VW details 1.6L, 2.0L TDI emissions fixes for Euro-spec cars

The 2.0-liter EA189 engines will only need a software fix, while the 1.6-liter will get a minor hardware refit to improve MAF accuracy.

Volkswagen has detailed its proposed fix for non-compliant 1.6- and 2.0-liter EA189 engines in European markets.

The 2.0-liter TDI mills will simply require a software update to reduce NOX exhaust emissions. The new engine-management programming is claimed to have no adverse effect on fuel consumption or performance.

The 1.6-liter oil burner requires a hardware refit along with a software update to better optimize diesel combustion. Service technicians will install a mesh "flow transformer" in front of the air mass sensor, calming the swirled air flow to significantly improve measuring accuracy.

"Thanks to advances in engine development and improved simulation of currents inside complex air intake systems, in combination with software optimisation geared towards this, it has been possible to produce a relatively simple and customer-friendly measure," the company said in a statement.

The company is working to implement technical resolutions that bring emissions back into compliance without any adverse effects on engine output, fuel consumption or performance.

"However, as all model variants first have to be measured, the achievement of these targets cannot yet be finally confirmed," the statement added.

The company has not yet finalized a fix for the 1.2-liter Euro-spec engines. A proposed fix for the US-market 2.0-liter mills has not yet been made public, pending approval from the Environmental Protection Agency and the California Air Resources Board.

Previous reports suggest VW will be forced to implement more complex and costly hardware modifications for the US-spec 2.0-liter TDI engines. EPA regulations place much tighter restrictions on nitrogen-oxide output, requiring a fleet average below 0.04g/km. In contrast, Euro5 emissions regulations cap output at 0.18g/km for individual vehicles.

Most of VW's offending 2.0L vehicles were put onto the US market without urea-injection selective catalyst reduction (SCR) technology. SCR systems significantly reduce NOx output, however such a retrofit is much more complicated than the air-intake mod chosen for the Euro-spec cars. VW presumably would have to install new exhaust components, a liquid tank to hold the AdBlue urea fluid, and extensive plumbing to make it work.

VW is expected to announce details of its US-market fix plan in the coming weeks.

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