What is CAN Bus (Controller Area Network)?

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⁠How do CAN bus systems work?

⁠What is a CAN frame?

⁠History and evolution of CAN

⁠Future and development of CAN Bus

⁠Typical applications for CAN data

⁠Webfleet and CAN bus

⁠What is the difference between CAN and other vehicle network protocols like LIN, MOST or FlexRay?

⁠Is CAN bus only used in cars, or in other industries as well?

⁠What are the latest standards and the future of CAN technology (e.g. CAN FD)?

⁠How can I protect against unauthorized access and hacking attacks on CAN bus systems?

⁠What tools or equipment do I need to read and interpret CAN bus data from my fleet vehicles?

CAN bus (Controller Area Network) is a vehicle bus standard system that enables communication between multiple electronic control units (ECUs) without requiring a central computer. ECUs are electronic components in vehicles that monitor, control, and share data from different vehicle systems such as engines, brakes, airbags, and transmissions.

CAN bus is standard in: All modern vehicles including cars, trucks, buses, ships, electric vehicle (EV) batteries, construction machinery, agricultural equipment, and industrial automation systems.

How do CAN bus systems work?

CAN bus systems act as the nervous system in the human body. ECUs are like the parts of the body and interconnected in a vehicle. Various ECUs may have information that needs to be shared with other parts of the network. It enables each ECU such as engines, antilock braking/ABS, airbags, cruise control, electronic fuel injection, automatic gearbox, and battery systems, to communicate with each other without a central computer.

Essentially, it prepares and broadcasts information, like sensor data, over the CAN bus network. The data is then accepted by all ECUs – then the ECUs decide whether to receive the data or ignore it.

What is a CAN frame?

The communication between the ECUs over the CAN network happens via CAN frames. There are four types of CAN frames:

Data frame – the only frame for actual data transmission
Error frame – contains nodes to detect errors
Overload frame – injects when there is a delay between data and remote frame
Remote frame – a frame that requests information from a specific identifier

History and evolution of CAN

The Controller Area Network protocol was originally developed by Bosch in 1983 and officially released in 1986 at the Society of Automotive Engineers (SAE) congress in Detroit. The technology was first implemented in production vehicles by Mercedes-Benz in 1991. Since then, CAN bus has become the backbone of vehicle communication, with the standard being continuously refined through ISO 11898 specifications. The introduction of CAN FD (Flexible Data-rate) in 2012 marked a significant evolution, offering faster data transmission rates and larger payload capacities whilst maintaining backwards compatibility with classic CAN.

Future and development of CAN Bus

Looking ahead, CAN technology is poised to play an even more critical role as vehicles become increasingly connected and autonomous. The protocol is evolving to integrate seamlessly with Ethernet-based architectures, enabling more sophisticated vehicle-to-everything (V2X) communication. As electric vehicles and autonomous driving systems demand higher bandwidth and more complex data exchange, enhanced versions of CAN are being developed to coexist with newer protocols whilst maintaining the reliability and cost-effectiveness that made it the industry standard. Beyond automotive applications, CAN bus is expanding into industrial automation, medical equipment, and even aerospace, demonstrating its versatility and enduring relevance in an increasingly interconnected world.

Typical applications for CAN data

CAN bus data frames can be used in several use cases. For example, for fleet managers, logging vehicle data is essential to make informed decisions that reduce fuel costs and improve driver performance. For construction companies that operate with heavy-duty fleet telematics, data from tractors or trucks can be analysed to improve safety and lower costs. For professional service companies that make many deliveries in a day, can help predict and avoid breakdowns by logging CAN data to the cloud. These are just a few cases of logging CAN data.

Webfleet and CAN bus

At Webfleet - fleet management company, we understand the power of using data to optimise fleet operation and cost. That’s why we offer solutions equipped with CAN bus connectivity to help you take your fleet management to the next level, using telematics and telemetry.

