2015-2020 Tahoe radio swap issue

[gellisc89]

So I’m swapping my head unit on my 2015 Tahoe ls from the stock smaller 4.3 in to the stock 8 inch I got it all in and cannot get my touch screen to work , I have all my steer wheel controls and the audio works just fine but can’t se to figure what I need to do to get the video working on the unit

 

[Jake707]

Im not an expert but if its all hooked up correctly I think that a new ECM flash of some sort might be needed so the vehicle recognizes the new components you added.

 

[gellisc89]

Im not an expert but if its all hooked up correctly I think that a new ECM flash of some sort might be needed so the vehicle recognizes the new components you added.

How is this process done