FRANKFURT -- A U.S. regulator found software in some Audi vehicles that lowered their CO2 emissions if it detected they were being used under test conditions, German newspaper Bild am Sonntag reported.
The California Air Resources Board (CARB) discovered the software in an Audi with an automatic transmission last summer, the German weekly newspaper said, without citing any sources.
CARB had no immediate comment and Audi was not immediately available for comment on the report.
The device was also used in diesel and gasoline-powered cars in Europe.
The device was not the same as the software that deactivated emission pollution controls to cheat tests for NOx emissions. Volkswagen Group's admission that it had installed the software rigged to defeat NOx tests on more than 11 million diesel vehicles sold worldwide triggered the deepest business crisis in the automaker's history. Audi, the main contributor to VW group profit, has also admitted its 3.0-liter V-6 diesel engine was fitted with NOx emissions-control software.
Bild am Sonntag said the CO2-cheat software discovered by CARB was installed in vehicles with automatic transmissions with the internal code name AL 55. The software detected whether a car's steering wheel was turned. If it was not, indicating laboratory testing conditions, the software turned on a gear-shifting program which produced less carbon dioxide than in normal road driving. If the wheel was turned in any direction by more than 15 degrees, the program was switched off, the paper said.
The findings made over the summer apply to cars including the Audi A6 and A8 sedans and the Q5 SUV, the newspaper said.
Audi stopped using the software in May 2016, just before CARB discovered the manipulation in an older model, the paper said, adding that the carmaker had suspended several engineers in connection with the matter.
Bild am Sonntag said a spokesman for Audi had declined to comment, citing ongoing talks with U.S. and California regulators on a proposed fix for cars with 3.0-liter engines.
Bloomberg and Automotive News Europe contributed to this report