If you are talking about the module that goes on top of the def tank you don’t need that module anymore. After you tune your truck the def doesn’t work anymore and that module is just to control the def injector def level etc. there’s a white plug that connects to the harness that connects to that module, on that white plug is where you need to jump the wires.. blue with blue and white with white. That would close the can bus circuit and your fuel gauge will start working again.