How Audi cheated emissions tests: if (steering) then (pollute)


A report in BILD am Sonntag claims that the California Air Resources Board (CARB) has uncovered the secret test that Audis were programmed to perform to determine whether to pollute like crazy or to pretend that they were low-polluting, legally compliant vehicles.

The test was deceptively simple: the car starts in a "low CO2" mode, then, if the steering wheel is turned more than 15 degrees, the program ends and the engine kicks into a high-emission, high-fuel-efficiency mode that made Audis very cheap to drive, unless you count the cost of losing every coastal city in the world by the end of the century.

When the Audi starts up, its transmission engages a ‘low CO2' program, shifting gears in such a way as to keep engine revs and emissions artificially low. If the steering wheel is turned more than 15 degrees, the car deactivates the program and shifts in its normal, more pollutant fashion that burns more gas and produces more CO2.

Audi figured that the only time the car would run with the steering wheel never moving would be in a lab, on a test bed. This is a similar philosophy to the classic ‘dyno mode’ cheat that kicked off Dieselgate. It’s so simple, and apparently it was enough to get Audis to pass emissions tests in lab situations they might have never passed in real world conditions.

Lenkrad-Trick | So schummelte Audi bei CO² [BILD am Sonntag]

America Figured Out A New Way Audi Cheated on Emissions Testing: Report [Raphael Orlove/Jalopnik]

Notable Replies

  1. Enkita says:

    VAG seems to have gone massively downhill. But I am unsurprised.
    Back on around 2007 when there was a lot of talk of clean diesel, Toyota engineers said that the reason they had gone for hybrid was because they did not believe diesel could be cleaned up enough to meet future emissions. Despite having started my career in Diesel R&D, by then I was getting worried about particulates, and my next car was a Prius, the first non-Diesel I had in many years. The Prius wasn't satisfactory for various non-powertrain related reasons, but I still have two gasoline Toyotas.
    I have always respected Toyota and Honda engineering, and if they thought it wasn't really possible they had to be listened to. I suspect that the Germans got all excited about adding urea and then found out just how much would be needed - I would not be surprised if some of their urea-additive cars stop adding the urea outside test mode.
    Recent spark ignition engines have been getting competitive with Diesel on carbon emissions, and I don't expect them to die out soon. But I do expect gathering pressure to get rid of Diesel vehicles. The future may be LNG or even hydrogen, but currently EVs are not going to work at significant scale unless batteries can get off lithium and perhaps onto an aluminium based technology.
    The Germans seem to have backed themselves into a corner, depending on Diesel as a differentiating technology and with very expensive and complicated spark ignition engines to get enough power with low emissions in the US market. The future is going to be technically interesting but I suspect VAG may not be as big a player in it.

  2. If (steering) then (pollute) is a pretty elegant algorithm for checking for emissions testing.


  3. I wonder how long the engineers have been holding their breaths waiting for this to be discovered after the initial Dieselgate findings?

  4. Are you sure they weren't just holding their breaths because of the extra pollution?

  5. It's not 'holding your breath', it's 'test mode respiration'. VW engineers switch over to anaerobic metabolism when they detect test conditions; then revert to aerobic metabolism in the field.

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