Volkswagen has confirmed that the disputed 'auxiliary emissions control device' operates differently from the 'defeat' software included in the company's 2009 to 2015 models.
According to The Guardian, the new software was first revealed to Environmental Protection Agency (EPA) and California regulators on September 29. This prompted the company last week to withdraw applications for approval to sell the 2016 model cars in the United States.
US regulators said that further questions arose after they saw the company's disclosure of additional suspect engineering of 2016 diesel models that would potentially help exhaust systems run cleaner during government tests.
A criminal investigation is ongoing against Volkswagen for violating the Clean Air Act for its earlier emissions cheat, as well as a raft of state investigations and class-action lawsuits filed on behalf of customers.
Volkswagen also faces fines of billions of dollars.