Dieselgate: Audi, Porsche and VW to fix V6s

Despite initially denying their bigger engines had joined four-cylinder diesels on the Dieselgate cheat sheet, Audi, Porsche and Volkswagen have now been ordered to fix their 3.0-litre V6 turbo-diesels within 45 days.

The California Air Resources Board (CARB) yesterday ordered the three car-makers to modify more than 15,000 cars and SUVs sold with the engines since 2009, and the US Environmental Protection Agency is set to follow suit with a nationwide order.

The three companies will have to resubmit their vehicles for certification in the US, as with the early stages of the four-cylinder Dieselgate crisis, but the Volkswagen Group is yet to confirm any ramifications for Europe or other markets.

While a Volkswagen spokesman said it was still deliberating over an official statement and would not speak off the record, CARB said its order was in response to Audi’s admission that its V6 engines had three “auxiliary control devices” fitted to them.

CARB had teamed with the EPA and tested the engines in three laboratories across the US and Canada before issuing a Notice of Violation on the V6s, joining the EA 189 four-cylinder diesels on the naughty step.

The Californian sales from 2009 to 2015 soaked up only 15,000 cars, out of 85,000 across the US, but in the bitterly turbulent wake of Dieselgate, CARB put the rest of the Volkswagen Group’s engines through the wringer anyway.

Audi this week admitted that one of the three auxiliary control devices could be considered a “defeat” device, just like the software code in the EA 189 four-cylinder diesels that only switched on all the emissions cleaning tools when it was in a laboratory.

The admission put Audi out in front of Volkswagen and Porsche, which both denied they had done anything wrong in a sneakily worded statement, saying: “no software has been installed in the 3-liter V6 diesel power units to alter emissions characteristics in a forbidden manner”.

But Audi’s admission and CARB’s order will cost the Volkswagen Group more than $US10 million to fix, even though it will exclusively be software focused.

“Audi will revise, document in detail, and resubmit for US approval certain parameters of the engine-management software used in the V6 TDO 3 liter diesel engine,” Audi said in a statement yesterday.

“That is the result of the discussions held between a delegation from Audi AG and the US Environmental Protection Agency and the California Air Resources Board.

“The updated software will be installed as soon as it is approved by the authorities. The three brands, Audi, Porsche and Volkswagen, are affected.

“Audi estimates that the related expense will be in the mid-double-digit millions of euros.”

The EPA and CARB found the new cheat code in its ongoing tests of all passenger-car diesel engines in the wake of the Dieselgate scandal.

Damningly, it alleged that software code in the engine control module of the 3.0-litre engines used similar “tells” to the EA189 to figure out it was being tested in a laboratory, then switched on emissions-cleaning protocols that switched off at 1371 seconds -- just one second after the initial phase of the FTP 75 Federal emissions test ended. It then transitions to its normal mode.

It alleged that it worked by turning on “low NOx temperature conditioning” mode, switching on a range of tweaks including changing the ignition timing, the rate of exhaust gas recirculation and the fuel pressure in the common-rail injection system.

The EPA’s Notice of Violation insisted the changes lowered the engine-out NOx levels and accelerated the heating up of the exhaust’s selective catalytic reduction (SCR) system.

Audi immediately withdrew the diesel versions of its A6, A7, A8, Q5 and Q7 from sale in North America while it investigated the EPA’s findings, while Porsche pulled the Cayenne Diesel and Volkswagen paused the Touareg diesel.

Audi’s statement then offered more insight into how the V6 “defeat” code worked, admitting it was part of the “warm-up strategy”, making it a different type of cheat to the EA 189 2.0-litre four-cylinder Dieselgate motors.

“One of the AECDs (Auxiliary Control Devices) relates to the temperature conditioning of the exhaust-gas cleaning system,” Audi confirmed, without quoting a specific spokesman.

“The other two AECDs are for the avoidance of deposits on the Ad-Blue metering valve and of HC (hydrocarbon) poisoning of the SCR (Selective Catalytic Reduction) 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.”

If the software fix is approved by both CARB and the EPA, even this relatively simple tweak, together with the retesting and the recall of about 85,000 cars, will cost more than $US50 million, Audi admitted. The 2.0-litre turbodiesel Dieselgate cars in the US will need both hardware and software overhauls and will cost an order of magnitude more than that.

“Audi has agreed with the environmental authorities on further steps of cooperation in which the concrete measures to be taken will be specified,” Audi said.

“The company has committed to continue cooperating transparently and fully. The focus will be on finding quick, uncomplicated and customer-friendly solutions.

“The voluntary sales stop for models with the V6 TDI diesel engine, which the three affected Group brands had provisionally decided upon, has been extended until further notice.”

The Volkswagen Group submitted its proposed fix for the 2.0-litre TDI Dieselgate cars to the US EPA last Friday, but has not released details of the upgrades (though they are expected to involve both hardware and software).

It also presented the German Federal Motor Transport Authority (KBA) with a proposal to fix 1.6- and 2.0-litre Volkswagen Group cars sold in Europe, with a "technical solution" for the 1.2-litre three-cylinder TDI expected to comprise a software update to be announced in Germany at the end of this month.

Likely to be the same fix applied to Australian VW, Audi and Skoda vehicles when a local recall commences early next year, the 2.0-litre TDI modification involves only a software update, while the 1.6-litre TDI fix includes a new “flow transformer” grille on the air-filter, a new mass air flow sensor and software changes that will cost the company around €10 a car.

The 1.6-litre repair will take up to an hour and the 2.0-litre work will require less than half an hour of labour, said VW, which will begin recalling the vehicles in Europe from January.

In both cases, Volkswagen says its target is "no adverse effects on fuel consumption and performance".

"The technical measures developed for the EA 189 diesel engines affected have been presented to the Federal Motor Transport Authority. Following an intensive examination, these measures have been ratified by the Federal Motor Transport Authority. This means that there is now clarity regarding the correction of the irregularities for the majority of vehicles affected," said VW.

"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 objective for the development of the technical measures is still to achieve the applicable emission targets in each case without any adverse effects on the engine output, fuel consumption and performance. However, as all model variants first have to be measured, the achievement of these targets cannot yet be finally confirmed.

"Based on these technical measures accepted by the Federal Motor Transport Authority, the necessary service concepts are currently being developed for the EU28 markets concerned . The aim is to implement the required technical update in the first vehicles during a recall from January 2016. According to the current assessment, all measures in the course of the recall for all engine variants will extend over the whole calendar year 2016."

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