What is on-board diagnostics (OBD)?
On-board diagnostics (OBD) is a vehicle diagnostic system that has been developed to detect and report errors and faults in different vehicle systems. Originally introduced to monitor exhaust emissions, OBD has been developed over the years into a comprehensive system that can monitor a range of vehicle components and systems and deliver detailed information about the vehicle’s state and performance, considerably simplifying troubleshooting and rectification. Thanks to the OBD interface, technicians and vehicle owners can use a diagnostics device to call up this information.
Roles in modern on-board networks
In modern vehicles, OBD is an integral component of the on-board network. It not only monitors emissions systems but also important vehicle functions such as the engine, gears, brakes and safety functions. OBD systems use the vehicle’s communication infrastructure to gather data from different control devices (ECUs). Standardized protocols such as CAN bus (Controller Area Network) then transmit this information further to the OBD interface where error codes can be read and diagnostics information called up, enabling fast and precise troubleshooting.
Communication technologies and protocols
The OBD system is based on different communication protocols that can vary according to the vehicle manufacturer and model. The most common standard is OBD II which has been in use in most vehicles since 1996. OBD II uses the CAN bus to gather diagnostics information from the control devices and make it available via the OBD interface. Other protocols which are particularly used in older OBD systems include ISO 9141, KWP2000 and J1850.
Future developments
With the progressive development of vehicles into autonomous and networked systems, OBD technologies are also further developing. Future OBD systems could be used to gain an even deeper insight into vehicle diagnostics by integrating more complex data streams from high-speed networks such as the Automotive Ethernet. Not only would this improve troubleshooting, it would also make the maintenance and repair of vehicles more efficient. In addition, the integration of over-the-air (OTA) updates could also enable vehicle software and diagnostics functions to be updated remotely without having to take the vehicle to a workshop.
Challenges and possibilities
One challenge in the further development of OBD systems is guaranteeing cyber security, as networked vehicles are more vulnerable to digital attacks. Therefore, progress in encryption technology and safe communication will be fundamental in protecting the integrity of OBD systems. At the same time, the extended diagnostics capabilities of OBD offer new potential for the development of preventive maintenance concepts which minimize vehicle failures and extend the service life of components.
Thus, on-board diagnostics will remain an essential component of vehicle technology, continuing to evolve in line with the increasing requirements for connectivity and complexity of modern vehicles.
Klaus Bramhofer
Klaus Bramhofer is the Head of Technical Product Management at MD. His mission is to establish MD as a supplier and development partner for connector components in the automotive industry. With an experience of more than 15 years in this industry, Klaus is an expert in this field. After starting his career as an Application Engineer, he established and managed a development department in his position as Manager Development Sensor Cables. Apart from the close contact with customers and working in a global team, Klaus particularly appreciates the intercultural experiences he gains in his job.