I understand that one of the CAN protocol that OBD2 uses to read vehicle data is ISO 15765-4. However this is the one that is used by generic OBD2 reader devices like ScanTool; And it provides a limited set of vehicle parameters (PIDs). Also generic OBD2 readers just provide some fault codes!

I got to know that another CAN protocol ISO 15765-3, which is meant for enhanced diagnostics and provides a larger set of vehicle parameters primarily for diagnostics. Is this correct?

Is there software/tool available, I can get that uses this protocol; which in turn enables me to read larger set of vehicle parameters for enhanced vehicle diagnostics?

  • You might look at Ross Tech's VCDS product. It is VW specific but has some very good support and forums. Those might help you understand the challenges of building/finding a general purpose tool (at a reasonable price). SnapOn also makes scan tools, which I would assume are general purpose. If you're interested in a specific brand of vehicle you might ask specifically about it. Many of the advanced tools I've heard of sound vehicle specific.
    – dlu
    Nov 21, 2016 at 12:51
  • I have a couple of SNAPON units work very good but also very expensive. But you may want to look at the interfaces these folks have if your looking for a PC based interface. SIMMA CAN INTERFACES Nov 21, 2016 at 15:46

2 Answers 2


There is no magic bullet.

Generic OBDII is the only one that gives a predefined set of data. The manufacturer specific or "enhanced" data is entirely up to the manufacturer. This means there is no standard. There is no protocol that covers everyone.

Without telling us what exactly you want to do with the data or what vehicles you want to talk to these are your choices.

  1. Buy the manufacturers specific tool that covers the vehicle you want. These tend to be very expensive. Most but not all manufacturers have switched to a laptop based solution. These tend to be very expensive because the manufacturer effectively sets their own price.
  2. Buy a generic tool that has manufacturer specific capabilities. There are many manufacturers such as SnapOn or Genesis. These tend to be expensive because the maker bought the protocol specs from the manufacturer or reverse engineered them.
  3. Reverse engineer the protocol yourself.
  • Thanks @vini_i Could you give me some pointer/details on 'reverse engineering on manufacture specific protocols' ? Nov 23, 2016 at 10:25
  • @AkhileshGupta could you ask that as a separate question. That way it will be easier to answer without trying to do it in the comments
    – vini_i
    Nov 23, 2016 at 12:49

Perhaps OpenXC is what you are looking for.

  • 1
    Not really! I am fairly familier with OpenXC. But that also follows 15765-4 protocol as a generic OBD reader; NOT the specific diagnostic protocol 15765-3! I get again a limited parameters via OpenXC! Nov 22, 2016 at 4:40

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .