> custom codes are accessible only through proprietary equipment

That's not strictly true; if the tool designer knew the codes, then they could access them, too.

Strictly speaking, OBD-II allows extensions to the protocol, and those extensions need not be published. Thus, only people with information on the extensions can create tools to read and interpret them. Often, this means the manufacturers and their licensees.

The excuse given by manufacturers for NOT turning over this information is for the consumers' protection because some of the codes/commands can cause damage to vehicular systems. The software in the cars is not designed to prevent stupidity or misuse, and so they only want educated personnel to have access to those features.

I've had conversations with the fellow from obd-2.com and he said that if we can get him a way to purchase a volvo scanner, he'd do it and start adding stuff to the software. Anybody know how this could happen?

-cj