Hello, I'm Cam. Please include all the details about your issue so I can accurately advise you. I cannot see your vehicle so please be detailed.
What car are you working on?
This is a general question, if the software version appears on the CAN BUS and can tell about the structure of the BUS ?
Different models of same manufacture has different bus structure (like Ford Focus and Ford Mondeo). Sometime even the same car model has different structure (depending on engine type). I wonder if there is a way (like using the sw version) that can uniquly identifies the bus structure
Well, in the GM system, the bus is a high speed bus with a twisted pair running at a voltage of 2.5V, and it is a loop with a terminating resistor in different modules or a stand alone resistor. This should be standard for the CAN OBD 2
It is not. There are some parameters that reside in different places
it is not what?
The OBD2 is standard but is being implemented differently by various car makers. Thus the BUS structure is not alike various models and various makers.