What is an OBD system? What is the function and principle of an OBD system?

OBD stands for OnBoard Diagnostics, which means on-board automatic diagnostic system. The OBD system works by recording fault information and related codes when an emissions fault occurs. This information is then communicated to the driver via the malfunction indicator lamp (MIL) or the check engine warning light. Repair personnel use specialized equipment from the vehicle manufacturer to read the fault codes, quickly locating the fault and facilitating vehicle repair, significantly reducing the time required for manual diagnosis. Let’s learn more about the OBD system.