On my 2015 Silverado 2500HD LTZ/Z71, I was surprised to find out that there was no HomeLink transmitter in the overhead console. Does anyone know if there is enough room behind my console to install a factory HomeLink transmitter out of a 2011 1500 Silverado?

 

Welcome to the fourm...
If its an option available on other levels of your vehicle then there should be room...The module itself, at least in my 2007 is no bigger than 3x4x1/2.. you will probably need to replace the overhead console portion that it fits in unless you are very skilled at cutting it out for the button...
Here is a picture of the back of my over head console with the GDO module circled , again this is in a 2007 Tahoe but its probably similar...
I had mine out because I was looking for a power source for a dash-cam..

Your best bet is to open it up and take a look, mine has a bit more room also because I have a sun roof...