How do I know if the Columbus head unit has a TV Tuner or not?

Is some additional device somewhere or is the difference the radio itself?

You know you have it as you can watch TV

 

It's a separate device, I think it lives behind one of the boot panels. It should also show up as a module during a diagnostic scan, address 57 if I remember correctly.

Thanks,

 

how can someone switch to TV on the radio, what buttons have to be pressed?

Media button, then TV or something different?

 

56 is the radio on mine, is it then 57, one number above?

From the user manual:

 

Yup, 57 is one above 56.

 

Example autoscan with a Columbus (37 and 56) and TV tuner (57) installed: https://forums.ross-tech.com/index.php?threads/12823/

you press the media button, twice in my case, the 1st press gives the bluetooth music, second gives tv.

the tv tuner lives in the drivers side boot compartment, not only can you see it when you open the door you hear its fan whirr everytime you open the boot.

 

If you don't have an L&k you don't have tv.