U.S. engine maker facing largest Clean Air Act penalty ever over emissions test cheating accusations
In 2019, the U.S. Environmental Protection Agency (EPA) fined the engine maker Cummins Inc. a record-breaking $14 million for alleged Clean Air Act (CAA) violations. The EPA accused Cummins of selling about 550,000 heavy-duty diesel engines that were equipped with software designed to cheat emissions tests. The company had equipped its diesel engines with an auxiliary emissions control device (AECD) that corresponded with a piece of software making it appear as if the engine met emission standards. The software would adjust the engine systems during lab tests in order to reduce emissions but then deactivate them for on-road use, which significantly increased emissions. This type of tampering violation of the CAA is known as a Defeat Device. In addition to the fine, the EPA required that Cummins repair or replace all engines equipped with this illegal AECD.