Volkswagen has disclosed to U.S. regulators that there's additional suspect software in its 2016 diesel models that would potentially help exhaust systems run cleaner during government tests.
Volkswagen confirmed to The Associated Press that the "auxiliary emissions control device" at issue operates differently than the "defeat" device software included in the company's 2009 to 2015 models disclosed last month. That disclosure triggered the worldwide cheating scandal engulfing the world's largest automaker.
The issue with the 2016 vehicles was first disclosed last week to Environmental Protection Agency and California regulators. The new software makes a pollution-control catalyst heat up faster, improving the device's performance in separating smog-causing nitrogen oxide into harmless gases.
Regulators are working to determine whether the new software constitutes a second effort to game emissions tests.