Volkswagen has been ordered by the federal government to recall 500,000 vehicles after it was found that it installed software that enabled its vehicles to unlawfully pass emission regulations. 

The charge stemmed from the so-called "defeat device," which turns emission control off when being subjected to testing but not when the car is in actual use, The Verge reported. What this means is that vehicles running the software pass emission tests, but fail to meet emission standards when driven normally. If the emission control is off - as was the case in the cars to be recalled - the nitrogen oxide emission spikes to as much as 40 times the standard, the Environmental Protection Agency said.

Through the "defeat device" mechanism, Volkswagen is - in effect - violating the Clean Air Act, the same regulation that Hyundai and Kia violated. They were penalized with a record-setting $100 million fine, according to The New York Times. The affected vehicles are dominated by diesel passenger cars bought starting from 2009. These include 2009-15 Volkswagen Jetta, 2009-15 Beetle, 2009-15 Golf, 2014-15 Passat and 2009-15 Audi A3.

Aside from the recall, the federal government is also poised to slap the German automaker with fines of as much as $18 billion, according to the Associated Press. There is also possibility of criminal prosecution. "They appear to have designed a system with the intention to mislead consumers and the government. If that's proven true, it's remarkable and outrageous," Tylon Slocum, director at Public Citizen, told the New York Times.

Volkswagen has already been ordered to recall 420,000 cars in August due to airbag problems, as reported by HNGN earlier. It is not yet clear what the recall entails on the side of affected vehicle owners.