2015 Volkswagen Touareg TDI
The Environmental Protection Agency has accused Volkswagen of violating the Clean Air Act a second time as it named six late-model vehicles, including those from Audi and Porsche, with so-called “defeat device” software designed to skirt federal emissions laws.
The 2014 Volkswagen Touareg TDI, 2015 Porsche Cayenne diesel, and 2016 Audi A6, A7, A8, A8L, and Q5 TDI models were cited today in a separate violation from the company’s 482,000 noncompliant 2009–2015 diesels announced by the EPA on September 18. There are roughly 10,000 Touareg and Cayenne models affected and an “unknown volume” of 2016 Audi models.
Volkswagen, in a statement from Wolfsburg headquarters, denied allegations it had purposely cheated emissions on these engines.
“Volkswagen AG wishes to emphasize that no software has been installed in the 3-liter V6 diesel power units to alter emissions characteristics in a forbidden manner,” the company said. “Volkswagen will cooperate fully with the EPA [to] clarify this matter in its entirety.”
Porsche Cars North America tiptoed more cautiously over the subject.
“We are surprised to learn this information,” the sports-car maker said in a separate statement. “Until this notice, all of our information was that the Porsche Cayenne Diesel is fully compliant.”
Volkswagen previously said it had withdrawn EPA certification for all 2016 diesels since it did not disclose an “auxiliary emissions-control device (AECD)” on the applications. During three lab tests, including some conducted by the California Air Resources Board and Environment Canada, the EPA said these cars—all with 3.0-liter V-6 diesel engines—emit up to nine times the allowable nitrogen-oxide (NOx) emissions when the software detects the vehicle is not being tested. In comparison, the 2.0-liter four-cylinder diesel models expel between 10 and 40 times the allowable NOx emissions.
Specifically, the FTP 75 (federal emissions test procedure) runs for 1370 seconds, and “exactly one second” later, the EPA said the software switched from a “temperature conditioning” mode to a “normal mode”—allowing for “different injection timing, exhaust gas recirculation rate, and common-rail fuel pressure.” When the vehicle runs without sensing any test procedure, the “temperature conditioning” mode is never activated even when cold, the agency said.
Such software is common and completely legal during cold startups, at which point automakers must “light off” the catalytic converter as quickly as possible to gain acceptable emissions levels. In VW’s instance, the “temperature conditioning” mode directed the exhaust to run hot in order to heat the selective catalytic-reduction system—which includes two catalytic converters and urea injection—so they could better reduce NOx. That would have been fine. However, Volkswagen violated the law by not disclosing this software to the EPA and by employing code that explicitly switched the car’s emissions system from a bench-testing mode that actually outperformed federal standards to allowing dirtier emissions under regular conditions.
The EPA has not issued formal penalties nor has the National Highway Traffic Safety Administration conducted any recalls related to these diesel models.
UPDATE 11/2, 4:40 p.m.: This story has been updated to include statements from Volkswagen AG and Porsche Cars North America.