The $14.7 billion diesel-emission settlement among Volkswagen and regulatory agencies required VW to buy back or modify almost half a million TDI vehicles from model years 2009 through 2015.

While the buybacks have received the most attention—and most owners are expected to take them—the company also submitted plans to modify its diesels to meet the emission limits that their "defeat device" software ignored.

Now the first such modification has been approved both by the EPA and the powerful California Air Resources Board.

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Volkswagen had proposed such modifications well before the settlement was announced last October.

Those agencies have been reviewing the materials it submitted and conducting "extensive testing of eight vehicles equipped with the Proposed Emissions Modification," they said.

The Environmental Protection Agency announced the approval yesterday in a release, which linked to a 5-page approval letter issued jointly by the two agencies.

2015 Volkswagen Passat TDI

2015 Volkswagen Passat TDI

A "two-stage" modification will reduce emissions of nitrogen oxides (NOx) to the limits specified under the so-called Tier 2, Bin 5 rules in effect since January 1, 2008.

According to the EPA's announcement, VW submitted test data showing that the modification "will not affect vehicle fuel economy, reliability, or durability," and the two regulatory agencies confirmed that.

The modifications that have been approved apply only to TDI diesel cars from the 2015 model year, which were fitted with a new "EA288" 2.0-liter 4-cylinder turbodiesel engine.

Those models are:

  • 2015 Audi A3 TDI
  • 2015 Volkswagen Beetle TDI and Beetle Convertible TDI
  • 2015 Volkswagen Golf TDI and Golf SportWagen TDI
  • 2015 Volkswagen Jetta TDI
  • 2015 Volkswagen Passat TDI

2015 Volkswagen Golf TDI

2015 Volkswagen Golf TDI

No other Volkswagen TDI diesel model from the 2009 through 2014 model years is eligible for this modification.

Earlier Volkswagen diesels from 2008 and before are not affected by the VW diesel emission scandal.

The next step is that VW Group must inform all eligible owners of the affected vehicles within 10 days that the modification option is available as well as the buyback.

CHECK OUT: Final VW diesel settlement signed; buyback offers to start soon (Oct 2016)

After the EPA announcement, Volkswagen issued the following statement:

Today [we] received regulatory approval for a two-phase emissions modification for affected 2.0L TDI vehicles with Generation 3 engines, this is an important step.

We will now notify eligible customers in the United States that they can receive phase one of this modification at dealerships free of charge as soon as possible.

Volkswagen continues to work closely with EPA and CARB to reach an agreement on approved emissions modifications for other affected 2.0L TDI vehicles as quickly as possible.

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