What is the difference between OBDII and CAN?

OBD-II (On-Board Diagnostics II) and CAN (Controller Area Network) are related concepts but serve different purposes within the context of automotive diagnostics and communication.

OBD-II (On-Board Diagnostics II):

      • OBD-II refers to a standardized system for onboard diagnostics in vehicles, primarily used in North America (United States and Canada).
      • It encompasses a set of regulations and standards that mandate certain diagnostic capabilities and emission control monitoring in vehicles.
      • OBD-II includes a range of communication protocols such as J1850 PWM, J1850 VPW, ISO 9141-2, ISO 14230-4 (KWP2000), and ISO 15765-4 (CAN) to enable communication between a vehicle's electronic control modules (ECMs) and external diagnostic tools.
      • It provides a standardized way to retrieve diagnostic trouble codes (DTCs) that indicate specific issues with the vehicle's systems, including the engine, emissions, and other components.

CAN (Controller Area Network):

      • CAN refers to a communication protocol that allows various electronic control modules within a vehicle to communicate with each other efficiently.
      • It was initially developed for industrial applications but was later adopted for use in vehicles due to its reliability and efficiency.
      • CAN is not specific to diagnostics; it's a broader communication protocol used for real-time communication between different components in the vehicle, such as the engine control module, transmission control module, anti-lock brake system (ABS), airbag system, and more.
      • CAN protocols, such as ISO 15765-4 (CAN), are used within OBD-II systems to facilitate communication between the vehicle's systems and external diagnostic tools.

In summary, OBD-II and CAN are related but serve different purposes:

      • OBD-II is a standardized system for onboard diagnostics and emissions monitoring in vehicles, ensuring that vehicles meet regulatory requirements and allowing for the retrieval of diagnostic trouble codes.
      • CAN is a communication protocol used to facilitate communication between different electronic control modules within a vehicle, enabling them to exchange data efficiently. It's used not only for diagnostics but also for various other control and communication tasks within the vehicle's systems.