A new lawsuit claims that Ford cheated on emissions tests with about 500,000 heavy-duty pickup trucks.

The lawsuit, from firm Hagens Berman, alleges that diesel-powered Ford F-250 and F-2350 trucks sold from 2011 to 2017 can spew up to 50 times the legal limit of nitrogen oxide pollutants while the vehicle’s onboard diagnostic software indicates that the emissions controls are working correctly.

The suit claims that Ford worked with German supplier Robert Bosch GmbH to come up with the diesel cheating software. Bosch is named in diesel cheating suits against multiple automakers, including VW, Fiat Chrysler, and GM. A total of 58 alleged violations are named included false advertising and racketeering claims.

READ MORE: Ram Diesel Owners Suing FCA, Cummins Over Inflated Fuel Economy

Specifically, the software allowed Ford to reverse the order of the exhaust treatment, putting catalytic reduction before the diesel particle filter. This should have resulted in the truck having to burn off the collected particles, but according to the lawsuit, they were released in the exhaust.

In order to meet regulations, Hagens Berman says that the Ford Super Duty diesels will probably require modifications that will reduce power, torque and or fuel economy.

Both Ford and Bosch refused to comment on the story when contacted by Bloomberg.

UPDATE: Ford has released an official statement on the lawsuit. “All Ford vehicles, including those with diesel engines, comply with all U.S. EPA and CARB emissions regulations. Ford vehicles do not have defeat devices. We will defend ourselves against these baseless claims.”

[Source: Bloomberg]