The Environmental Protection Agency (EPA) on Friday came out with the shock announcement that the Volkswagen Group had installed software on close to 500,000 of its TDI-branded diesel models from the Volkswagen and Audi brands that was designed to circumvent EPA emissions standards for certain air pollutants.

ALSO SEE: VW Diesel Emissions Recall: What You Need To Know In 10 Questions

Labeled a Defeat Device by the EPA, the software was said to be able to detect when an official emissions test was being run and in such a case turn on full emissions control systems. During normal driving conditions, the cars were said to pollute more, with some emissions such as nitrogen oxide (NOx) said to be as much as 40 times higher than current standards allow.

The software was said to be fitted to certain cars powered by a turbocharged 2.0-liter four-cylinder diesel engine, a recall for which is currently underway. The specific models mentioned were the 2009-2015 Beetle, 2009-2015 Golf, 2009-2015 Jetta and 2014-2015 Passat from VW, and the 2009-2015 A3 from Audi. Sales of the cars plus newer examples have also been halted.

DON'T MISS: Optional Clock Will Set Bentley Bentayga Buyers Back Nearly $170K

The VW Group has since issued a statement that includes an apology from CEO Martin Winterkorn.

“I personally am deeply sorry that we have broken the trust of our customers and the public,” Winterkorn said in the statement. “We will cooperate fully with the responsible agencies, with transparency and urgency, to clearly, openly, and completely establish all of the facts of this case.”

VW is working closely with the EPA as well as the California Air Resources Board (CARB) in dealing with the issue. The automaker has also ordered an external investigation of the matter.

VW is now facing the possibility of major fines and perhaps even criminal charges.

For more on the matter, read the in-depth report over at The Car Connection.


Follow Motor Authority on Facebook and Twitter.