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Do all vehicles with OBD2 have a CAN-bus? Otherwise, what are the alternative buses used?

Are there special versions of the buses for trucks and school-buses than for cars/suv/vans?

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up vote 4 down vote accepted

The answer would be yes if the vehicle was produced after 2008, otherwise no. in the following article it states it is required as one of the signalling protocols in OBD2 Post 2008.

So presently vehicles that are currently being produced do have a CAN channel included in the OBD2 Connector. However, there are are pins in the OBD2 that are manufacturer specific. And there are usually multiple CAN-buses in the modern Auto-mobile, as I have drawn from my experience.

You will also see the alternative buses in the link as well.

Again, please be aware that much of OBD-II is manufacturer specific.

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What was used prior to 2008? – Cynthia Avishegnath Jan 19 '14 at 23:50
It just means that it was not required, meaning an auto manufacture was not required to have can connection on the specific pins referred to in the link. The key thing to remember is that only some of the pin contacts are defined by OBD II where as the other ones are defined differently at each manufacturer. – am6sigma Jan 20 '14 at 15:55

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