Owners Of Duramax-Engine Trucks Accuse GM Of Using Emissions-Cheating Devices

Add General Motors to the growing list of carmakers accused of using so-called “defeat devices” to skirt federal emissions standards. Owners of GM trucks with Duramax diesel engines say the car company has been using secretly installed software to cheat on these tests — and boost sales — for more than five years.

The lawsuit [PDF], filed in district court in Michigan, claims that General Motors installed multiple defeat devices in more than 705,000 model year 2011 to 2016 Silverado and GMC Sierra Duramax diesel trucks in order to increase sales.

According to the 190-page complaint, GM used three distinct defeat devices — similar to those found in VW vehicles — to “de-rate” or turn down the emissions controls of the subject vehicles when they were not undergoing testing.

“GM claimed its engineers had accomplished a ‘remarkable reduction of diesel emissions,’” the lawsuit states, noting the carmaker’s promises that the Duramax engines could turn “heavy diesel fuel into a fine mist” and that the trucks delivered “low emissions, that were a ‘whooping reduction’ from the prior model.”

In reality, the lawsuit claims that instead of creating a system that would properly filter out emissions and pass inspection, GM installed defeat devices that involved reversing the traditional order of the exhaust treatment components to market the trucks as high power and efficient, while still passing federal emissions tests.

“This made GM’s trucks more appealing and competitive in the marketplace, driving up sales and profits,” the suit states.

However, by using the devices, the suit claims, GM’s trucks increased the amount of nitrogen oxide entering the atmosphere by up to five times the legal limit and decreased fuel and power during regular driving. In fact, the owners claim that the emissions spewed by the trucks polluted at levels well beyond legal limits and many times higher than their gasoline counterparts.

“GM turned a blind eye to the drastic increase in deadly NOx emissions its scheme caused–all to drive up its sales and profits,” Steve Berman, managing partner for Hagens Berman, the company representing GM owners, said in a statement.

The lawsuit, which make several references to Volkswagen’s defeat devices, also names tech provider Bosch as a co-defendant, claiming that GM did not act alone in the alleged deception.

“Bosch was an active and knowing participant in the scheme to evade U.S. emissions requirements,” the lawsuit claims, noting that Bosch developed, manufactured, and tested the diesel control that allowed GM to implement the defeat devices.

In a statement about the lawsuit, GM calls the allegations “baseless” and says it plans to defend itself in court.

“The Duramax Diesel Chevrolet Silverado and GMC Sierra comply with all U.S. EPA and CARB emissions regulations,” reads the statement.

The lawsuit against GM is just the latest since VW was first revealed to have used defeat devices in more than 11 million vehicles across the world in Sept. 2015. The carmaker has since entered into a number of agreements to pay billions of dollars in fines and refunds to customers, while also fixing the affected cars.

Just this week, the Justice Department and EPA filed a lawsuit against Fiat Chrysler, accusing the carmaker of using similar software to skirt emission standards in 104,000 vehicles.