Serial data protocol on production autos.

[Shaw, Chris]

Hello,

 I am trying to get information on the ODB-II communication protocol used=
 in new production autos.  I would like to write code to monitor/modify v=
ehicle functions.  There are tools available which do this, however, I am=
 an engineer and thought it would be interesting to do it on my own. =20
 There are some ISO standards on "low-speed serial data communication" us=
ed in vehicles, but they are very expensive, and I am not sure if it's th=
e information I need.
 Any information would be helpful.  If this request doesn't fit into your=
 group, I apologize.

Thank you in advance,

Chris Shaw.