Volkswagen has revealed to U.S. regulators that there is additional suspect software in its 2016 diesel models that would potentially help their discharge systems run cleaner during government tests.
Volkswagen affirmed to The Associated Press that the "auxiliary emissions control device" at issue operates differently from the "defeat" device software included in the company's 2009 to 2015 models disclosed last month. That disclosure activated the worldwide cheating scandal engulfing the world's largest automaker.
The newly exposed software makes a pollution control catalyst heat up faster, improving functioning of the device that separates smog-causing nitrogen oxide into harmless nitrogen and oxygen gases.
VW spokeswoman Jeannine Ginivan said the new issue with the 2016 diesel models, known as secondary emissions control device, was first revealed last week to U.S. Environmental Protection Agency and California regulators.
"This has the function of a warmup strategy which is subject to approval by the agencies," Ginivan said. "The agencies are currently appraising this and Volkswagen is submitting additional information."
Automakers routinely place auxiliary emissions control devices on cars, though they are required by law to disclose them as part of the process to receive clean emissions certifications required to sell cars in the country.