because battery disconnection will not work and might require your
vehicle computer reprogrammed by the dealer. Before doing so, please
contact your dealer or you can inquire at
http://www.automotivetroubleshootingsecrets.com if you are a member.
OBD2 codes can also use disconnecting the battery but may interfere
with your accessories. Example: you might need to record your cd or
audio code to reset it.
domestic and imported cars and trucks have its own system to retrieve
the code yourself. Most of these models are made before 1995 for
domestic vehicles and 1993 for imported vehicles. After that, you need
a scanner to retrieve the engine fault code.