Software To Be Updated In All 2009-2016 VW, Audi V-6 Diesels

It was only three weeks ago that Volkswagen headquarters in Germany came out swinging against the U.S. Environmental Protection Agency.

The EPA had issued a complaint in which it accused VW of incorporating emission-cheating software into its 3.0-liter V-6 TDI diesels, used by Audi and Porsche as well.

But it appears the company's tone has changed since then.

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Last Friday, the company met with regulators from the EPA and the California Air Resources Board, and told them that the emissions problems with its 3.0-liter V-6 diesel engines extended to 75,000 more vehicles than it had first acknowledged, according to Reuters.

That means that every single Audi, Porsche, or Volkswagen sold in the U.S. with that engine since 2009 has the problematic software, boosting the total from 10,000 to 85,000 vehicles.

Then, yesterday, Audi's German headquarters issued a statement saying that it will "revise, document in detail, and resubmit for U.S. approval" parts of the software that controls the operation of the engine and its emission-control system.

The issues center around what are defined in agency rules as Auxiliary Emission-Control Devices (or AECDs) that temporarily allow the engine to exceed emission limits solely when required to protect the emission system from damage under specific operating conditions.

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For instance, starting a cold TDI engine and then immediately flooring the accelerator for 60 or 90 seconds--before catalytic converters in the emission aftertreatment system have fully warmed up--might require bypassing those systems for a short period of time.

The EPA allows these software routines, but they must be fully disclosed--and their operating parameters specified--during the car's initial emission certification.

Note that AECDs, which are legal if disclosed, differ from the "defeat device" software in VW's 2.0-liter TDI four-cylinder diesels, which kept emissions within legal limits only when it detected that the cars were undergoing emission testing.