Volkswagen's Withdrawal of EPA Application Is Not Because of 'Defeat Device' (Update)

Update: Official statement from EPA.

During his voluntary testimony for a congressional committee Thursday, Volkswagen of America CEO Michael Horn announced the company would withdraw their application for emissions certification for 2016 model year Volkswagens powered by 2-liter diesel engines.

However, the reason for that withdrawal is not directly related to the “defeat device” that’s been at the center of the ongoing diesel controversy.

In his his prepared statement, Horn said:

In Volkswagen’s recent ongoing discussions with the regulators, we described to the EPA and CARB that our emissions control strategy also included a software feature that should be disclosed to and approved by them as an auxiliary emissions control device (“AECD”) in connection with the certification process. As a result, we have withdrawn the application for certification of our model year 2016 vehicles. We are working with the agencies to continue the certification process.

(Emphasis mine.)

Also is the key word in this paragraph, as in “in addition to” the defeat device. Therefore, the auxiliary emissions control device is another component — whether legal or illegal — that must be declared to the Environmental Protection Agency on the application for certification. Since the AECD was not disclosed, Volkswagen must withdraw their application.

So, why did a number of outlets attribute the withdrawal of the application to the defeat device? Well, it’s a little complex.

By its definition, according to the EPA at least, a defeat device is an auxiliary emissions control device that “reduces the effectiveness of the emission control system under conditions which may reasonably be expected to be encountered in normal vehicle operation and use.” However, not every AECD is a defeat device.

Auxiliary Emission Control Device means any element of design which senses temperature, vehicle speed, engine RPM, transmission gear, manifold vacuum, or any other parameter for the purpose of activating, modulating, delaying, or deactivating the operation of any part of the emission control system.

What exactly is the auxiliary emissions control device in this case? Only Volkswagen knows for sure at this point. It could be software used to manage fuel delivery to the exhaust system to heat up the catalytic convertor for the purpose of reducing emissions.

Currently, the EPA knows as much as we do.

“Volkswagen did very recently provide EPA with very preliminary information on an auxiliary emissions control device (AECD) that Volkswagen said was included in one or more model years. The U.S. EPA and the California Air Resources Board (CARB) are investigating the nature and purpose of this recently identified device,” an EPA spokesperson told TTAC.

If the AECD is a legal piece of software, Volkswagen must simply declare it and resubmit the application. This scenario is the most likely possibility. It would also allow Volkswagen to, at some point in the near future, sell model year 2016 diesels in the United States.

However, if the software device is illegal, Volkswagen may have some re-engineering and re-explaining to do.