OBD-II

In part 1 of How OBD-II Vehicle Diagnostics Work we quickly went over some history of electronics in cars and why you should care about OBD-II, even if you’re not an automotive buff.

Then, we went over some OBD-II basics and touched on the 4 “sub-standards” of the OBD-II main standard.

You learned about passive and active states and we went over OBD-II data packet structure before dissecting a typical OBD-II data packet.

The post finished with a quick overview of diagnostic trouble code (DTC) structure and my promise to take a closer look at each of the four OBD-II standards in part 2 of the series.

[Read more…] about How OBD-II Vehicle Diagnostics Work, Part 2: A Closer Look

Since January 1^st, 1996 all vehicles have been required to have On-board Diagnostics II, also known as OBD-II.

On-board diagnostics existed before then, but the process for reading diagnostic data varied from manufacturer to manufacturer.

If you knew the “secret” sequence, you could use your car key to turn the ignition switch a certain way and hopefully get the check engine light to blink out the error code. Not only did you need to know the correct sequence for the ignition switch, you had to then be able to decode the blinks.

[Read more…] about How OBD-II Vehicle Diagnostics Work