Interested in how to stay connected to your business with valuable insight that help you boost productivity and improve efficiency? Get in touch with one of our experts today or check out our Webfleet fleet management software.

Low costs and straightforward

Because ECUs can communicate on a single CAN system, instead of complex dedicated wiring, it reduces weight, errors and costs.

Centralised

It enables central diagnostics, configuration and data logging on one point of entry through the CAN network.

Robust

Not easily impacted by electric disturbances or electromagnetic interference. The CAN bus standard is ideal for safety-critical applications (e.g. drivers in transport).

Efficiency

Data is prioritised without causing interruption to other frames.

What is the difference between CAN and other vehicle network protocols like LIN, MOST or FlexRay?

CAN bus is designed for robust, real-time communication between critical vehicle systems and is the most widely adopted protocol in automotive applications. LIN (Local Interconnect Network) is a simpler, lower-cost protocol used for non-critical systems like window controls and seat adjustments. MOST (Media Oriented Systems Transport) is optimised for high-bandwidth multimedia applications such as infotainment systems. FlexRay offers higher data rates and deterministic timing, making it suitable for advanced safety and drive-by-wire systems. For fleet management purposes, CAN bus remains the primary protocol as it provides the essential vehicle data needed for telematics, diagnostics, and performance monitoring.

Is CAN bus only used in cars, or in other industries as well?

Whilst CAN bus originated in the automotive industry, it has expanded far beyond passenger vehicles. Today, CAN bus is standard across commercial trucks, buses, construction equipment, agricultural machinery, marine vessels, and industrial automation systems. It's also used in medical devices, building automation, and even aerospace applications. For fleet management companies operating diverse vehicle types—from light commercial vehicles to heavy-duty trucks and specialised machinery—CAN bus provides a universal standard for accessing critical operational data across the entire fleet.

What are the latest standards and the future of CAN technology (e.g. CAN FD)?

CAN FD (Flexible Data-rate), introduced in 2012 and standardised under ISO 11898-1:2015, represents the latest evolution of CAN technology. It offers data rates up to 5 Mbps (compared to classic CAN's 1 Mbps) and supports larger payload sizes of up to 64 bytes per frame. This enhanced capability is particularly valuable for modern fleet management applications that require faster data logging and more detailed vehicle diagnostics. Future developments focus on integrating CAN with Ethernet-based architectures to support vehicle-to-everything (V2X) communication and autonomous vehicle systems. Webfleet solutions are designed to leverage both classic CAN and CAN FD data, ensuring your fleet management system remains future-proof as vehicle technology evolves.

How can I protect against unauthorized access and hacking attacks on CAN bus systems?

Securing CAN bus systems requires a multi-layered approach. Physical security is the first line of defence—restrict access to vehicle OBD-II ports and ensure only authorised personnel can connect diagnostic equipment. Implement secure telematics devices with encrypted communication channels and authentication protocols. Regular firmware updates for both vehicles and telematics hardware help patch known vulnerabilities. For fleet management, consider solutions that offer secure cloud connectivity and access controls. Webfleet's telematics solutions incorporate industry-standard security measures including encrypted data transmission and secure authentication, helping protect your fleet's CAN bus data from unauthorised access whilst maintaining seamless connectivity for legitimate fleet management operations.

What tools or equipment do I need to read and interpret CAN bus data from my fleet vehicles?

To access and interpret CAN bus data, you'll need a CAN bus interface device (such as an OBD-II adapter or dedicated telematics unit), appropriate software or a cloud-based platform to decode and visualise the data, and knowledge of the specific CAN database (DBC files) for your vehicle makes and models. For professional fleet management, integrated telematics solutions eliminate the complexity of manual CAN data interpretation. Webfleet provides plug-and-play telematics devices with built-in CAN bus connectivity that automatically capture, decode, and present vehicle data in an intuitive dashboard format. This eliminates the need for specialised technical knowledge, allowing fleet managers to focus on actionable insights like fuel consumption, driver behaviour, and predictive maintenance rather than raw CAN data interpretation.

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