OBD Modes are different services provided by the ECM, such as clearing codes or monitoring live data. Manufacturers are not required to support all modes and they are allowed to create additional modes (manufacturer specific data). Each mode has is own unique identifier signified by $xx, where xx represent the hex identifier. Each OBD-II mode is briefly described below:
We will take a more in depth look at each mode individually in later articles, where we will see the use of each mode’s identifier.