The Audi A8, which only uses the AL 551 transmission in question. Photo Credit: Audi

The punitive California Air Resources Board (CARB) has figured out how Audi cheated on a particular run of “several hundred thousand” of their cars, according to a new report by the German newspaper BILD am Sonntag. This time we Americans have discovered a trick in the car’s software that relates to the steering wheel.


According to BILD am Sonntag’s new report this morning (view the link here, behind a paywall, or google around for a handful of other news sources re-covering the news including Reuters, Der Spiegel, Forbes and Automotive News), CARB figured out this software cheat months ago. Why we’re only hearing of this now, I do not know, and Bild am Sonntag cites no sources and we have as-yet no comment from CARB on the report, as Automotive News points out.

But the cheat reportedly works thusly, and it’s ingenious in its simplicity:

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.

The cheat was only implemented on cars with an automatic transmission with an internal designation AL 551. This appears to be a particular variant of the eight-speed unit Audi sources from transmission supplier ZF, set up for Quattro models. It apparently covers several hundred thousand vehicles under the cheat, according to Bild am Sonntag’s reporting. Diesel engines and gasoline engines are both affected here, and models involved include the Audi A8, the Audi Q5 as Forbes notes, as well as the Audi Q7 if my Wikipedia digging is correct.

This does not seem to be an issue on brand-new Audis, as Bild am Sonntag reports that Audi stopped using the software a few months before CARB figured it out while testing an unnamed older model, as Reuters notes.

This very much does not look good for Audi or for VW, which recently finished up its settlement with the U.S. Government and American VW owners. How this new wrinkle in the Dieselgate saga will play out is yet to be seen.