On-Board Diagnostic (OBD) is an automotive diagnostic system used in vehicles built after 1996.
The OBD system is in a small black box and is used to monitor malfunctions, speeding and misuse of the vehicle. The OBD system records ignition on/off, driving time, distance traveled, speed and maximum speed. These driving parameters are registered with the time and date.
Later, the functionality of the on- board diagnostics was extended to the extent that the diagnostic tools detect defective or heavily stressed components and list them for the repair shop so that they can be replaced.