-can high/low are totally not needed for obd2 reading/writing. these are drivetrain communication wires
-also +12v wires are in the wrong place, need ecu pin 2 and 37, add a switch between wire to 37 to simulate ignition
see scheme. edc15vm+ connects the same way as edc15p+ btw.
http://mhhauto.com/attachment.php?aid=68953and test it with vcds or something first...