Diesel woes continue as General Motors is accused of emissions cheating

2016 Chevrolet Silverado HD

The Volkswagen diesel scandal has brought increased scrutiny on automakers peddling diesel vehicles, and now General Motors is facing some of that heat.

A class-action lawsuit filed in federal court in Detroit accuses GM of using three “defeat devices” in its Duramax diesel engines to cheat on emissions tests. The suit was filed on behalf of 705,000 people who own or lease 2011-2016 Chevrolet Silverado and GMC Sierra heavy-duty pickup trucks. The suit does not include light-duty versions of the Silverado or Sierra, which don’t offer diesel engines, or diesel Chevy Colorado and GMC Canyon trucks, which use different engines that share the Duramax branding.

“These claims are baseless and and we will vigorously defend ourselves,” a GM spokesperson told Reuters, adding that the trucks in question comply with both federal Environmental Protection Agency emissions standards and California’s stricter standards. Supplier Bosch was also named as a defendant for having allegedly helped develop the “defeat devices,” but the company would not comment on the litigation.

According to the complaint, affected trucks produce two to five times the legal levels of nitrogen-oxide (NOx) emissions. It also alleges that modifying the trucks to comply with emissions standards could have an adverse affect on power and fuel efficiency.

The lawsuit was filed by multiple law firms, including Seattle-based Hagens Berman Sobol Shapiro, which was involved in settlements with Volkswagen on behalf of both owners and dealers over the German automaker’s use of illegal “defeat devices.” The firm previously filed a lawsuit against GM alleging emissions cheating in the first-generation Chevrolet Cruze Diesel. It has also filed suits against Mercedes-Benz and Fiat Chrysler Automobiles (FCA) over claims of emissions cheating.

Filing of the class action comes just days after the Justice Department filed a suit against FCA, accusing the automaker of using software to cheat on emissions tests. In January, the EPA accused FCA of installing illegally undisclosed software in 104,000 Ram 1500 pickup trucks and Jeep Grand Cherokee SUVs from model years 2014 to 2016 equipped with the 3.0-liter EcoDiesel V6. The automaker said it would update its software, and applied to certify its diesels for the 2017 model year just before the Justice Department suit was announced.