Naive.. (As in Evian Water spelt backwards lol..
Its not simply a matter of comms protocol, it will be std rs232, I can give you the data in and data out lines no probs...
what are you gonna do with the results ??.. it aint gonna talk or give a menu to assist you. Its a matter of sending code combinations to the ecu and awaiting response. Unless you know the code combos, you are screwed, even if you located some code combos, then the format of the results are proprietry so, lets say, you send hex &H02 and get a 4 byte response of &HFF, &HB5,&H00,&H2C.. ??
How much wiser are you lol...
Joe.