The United States on Thursday charged Fiat Chrysler with using software on its trucks to evade emissions standards on about 104,000 vehicles.

The Environmental Protection Agency said the undisclosed software on the 2014 to 2016 models of Grand Cherokees and Dodge Ram 1500 trucks sold in the United States allowed the vehicles to emit more nitrogen oxides than permitted.

The company already is facing two class-action lawsuits over use of the defeat software.