Originally Posted by pdqford

Now a days all these vehicles have their computers (modules) connected to a CAN, that's a Controller Area Network so that they can share data between them. Each computer has to know what the id is of each other computer so it knows what data it is getting off the BUS.

So as Shawn said, the correct way to swap out a module is to first dump its software onto the NGS, then remove the old module, install the new module, and then reload its original software. That way none of the computers think anything has been changed.

Batteries going dead should have no effect on the each computers id or software as it is stored in the computers non-volitle memory.