According to Road and Track, a DOJ spokesman confirmed that Bosch hasn't been accused of any actual wrongdoing just yet. In order to officially charge the supplier, the DOJ would need to be proof it knew that VW was using its technology to cheat. Bosch's official line is that it simply built the components to Volkswagen's specs.
"How these components are calibrated and integrated into complete vehicle systems is the responsibility of each car maker," Bosch said in the early stages of the diesel scandal, R&T reports. The report also cites a story from Germany's Bild am Sonntag, which claims Bosch warned VW about emissions cheating eight years ago. Specifically, Bosch called the cheating software a "defeat" code while warning that it should only be used for testing and not added to road cars.
This particular furor surrounds Bosch's EDC 16 and EDC 17 engine-control modules, which serve as the base for emissions controls on VW's (and several other European OEMs) diesel engines. According to Road and Track, each manufacturer comes up with its own software and specs for the Bosch ECMs, although an unnamed auto-industry software engineer said that doesn't mean the supplier wasn't aware of what was going on.
"Bosch is involved in all the development we ever do. They insist on being present at all our physical tests and they log all their own data, so someone somewhere at Bosch will have known what was going on," the anonymous engineer told R&T. "The car company is never entitled by Bosch to do something on their own."
We'd recommend keeping an eye on this one.