The US Justice Department has filed a civil lawsuit against Fiat Chrysler Automobiles (FCA) that accuses the company of using software to skirt emissions regulations. The lawsuit focuses on 2014–2016 model FCA diesel vehicles, including Jeep Grand Cherokee models and Dodge Ram 1500 trucks.

Reports of possible emissions cheating by FCA date back to April of last year. German outlet Bild am Sonntag reported that the country’s regulators suspected that, like Volkswagen, FCA might be cheating on emissions, but using a different approach. In Volkswagen’s case, the company used “defeat device” software that recognized when the car was being tested for emissions. The software changed, on demand, how the engine operated in order to meet those standards. The resulting scandal caused multiple resignations, criminal charges, and settlement payouts in the double-digit billions.

FCA, on the other hand, has been accused of making the engines of its diesel cars perform differently for the first 22 minutes after they were turned on — just a few minutes longer than German emissions tests last. In January, the EPA accused Fiat Chrysler of basically the same thing, adding that it believed FCA was also using software to shut off the emissions controls during normal driving.

The EPA asked the automaker to prove otherwise. At the time, Sergio Marchionne, CEO of FCA, said that people who compared Fiat Chrysler to Volkswagen were “smoking illegal material.” The Justice Department reportedly opened its investigation later that week.