[DieselTaz]

In the Feature and parameters list there is a parameter label Multiplexing. From there you can change the source address for a bunch of parameters. Each Manufacture tends to have different source addresses for their body controllers. Pretty much the ECM needs to know where the signal request is coming from for the particular parameter. Example: Engine brakes forom Cab Controller.....I think. I flashed a ISX in a pete and when the params were loading into ECM I accidentally snagged the USB from computer. It was rather awful because I was relatively new to Insite and didnt have a template nor printed out the parameters before the cal download. Spent all day playing with source addresses. 

Hope this helps. I am by no means an expert on any of this stuff. I just learn from my screw ups....(I learn alot)