Volkswagen will have to recall 482,000 cars in the U.S. after it seemingly deliberately violated Clean Air Act emissions laws on its TDI diesel models, according to a report from the Environmental Protection Agency.



On 2009 through 2015 Jetta, Beetle, Golf, and Audi A3 TDIs and 2014–2015 Passat TDI models, Volkswagen installed software that allows 10 to 40 times the allowable level of nitrogen oxide, a predominant exhaust gas from diesel engines. The EPA, after receiving a tip from transportation researchers at West Virginia University, found “a sophisticated software algorithm” referred to as a “defeat device” that let the vehicles exceed lawful NOx emissions levels on the road while blocking them when the car detected it was undergoing EPA emissions testing. 

The software uses steering angle, speed, engine run times, and atmospheric-pressure information that “precisely track the parameters of the federal test procedure used for emission testing,” according to the EPA.


In a statement to Car and Driver, VW spokesman John Schilling said, “VW is cooperating with the investigation; we are unable to comment further at this time.” The company has not said why it specified increased NOx emissions on these vehicles. All of the affected engines involve four-cylinder turbo-diesels, but only some use the exhaust-gas after-treatment AdBlue, a urea-based liquid that many diesel passenger cars need to pass emissions laws in the U.S. but not in Europe and elsewhere. Starting with the 2015 model year, Volkswagen rolled out a revised version of the EA288 2.0-liter diesel, at which point all American-market VW and Audi TDI models adopted the AdBlue system. Prior to that, only the Passat and Touareg TDI used the fluid on 2012 and newer models, along with the A6, A7, and A8 TDI.

Under the Clean Air Act statutes, the company could be fined up to $37,500 for every vehicle found in violation. That could equal fines approaching $18 billion if the government were to seek maximum penalties. CARB executive officer Richard Corey said the violations were a “direct threat to public health.”


VW admitted it had installed the software only after the EPA and the California Air Resources Board hinted that they would not certify the company’s 2016 diesel models. In May 2014, West Virginia University researchers found “significantly higher” emissions from a 2012 Jetta TDI and a 2013 Passat TDI and reported this information to the EPA. In December 2014, Volkswagen updated ECU software on certain cars to address the issue, but CARB found minimal improvements and could not figure why the OBD-II controller wasn’t indicating any emissions errors. During this time, Volkswagen’s various answers did not explain the “higher test results consistently confirmed during CARB’s testing.”