Fiat Chrysler's US unit has pleaded guilty and agreed to pay $300 million in penalties in the long-running case over the automakers efforts to cheat diesel emissions tests, the US Justice Department announced on Friday.
The European carmaker was accused of installing "defeat devices" on cars to evade emissions standards and in January 2019 agreed to a $515m US civil settlement.
FCA has now admitted guilt to one criminal felony count of conspiracy to defraud the US, commit wire fraud and violate the Clean Air Act, according to the Justice Department statement.
"FCA US engaged in a multi-year scheme to mislead US regulators and customers," assistant attorney general Kenneth Polite Jr said.
"The guilty plea demonstrates the department's dedication to prosecuting all types of corporate malfeasance and holding accountable companies that seek to place profits above candour, good corporate governance, and timely remediation."
US officials said FCA's EcoDiesel Ram 1500 and Jeep Grand Cherokee models for years 2014 to 2016 were built with software designed to operate differently during emissions tests compared with real-world conditions, meaning the vehicles spewed nitrogen oxide and other pollutants at "much higher" levels than allowed.
In addition to the finds, the auto giant also recalled and repaired more than 100,000 diesel vehicles sold in the US at a cost about $185m.
But that agreement did not lift the criminal proceedings. Formal sentencing is scheduled for July 18 in the criminal case. Three employees also have been charged and are awaiting trial.
The settlements followed the Volkswagen scandal over defeat devices that has spawned billions of dollars in fines, civil settlements and criminal prosecutions of former executives with the German giant.
But unlike the Volkswagen case, the Justice Department said FCA did not initially admit there was anything wrong with their vehicles saying the issue was not intentional.
FCA parent company Stellantis said it had set aside about $300m last year for this litigation process.