GM Accused of Using VW-Like Defeat Devices

General Motors was sued for allegedly putting defeat devices in its trucks to beat emissions tests, the sixth automaker accused of diesel cheating since 2015, when Volkswagen admitted to installing software to bypass pollution rules.

Owners or lessees of more than 705,000 GM Duramax diesel trucks filed a class-action lawsuit Thursday, claiming GM installed multiple such devices in two models of heavy-duty trucks from 2011 to 2016. The 190-page complaint is littered with 83 references to VW, and asserts that the environmental damage caused by each truck could surpass that of the German automaker’s vehicles.

GM’s cheating allowed its trucks to pass U.S. inspections, even while they spewed emissions two to five times the legal limit under regular driving conditions, according to the complaint filed in Detroit federal court.

GM spokesman Tony Cervone said the lawsuit is without merit.

The complaint underscores questions about the credibility of diesel technology. The allegations against VW have cost it $24.5 billion in fines, penalties and potential buybacks across North America.

In the case of Fiat Chrysler Automobiles, drivers filed a class action suit alleging VW-like cheating on diesel emissions tests and shortly after, U.S. prosecutors and regulators were investigating as well. Daimler is the target of a German probe related to diesel emissions, and French carmakers Renault and PSA Group are both being investigated in their home country.

“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. Berman has also represented drivers and dealerships against VW and in Fiat Chrysler’s ongoing litigation. “These GM trucks likely dumped as much excess poisonous emissions into our air as did the cheating Volkswagen passenger cars.”

Excessive emissions from the GM vehicles exposed the general public to noxious levels of smog, according to the complaint. Diesel engines, while more fuel efficient, produce greater volumes of nitrogen oxide pollutants, or NOx. During on-road testing, the diesel trucks polluted at levels beyond legal limits and higher than their gasoline counterparts, according to the complaint.

To meet environmental standards, the Chevrolet Silverado Duramax and GMC Sierra Duramax diesel trucks will probably require modifications that would reduce power, torque and fuel efficiency, according to the complaint.

Technology provider Robert Bosch, which was named as a co-defendant by consumers who sued VW, is also defendant in the GM case, described in the complaint as “an active and knowing participant in the scheme to evade” emissions standards.

A Bosch representative didn’t immediately respond to a request for comment on the GM suit.

Representatives of the Justice Department and the Environmental Protection Agency didn’t immediately respond to requests for comment.

GM erased gains in early trading and fell after the lawsuit was filed. The stock closed down 60 cents, or 1.8 percent, to $32.60.