VW V6 TDI
Michael Taylor24 Nov 2015
NEWS

Dieselgate: Volkswagen finds a fix

Audi announces CO2 fix for 3.0 TDI engines in US as solution for VW 1.6 TDI emissions cheat also emerges

Audi has today announced it will fit revised emissions control software to more than 85,000 Volkswagen Group vehicles with 3.0-litre V6 diesel engines deemed by regulators earlier this month to have violated US environmental laws.

The move affects Audi A6, A7, A8, Q5 and Q7 models (since model year 2009) and, since MY2013, the Volkswagen Touareg and Porsche Cayenne, all of which remain subject to a voluntary 'stop-sale' order in the US until further notice.

Audi says no 3.0 TDI vehicles are affected by the issue in Australia, where a variety of four-cylinder diesel VW, Audi and Skoda vehicles have been pulled from sale and almost 100,000 recalled following the Dieselgate emissions-cheating scandal, which prior to the V6 diesel's involvement affected about 11 million vehicles globally.

Audi will submit a new US government emission certification application for the revised software, which will be fitted once approved by the US Environmental Protection Agency (EPA) and California’s Air Resources Board (CARB).

This follows a November 2 'notice of violation' that informed Audi "that AECDs (Auxiliary Emission Control Devices) were not sufficiently described and declared in the application for US type approval.

"Audi has confirmed that three AECDs were not declared in the context of the US approval documentation," it said. "One of the AECDs relates to the temperature conditioning of the exhaust gas cleaning system.

"The other two AECDs are for the avoidance of deposits on the Ad-Blue metering valve and of HC poisoning of the SCR catalyst with unburnt hydrocarbons. One of them is regarded as a defeat device according to applicable US law. Specifically, this is the software for the temperature conditioning of the exhaust-gas cleaning system.

"Audi has agreed with the environmental authorities on further steps of cooperation in which the concrete measures to be taken will be specified. The company has committed to continue cooperating transparently and fully. The focus will be on finding quick, uncomplicated and customer-friendly solutions."

Audi estimates the cost of the US 3.0 TDI software fix will be in the "mid-double-digit millions of euros" range, which is likely to be far less than the hardware retrofits expected to be needed by 482,000 2.0 TDI diesel vehicles sold by Volkswagen of America with illegal 'defeat device' software.

Meantime, a new mass air flow sensor worth about €10 could finally be enough to bring Volkswagen’s 1.6-litre diesel engines into line with EU5 emissions rules.

The embattled German car-maker has submitted to European Commission demands to prove to them they have a fix that works, insisting that fitting the new part into the air-intake system of its 1.6-litre turbo-diesel EA188 four-cylinder engines, combined with software upgrades, will bring the motors into compliance.

If the EU agrees, it would be a huge fillip for Volkswagen, which had been speculating that the 1.6-litre cars would need costly hardware changes, including finding a place to fit an AdBlue tank. There were initial fears that the costs could balloon out beyond €150 a car and dealers would need to train and employ squadrons of technicians to fit additional urea tanks.

The news comes as Volkswagen comes under more legal scrutiny at home, with the public prosecutor in Braunschweig (Brunswick) opening a new criminal investigation into the company last week. The investigation will centre on its CO2 cheat, which Volkswagen admitted to two weeks ago and is separate from its Dieselgate NOx-cheating investigation.

The 1.6-litre four-cylinder diesel engine provides the bulk of the 11 million Volkswagen’s affected worldwide by its cheating scandal, where it used sneaky software coding to get around NOx emissions regulations in the US, Europe and other countries that adopted EU rules, including Australia.

“The sensor goes into the air intake and sits in the air flow and it also will govern the air swirl as it enters the engine,” a Volkswagen source said yesterday.

The 1.6-litre engine was not affected by the original US Dieselgate discoveries, as it has never been sold in North America, so only has to meet the 180mg/km NOx limit set by the EU5 regulations.

Instead, the 2.0-litre version of the same engine was caught in real-world testing and Volkswagen sources insist that bringing it into line with the EU5 and EU6 laws will only involve mostly software updates. It’s a different story in North America, though, where the maximum allowable NOx emissions are roughly half Europe’s current EU6 limit of 80mg/km.

Its plan for the US involves a larger exhaust system with a series of traps to capture NOx, then burn it off when the engine is working harder and hotter. It is believed that the plan also involved some models receiving the AdBlue urea injection system, which will be costly and laborious.

In both cases, Volkswagen sources admitted there would be negative impacts on fuel consumption and performance, though they would not be drawn on specifics.

Besides capacity, the major difference between the engines is that while they both use the Bosch EDC 16 engine management computer, the smaller engine uses a fuel-delivery system from Continental while the 2.0-litre uses a system sourced largely from Bosch.

The fix raises a major question about why Volkswagen would take such a risk to cheat on the emissions for the sake of €10 per car.

Full run down of Dieselgate stories here on motoring.com.au

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Written byMichael Taylor
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