Fiat Chrysler Automobiles may have used illegal software for emission controls to get more than 100,000 trucks and SUVs through emissions testing, the EPA said Thursday.

The agency avoided dubbing that software "defeat devices," but it has asked FCA to explain up to eight auxiliary emissions control devices (AECD) in the engine's control software.

It found those routines while attempting to certify 2017 model year versions of the Jeep Grand Cherokee and Ram 1500 with the company's EcoDiesel 3.0-liter V-6.

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Failure to disclose the existence of those AECD software routines is itself a violation of the Clean Air Act, the EPA notes.

While the AECDs apparently allowed the vehicles to pass the legally mandated emission tests, the EPA says that in real-world use, the engines emitted more nitrogen oxides (NOx) than allowed under the Clean Air Act. 

More than 100,000 Jeep and Ram vehicles have been fitted with the EcoDiesel V-6, meaning they potentially include the undisclosed AECDs, the EPA said.


Since it is still waiting on FCA's responses to its detailed questions, the EPA hasn't released many details of the software in question.

The Italian-American automaker could face civil fines of up to $44,539 per vehicle, or over $4.4 billion.

But it's too early to speculate if the EPA will go after FCA executives or engineers, as it has done with Volkswagen. 

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The EPA says it worked with authorities in California and in Canada uncovering FCA's AECDs. 

In the wake of the Volkswagen diesel emission scandal, the EPA has focused on testing the real-world emissions of diesel vehicles offered for sale in the U.S.

Certification of several 2017 model-year diesel cars and light trucks has been held up, and a few such models have been withdrawn from the U.S. market.


“Once again, a major automaker made the business decision to skirt the rules and got caught,” California Air Resources Board Chairwoman Mary D. Nichols said in a statement.

“CARB and U.S. EPA made a commitment to enhanced testing as the Volkswagen case developed, and this is a result of that collaboration.”

In its news conference, the EPA said the affected vehicles are safe to drive and that owners should continue to use them. It also said that FCA dealers could continue to sell any remaining 2016 model-year EcoDiesel vehicles.

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In a statement issued shortly after the EPA's 11 am news conference, Fiat Chrysler said it was "disappointed" that the agency had chosen to issue a notice of violation.

It added:

FCA US has spent months providing voluminous information in response to requests from EPA  and other governmental authorities and has sought to explain its emissions control technology to EPA representatives. 

FCA US has proposed a number of actions to address EPA’s concerns, including developing extensive software changes to our emissions control strategies that could be implemented in these vehicles immediately to further improve emissions performance.

And, it said, the company "intends to work with the incoming administration to present its case and resolve this matter fairly and equitably."


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