There are some in-vehicle communication protocols that are CAN based. These are mainly historic protocols, that were started and developed before the appearance of CAN protocol.
In this section you can read about SAE J1708 and SAE J1587 protocol standards.
The Society of Automotive Engineers (SAE) develops and maintains standards for the industrial applications like inter ECU communication in motor-vehicles. The J1587 is a higher layer protocol description based on the physical layer of J1708.