Hi,

I do not know if the functionality is enabled only for the US/EU firmware, but I can tell you an easy way to check and setup the EcoRoute HD.
I have an EU version of the 3790T, which I upgraded to the 3490 firmware.
Anyhow, the EcoRoute HD was working OK even with the original firmware.

To set up the HD, please go to the Apps tab and open the ecoRoute application

[Only registered and activated users can see links. ]

[Only registered and activated users can see links. ]

In the ecoRoute application go to the upper left corner (the 3 lines) and open the HD Connection screen. Press the 'title' HD Connection

[Only registered and activated users can see links. ]

[Only registered and activated users can see links. ]

It will guide you thru the steps to set up the link.

If everything goes fine you will get some extra screens in the GPS, one of them being the Gauges:

[Only registered and activated users can see links. ]

I believe that as long as you can go thru these screens you should be able to setup the EcoRoute HD.
The process is very similar with the original 3790T screens.
Anyhow, if you read carefully the steps to install the 3490 firmware you can get some more functionality from the GPS