The Department of Justice, the Environmental Protection Agency, the California Air Resources Board, and the California Attorney General’s Office are the government entities involved in the matter, according to the company. The engine maker said that a review of the issue started in 2019. It has already recalled model year 2019 RAM 2500 and 3500 trucks and has started a recall of 2013 through 2018 RAM 2500 and 3500 trucks.

Separately, the DOJ said that Cummins has agreed to pay a roughly $1.68 billion penalty to settle claims that it breached the Clean Air Act by installing certain devices on “hundreds of thousands” of engines to bypass emissions tests. Under the act, vehicle and engine makers are required to make sure that their products comply with applicable emission limits.

This would be the largest civil penalty “we have ever secured under the Clean Air Act, and the second largest environmental penalty ever secured,” Attorney General Merrick Garland said in a statement. “The types of devices we allege that Cummins installed in its engines to cheat federal environmental laws have a significant and harmful impact on people’s health and safety.”

The company’s shares were down 3.1% in Friday afternoon trade.

“Cummins conducted an extensive internal review and worked collaboratively with the regulators for more than four years,” it said. “The company has seen no evidence that anyone acted in bad faith and does not admit wrongdoing.” The company said it looks forward to “obtaining certainty,” as it has already addressed many of the issues involved.