The Justice Department on Tuesday indicted three former Fiat Chrysler engineers for their role in designing engine-control systems that allowed some of its diesel vehicles to cheat on emissions tests.
The indictment, in the U.S. District Court in Detroit, was handed down by a grand jury in March and unsealed Tuesday. Fiat Chrysler merged with Peugeot SA this year and is now known as Stellantis.
The engineers are Emanuele Palma, a diesel-calibration manager in Auburn Hills, Mich., who had been previously charged by federal prosecutors; Sergio Pasini, the head calibration engineer who supervised Palma, who lives in Italy; and Gianluca Sabbioni, a technical director, also from Italy.
The indictment accuses the engineers of developing software -- known inside the company as "T-engine" -- that could increase the use of emissions-control systems when vehicles were undergoing emissions testing and could decrease them when driven by customers in real-world conditions.
Lowering the controls made the vehicles appear more fuel-efficient, an achievement that the company highlighted when selling the cars. The software was used in 3-liter diesel engines that were available on the Jeep Grand Cherokee and Ram 1500 pickups. Fiat Chrysler marketed the models as "clean" diesel and "best-in-class" fuel economy.
In 2019, Fiat Chrysler agreed to settle emissions-cheating allegations with the federal and state governments in a deal that was estimated to cost the company nearly $800 million.