General Motors has been hit with a class-action lawsuit claiming defeat devices had been placed in hundreds of thousands of its diesel trucks.

The class action suit was filed Thursday in the Detroit federal district court on behalf of owners and lessees of more than 705,000 Duramax-engined GMC and Chevy trucks. It asserts GM cheated on emissions testing in two models of heavy-duty pickup trucks from 2011 to 2016.

The Duramax V8 diesel engine is available as an option for Chevy Silverado and GMC Sierra pickups. It offers more torque and horsepower for hauling and towing trailers.

“These claims are baseless and we will vigorously defend ourselves,” GM said. The automaker said its diesel Silverado and Sierra pickups comply with all U.S. Environmental Protection Agency and California Air Resources Board emissions regulations.

Excessive emissions from the GM vehicles exposed the public to noxious levels of smog, according to the suit.

“GM claimed its engineers had accomplished a remarkable reduction of diesel emissions,” attorney Steve Berman, a managing partner at Hagens Berman, said in the complaint. “These GM trucks likely dumped as much excess poisonous emissions into our air as did the cheating Volkswagen passenger cars.”

The 190-page complaint includes 83 references to Volkswagen, and claims that the environmental damage caused by each GM truck could be more damaging than that of VW’s diesel vehicles.

Berman has also represented drivers and dealerships against VW and Fiat Chrysler Automobiles.

GM has become the sixth global automaker being investigated or sued for allegedly installing defeat devices to beat emission tests in diesel vehicles. Along with investigations and suits against VW and Fiat Chrysler, Daimler is the target of a German probe and Renault and PSA Group are both being investigated in their home country of France.

Supplier Robert Bosch GmbH has also been drawn into the suit for its software in GM’s diesel engine.

Bosch was described in the complaint as “an active and knowing participant in the scheme to evade” emissions standards.

“Bosch takes the allegations of manipulation of the diesel software very seriously,” Linda Beckmeyer, a company spokeswoman, said in an email. “Bosch is cooperating with the continuing investigations in various jurisdictions, and is defending its interests in the litigation.”

Bosch was named a co-defendant by consumers who had sued VW.

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This is the second class-action suit against GM alleging emissions cheating.

Last year in July, a class-action lawsuit was filed in California by the law firm of Hagens Berman Sobol Shapiro, claiming that GM has been using emissions-cheating software. That results in more-than-allowed NOx to escape the tailpipe, according to the suit.

The Seattle law firm is asking GM to pay Cruze Diesel owners back the $2,000 premium they paid for their cars as well as punitive damages.

GM has disputed the claims made in the class-action lawsuit.