There are two categories of Diagnostic Trouble Code(DTC)’s that apply to OBD-II.
Type A
- Emissions related.
- Requests illumination of the MIL after one failed driving cycle.
- Stores a freeze frame DTC after one failed driving cycle.
Type B
- Emissions related.
- Sets a Pending Trouble Code after one failed driving cycle.
- Clears a Pending Trouble Code after one successful driving cycle.
- Turns on the MIL after two consecutive failed driving cycles.
- Stores a freeze frame after two consecutive failed driving cycles.