Lawyers representing owners of 2007-2012 2500 and 3500 Dodge Ram trucks filed a class-action lawsuit against Fiat Chrysler Automoblies and Cummins Inc accusing them of cheating on diesel emissions tests.

Since October, Fiat and Cummins have been tied up in a recall of 130,000 2013-15 model year 2500 Ram pickup trucks equipped with a 6.7L Cummins diesel engines that were found to have moisture that could lead to the deactivation of the selective catalyst reduction system, causing excess nitrogen oxide emissions that could exceed U.S. pollution limits. 

According to the lawsuit, and Reuters, Steve Berman, the lawyer who filed the suit, said the emissions catalysts are not durable and do not meet emission standards, and that at times emissions are nearly 10 times legal limits.

Fiat and Cummins Inc both said, according to Reuters, that they will "fight" against the lawsuit that alleges they "conspired to knowingly deceive consumers and regulators of illegally high levels of diesel emissions in their vehicles." 

Fiat Chrysler said in a statement, according to Reuters, it "does not believe that the claims brought against it are meritorious" and the company "will contest this lawsuit vigorously."

Cummins spokesman Jon Mills told Reuters that the lawsuit "has no merit. We are obviously disappointed in the effort to tarnish our image and we plan to vigorously defend ourselves."

In addition, Fiat Chrysler sued Cummins for the $60 million it spent to keep 42,000 trucks within emission limits. 

Cummins counter-sued, saying Fiat Chrysler would not cooperate in the recall "for one reason - money" and said the automaker was "holding both Cummins and its own customers hostage," according to Reuters. 

(Original reporting by David Shepardson; Editing by Sandra Maler)