What does OBD stand for in cars?

[Juan]

OBD in cars stands for On-Board Diagnostics, a system that continuously monitors the engine's operating conditions to check if the vehicle's emissions exceed standards, and immediately issues a warning if they do. When a system malfunction occurs, the malfunction indicator lamp or check engine warning light will illuminate, while the powertrain control module stores the fault information in memory. The fault codes can be read from the PCM through a specific procedure. Based on the fault codes, maintenance personnel can quickly determine the nature and location of the fault. The OBD interface is generally a 16-pin female connector, trapezoidal in shape. Some vehicle models have a protective cover over the OBD port, and common OBD interfaces are black, white, or blue.