Probably you should start with looking into the CAN component for PSoC. Maybe buy a CAN extension board (http://www.cypress.com/documentation/development-kitsboards/cy8ckit-017-canlin-expansion-board-kit ). When you succeed in that, its mostly a matter of decoding the actual protocol. Maybe you can find a library that uses other hardware that you can adopt?
Thanks for the reply and I am aware of the kit and I know of a hardware option as mentioned. I am looking to see if anyone has developed a j1939 app that does the querying and decoding. I know I could do it but why re-invent the wheel. Or is some have tried with no real success than I want to know. I also need to look at time-vs-money on using the hardware option.