Ford Motor Company admitted in a financial filing on Friday that it’s under investigation by the US Department of Justice over its internal emissions testing practices. The investigation is still in the “preliminary stages,” according to the automaker.

Notably, Ford says the investigation has nothing to do with the use of “defeat devices,” or software meant to deceive regulators, which was the issue at the center of Volkswagen’s Dieselgate scandal.

Ford announced its own investigation into the issue in February

Ford announced in February that it had launched an investigation into its own emissions testing practices after employees raised red flags over potential consistency problems. Those employees discovered Ford may have been miscalculating “road load,” which is a measurement of the forces — like aerodynamic drag or tire resistance — on a car when it’s traveling at a constant speed on smooth, flat ground. (Coming up with a lower road load figure in the lab versus in the real world, for example, could lead an automaker to believe its cars were getting better fuel economy and therefore emitting less pollution.)

The company said it hired law firm Sidley Austin to perform the investigation, and alerted the Environmental Protection Agency. Ford said Friday that it’s also now working with the California Air Resources Board to fix whatever problems might exist.

“The Department of Justice contacted us earlier this month to let us know that they had opened a criminal investigation,” the company said Friday in a statement to The Verge. “Ford is fully cooperating with the government, and we’ll keep them posted on what we’re finding through our investigation and technical review.”

Both Daimler (the parent company of Mercedes-Benz) and Fiat Chrysler Automobiles are also reportedly under criminal investigation regarding emissions, though like Volkswagen, they allegedly did use defeat devices to make some diesel cars appear cleaner to regulators. Daimler and Fiat Chrysler have faced civil charges, too. In January, Fiat Chrysler settled a civil case with the US Department of Justice for $800 million. The company also recalled 862,000 cars in March. Meanwhile, a class-action lawsuit against Daimler in the US recently got the green light to move ahead in a New Jersey court.