Note that CAN is just another way of talking about a physical layer plus some can frames (similar to how ethernet mac + physical layers), but on top of that there are many protocols, like ISO-BUS or other protocol layers etc. I'm afraid these are often proprietary on it's own, and then there is the manufacturer which implements their own CAN messages / flow diagrams to communicate, connect devices onto the bus, handle error situations, etc.
So my guess would be it's hard to get the data out, however it may be interesting to see what can frames would pass by from the device itself (I guess this device has to connect to another control unit on the bus).