Liang's name first appeared in a lawsuit against VW filed by New York and Massachusetts, which claimed VW executives knew about the cheat devices. According to the lawsuit, Liang allegedly developed a device for the 2.0-liter TDI engine found in the Volkswagen Jetta. The engineer reportedly started developing the emissions-cheating device in 2006 and was testing the device at one of the automaker's facilities in California.
In a report by the US Department of Justice, Liang admitted to creating the defeat device when he and his co-conspirators discovered that VW's diesel engines would not be able to meet stricter US emissions standards. The device, Liang admits, was able to recognize when the vehicle "was undergoing standard US emissions testing on a dynamometer or being driving on the road under normal driving conditions, in order to cheat the emissions tests." Liang stated that he and his co-workers knew VW's diesels were falsely being marketed as "clean diesels."
Liang also admitted to helping others lie to federal and state regulators, as well as to customers after regulators voiced concerns about VW's diesel-powered cars. The Detroit News reports that Liang was also indicted for violating the Clean Air Act, which includes a term of two years in prison and a fine of $250,000. But under the plea agreement with the US DOJ, Liang did not enter a plea to that charge.
There's no word on whether other VW employees will be charged in the emissions scandal with Liang scheduled to be sentenced on January 11. Liang had worked at VW's headquarters in Germany starting in 1983, with the engineer relocating to the US in 2008 where he held the title of Leader of Diesel Competence.