of accidents (which I knew about from google maps on my phone). So my question is, how did the system know about these accidents? How is that info transmitted to the car? Surely not via the satellites which just give position? I know when the car was new I got the years free traffic service subscription from Ford but that has long expired? So how did my car get to know about these accidents?  

25 minutes ago, Vendee said:

 So how did my car get to know about these accidents?  

Maybe it's a Smart Car?? 🤣

My car does the same. I suspect that in some cases Ford's subscription service is pretty duff and it is unable to disable it so it doesn't.

I have the same on my 2019 Kuga, I've done nowt to update it since I bought it a year ago but it points out motorway holdups etc.

8 minutes ago, anon said:

My car does the same. I suspect that in some cases Ford's subscription service is pretty duff and it is unable to disable it so it doesn't.

Yeah well mine did expire after a year but then I had the TCU (modem) exchanged when they all seemed to fail some time ago. The exchange unit I received obviously had the previous owners traffic subscription still on it so I got the traffic info back for a while but then it went again. I don't get any warnings on screen about roadworks up ahead like I did when I had the subscription but obviously it is diverting me away from delays. I do get the road colour on screen change to amber or red when the traffic slows down ahead.

Sync 3 while not as advanced at the newer systems, uses the signals sent over the traffic channel via FM frequencies and will add roadworks and traffic issues in real time if a incident is on your planned route it will adjust if needed or requested 

I have a 2017 with no FordPass or smart connectivity etc

 

 

Ah! Thank you. That makes a lot of sense and would explain it.

4 hours ago, Jim3797 said:

Sync 3 while not as advanced at the newer systems, uses the signals sent over the traffic channel via FM frequencies and will add roadworks and traffic issues in real time if a incident is on your planned route it will adjust if needed or requested 

I have a 2017 with no FordPass or smart connectivity etc

 

 

 

 

Thanks for the explanation Jim. I guess its a bit like "Live Traffic" Lite.

The satellites just send synchronised time signals (allowing for relativity!) and the car device calculates where it is on the Earth's surface.

The traffic data comes via whatever other system is used.
Our Tom Tom requires a Bluetooth connection to the Internet via a mobile phone hotspot.
Other systems are used and this seems to be explained here:

https://www.techwalla.com/articles/how-does-live-traffic-on-gps-work

 

On 7/27/2025 at 9:12 AM, Shearers said:

The satellites just send synchronized time signals (allowing for relativity!) and the car device calculates where it is on the Earth's surface.

Yes, it's a one way communication, GPS satellites don't get anything back from the cars. Aside, mobile apps on your phone, that don't have the (huge) local maps on board (like Sync does) require an internet connection to get the map.