Audi AG has admitted that 2.1 million of its diesel vehicles contain software code, known as a "defeat device," that thwarts emissions tests.
The fact that Audi, which is owned by Volkswagen, had sold its A3 models with the software is not new. The U.S. Environmental Protection Agency (EPA) sent a letter of complaint Sept. 18 to Volkswagen calling out half a dozen cars, including some model years of the Audi A3, as containing the defeat device.
Audi, however, admitted to the Reuters news agency that the A1, A3, A4, A5, A6, TT, Q3 and Q5 models all include the emissions-cheating software.
Reuters also said that there are "unconfirmed reports" that senior R&D heads working across the Volkswagen Group have been suspended. Reuters said the suspensions involved staff from the Audi, Porsche and VW brands.
Additionally, Czech-based Škoda Auto, also owned by Volkswagen, said 1.2 million of its cars carry the software.
Volkswagen chief executive Martin Winterkorn, who resigned last week as a result of the emissions-cheating scandal, is under investigation by German prosecutors, according to a report by the BBC.
Last week, the Volkswagen Group admitted that more than 11 million of its diesel cars worldwide had the "defeat device" installed, which leads to some vehicles emitting up to 40 times the amount of nitrogen oxides (NOx) allowed under government standards.
Volkswagen has apologized for its breach of trust with customers, who were told diesel cars were environmentally friendly.
Of the 2.1 million Audis with the emissions defeat code, 577,000 are registered in Germany, 847,000 in other western European countries and 13,000 cars are in North America.
The defeat device works with a simple line of code in the vehicle's electronic control module (ECM) that detects when an emissions test is taking place and sets the engine in "clean" mode for the remainder of the test. Once back out on the road, the vehicle reverts to its normal operating mode, where it emits far greater amounts of NOx.
"The Supervisory Board has authorized the Chairman to mandate German and US lawyers to objectively investigate and fully clarify the manipulation of emissions data of diesel engines," Volkswagen stated in a letter dated Sept. 25.