Talks appear to be breaking down between the U.S. government and Fiat-Chrysler Automobiles over the automaker's alleged use of emission defeat devices. Now, according to Bloomberg, the U.S. Department of Justice is preparing to sue the automaker if talks fail to resolve the issue.

Previously, both sides were said to be nearing an agreement, though things have reportedly gone south. The lawsuit could come as soon as this week if discussions continue to erode between the automaker and the EPA. As far as U.S. officials are concerned, FCA has not been able to fully explain the purpose of its diesel vehicles' behavior. FCA has been accused of cheating emission tests by installing software in 104,000 Jeep Grand Cherokees and Ram 1500 pickups to improve performance and reduce pollution controls. The EPA said that some of the controls “appear to cause the vehicle to perform differently when the vehicle is being tested than in normal operation and use."

Under the Clean Air Act, auxiliary emission control devices (AECDs) are legal, but FCA failed to disclose the presence of eight such controls in both the 2-14-2016 Jeep Grand Cherokee and Ram 1500 with the 3.0-liter V-6 diesel engine.

“In the case of any litigation, FCA US will defend itself vigorously, particularly against any claims that the company deliberately installed defeat devices to cheat U.S. emissions tests,” Fiat Chrysler said in a statement. “The company believes that any litigation would be counterproductive to ongoing discussions with the U.S. Environmental Protection Agency and the California Air Resources Board.”

There's one stark difference between the FCA and Volkswagen's widespread diesel emission scandal: While VW openly admitted to installing a "defeat device" to pass emission tests, FCA and regulators seem to disagree on what the AECDs are capable of legally doing. The U.S. isn't toying around and could slap FCA with potential penalties of up to $44,539 per affected vehicle. FCA argues that the AECDs are there to protect the engine in high-load conditions such as towing.

The report states an agreement may come sooner rather than later to avoid prolonged litigation. Should it happen, it will likely come as a contrast to what FCA CEO Sergio Marchionne has said in the past.

“We have no defeat devices. We may have made mistakes [on diesel software disclosure] but never tried to break any rule.”

FCA has said the issue can be fixed with a simple ECU reflash. At this point, that apparently won't do the trick for the government.