The CAN bus Wikipedia page states that:
CAN bus is one of five protocols used in the on-board diagnostics (OBD)-II vehicle diagnostics standard. The OBD-II standard has been mandatory for all cars and light trucks sold in the United States since 1996, and the EOBD standard has been mandatory for all petrol vehicles sold in the European Union since 2001 and all diesel vehicles since 2004.
The OBD Wikipedia page further states that:
2001: The European Union makes EOBD mandatory for all gasoline (petrol) vehicles sold in the European Union, starting in MY2001 (see European emission standards Directive 98/69/EC).
2003: The European Union makes EOBD mandatory for all diesel vehicles sold in the European Union
2008: All cars sold in the United States are required to use the ISO 15765-4 signaling standard (a variant of the Controller Area Network (CAN) bus).
Except the 2008 date these quotes primarily talk about the OBD/EOBD. How is the OBD and CAN exactly related? Is CAN a mandatory protocol for OBD-II/EOBD? In case it was I see a conflict in the 1996 and 2008 dates for United States...
My final question is simple - are there certain dates since which all cars sold in particular markets have to use CAN bus for the internal communication between car's electronics?
The reason I am asking this is I want to reverse engineer the signaling from various vehicle sensors (steering angle sensor etc.). If I knew something like "all European cars since 2004 use CAN for the internal communications between electronic parts" that would help me a lot.
Obviously the CAN bus is somehow mandatory since 2008 in the US at least. However, I do not know to a what degree in detail - usually there are CAN bus pin-outs on the OBD-II connector. However, there may be multiple CAN buses present within a single vehicle - one for critical functions like ABS, ESP etc. and another for infotainment like radio etc. I wonder if any of these buses has to be connected to the OBD pin-out...