Fiat Chrysler can begin selling diesel-powered versions of its 2017 Ram 1500 and Jeep Grand Cherokee vehicles, after receiving approval from state and federal environmental regulators.

The U.S. Environmental Protection Agency and California Air Resources Board have certified the vehicles, which will be powered by 3.0-liter diesel engines, FCA has announced.

FCA has been negotiating with the agencies since earlier this year to resolve concerns about the emissions control technologies in the vehicles. In May, the federal government sued FCA for using a defeat device to evade emissions testing.

FCA has applied updated emissions software calibration that won't affect the performance of the vehicles that has allowed them to address the agencies' concerns.

FCA will continue to work closely with the agencies to use a version of the modified software to update the emissions control systems of the 2014 to 2016 model-year Jeep Grand Cherokee and Ram 1500 diesel vehicles named in the notices of violation issued in January.

"The approvals announced today represent a significant step toward resolving the issues raised by EPA and ARB," said Sergio Marchionne, FCA's chief executive officer. "We appreciate the efforts of the agencies in working with us to achieve this milestone. We are anxious to build on this progress to make appropriate updates to the emissions control software in our earlier model-year vehicles."