The California Air Resources Board (CARB) discovered cheating software on popular Audi models that were rigged to produce lower CO2 emissions implicated in global warming during lab testing than in normal driving.

The device was installed on thousands of Audi A6 and A8 sedans and Q5 sport-utility vehicles that are equipped with the AL 551 automatic transmission and used in both diesel and gasoline-powered cars.

A German newspaper Bild am Sonnta on Sunday reported the newly discovered software was detected four months ago during tests by CARB, according to Automotive News.

The defeat device was not the same software that deactivated emission controls on Volkswagen and Audi diesel-powered vehicles to cheat tests for nitrogen oxides (NOx) emissions, which causes smog.

Bild am Sonnta said CARB officials caught Audi’s alleged cheating through lessons learned from the Volkswagen investigation.

The software, installed in the transmission, is designed to deliver low CO2 when the car starts up.

When the steering wheel is turned more than 15 degrees, such as in normal driving, the transmission switches to a different mode with higher CO2 levels.

It is only during laboratory testing conditions testing conditions that a vehicle has no steering inputs.

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Audi stopped using the software in May 2016, just before CARB discovered the new software device in an older model, Bild am Sonnt said, adding that the carmaker had suspended several engineers in connection with the matter.

Audi’s parent, the Volkswagen Group, is yet to reach an agreement with U.S. officials over the 3.0-liter diesel engine used in the Q5 SUV with the original NOx defeat device.

Volkswagen recently agreed to a $14.7 billion settlement with state authorities and owners of 475,000 two-liter diesel vehicles affected in the U.S.

However, this new allegation could raise fresh questions, not only in the U.S., but in Europe where regulations are stiffer on greenhouse gases than on nitrogen oxides.

Volkswagen insists that its software didn’t violate European law, and in Germany, Volkswagen hasn’t been charged with any breach of law.

Automotive News