Volkswagen has admitted that some Audis came with emissions-cheating software after American authorities discovered a new trick.
Two weeks ago, it was reported that the California Air Resources Board (CARB) had discovered that some Audis with automatic transmissions could detect when they were undergoing testing and would run in a way that lowered emissions.
The trick applies to a particular run of 'several hundred thousand vehicles', according to a report in a German newspaper, and now Volkswagen has officially confirmed the software was in place.
According to Reuters, Volkswagen, which owns Audi, said: "Adaptive shift programs can lead to incorrect and non-reproducible results." It has made 'technical information' available to the Federal Motor Vehicle Authority in Germany.
CARB discovered that on start-up the Audis would be in a 'low CO2' mode, which made the transmission shift up at lower revs to keep emissions low. However, once the wheel was turned more than 15 degrees, this mode would be disengaged and a normal transmission program would start.
Because traditional emissions testing takes place on a 'rolling road', there is no need for the wheels to turn, but in the real world drivers would generally exceed the 15-degree limit almost immediately.
Steve Berman, managing partner of law firm Hagens Berman, said: "Throughout the year-long Dieselgate scandal, Audi chose to continue to deceive consumers across the country with yet another emissions-cheating device installed in even more of its vehicles.
"This kind of flagrant disregard for federal environmental regulations and consumers' expectations is unacceptable, and we intend to hold Audi to the law on behalf of those who overpaid for Audi's non-compliant, polluting cars."
Audi is also under investigation for a different 'defeat device' following Volkswagen's 'Dieselgate' scandal.