OBD2 trouble codes are part of a troubleshooting system that helps you track down the source of your engine’s problems. For example, if the engine’s computer recognizes a malfunction during operation, it isolates it, translates it into a code and saves it so you can access it. You retrieve it using one of the methods outlined here. Let’s say the code indicates a too-rich oxygen-to-fuel ratio. Look this up in a repair manual and you’ll see this is usually liked to a faulty oxygen sensor. Replacing it solves the problem and the code resets.
Retrieve OBD2 Codes Using Your Ignition Key
Turn the ignition key “On” and “Off” without cranking the engine. How many times you do this depends on your particular vehicle. Most Chryslers require five times; other cars require three. End with the key in the “On” position. Start the sequence anew if you accidentally crank the car.