“Software is in everything,” he said, citing airplanes, medical devices and cars, much of it proprietary and thus invisible. “We shouldn’t use it for purposes that could conceivably cause harm, like running personal computers, let alone should we use it for things like anti-lock brakes or throttle control in automobiles.”

Source: www.nytimes.com

Apparently there is no “hardware” in the diesels to confuse the EPA, but an open collaboration around “software” might help this be contained and consistent across automakers. The EPA should write this software I think and make is open source (if for the public good).