— A GM Duramax diesel lawsuit alleges 2011-2016 GMC Sierra 2500 and 3500 and Chevy Silverado 2500 and 3500 trucks are equipped with illegal emissions devices that cause real-world nitrogen oxide levels to be two to five times higher than legal limits.
Nitrogen oxides are a combination of several compounds made of nitrogen and oxygen atoms and formed in the engine cylinders during the combustion process.
The pollution aspect arises from nitrogen dioxide and the particulate matter that react with sunlight to form ozone.
Nitrogen oxides have been linked to multiple health problems related to respiratory and cardiovascular systems.
The original lawsuit was filed in May 2017, but this amended complaint adds details about the alleged collusion between GM and parts supplier Bosch.
According to the plaintiffs, their testing indicates that GM and Bosch programmed the software to detect possible emission testing procedures and to comply with emissions requirements in a lab setting, but to turn off the emissions controls when a testing environment is not detected.
The plaintiffs allege GM marketed the trucks and their Duramax engines would turn “heavy diesel fuel into a fine mist,” delivering “low emissions” that were a “whopping reduction” compared to the prior models. GM also claimed its engineers had accomplished a “remarkable reduction of diesel emissions.”
Any promised power, fuel economy and efficiency can allegedly only be obtained by turning off or turning down emissions controls when the software in these trucks senses they are not in an emissions testing environment.
The lawsuit alleges the trucks are equipped with three emissions defeat devices. The lawsuit describes a defeat device as an "auxiliary emissions control device that reduces the effectiveness of the emission control system under conditions which may reasonably be expected to be encountered in normal vehicle operation and use."
One alleged device reduces the emissions system when temperatures are above the emissions certification test range of 86°F. The second alleged device is used to turn down emissions controls when temperatures go below the emissions certification temp of 68°F, and attorneys say testing shows that anything below 68°F will cause emissions to be two times higher than legal limits.
The lawsuit alleges a third defeat device reduces the level of emissions controls after 200-500 seconds of steady speed operation in all temperatures, causing emissions to increase on average of a factor of 4.5.
GM allegedly reversed the traditional order of the exhaust treatment components and put the selective catalytic reduction (SCR) in front of the diesel particulate filter (DPF), allowing the automaker to market higher power and fuel efficiency from its engines while still passing the cold-start emissions certification tests.
However, reversing things also allegedly increased the need for the system to burn off collected soot at high temperatures and reversing the very advantage gained.
Working with Bosch, GM allegedly installed the devices to gain the advantage of hot exhaust going into the SCR system needed to pass cold-start tests, all while avoiding the fuel- and power-robbing active regeneration procedure the DPF filter requires when the SCR treatment comes first.
According to the lawsuit, General Motors worked in concert with parts supplier Bosch, a company already in trouble for supplying emissions parts for Volkswagen diesel vehicles.
Bosch allegedly developed, manufactured and tested the electronic diesel controls (EDC) that allowed GM to use the defeat devices. The lawsuit references the Bosch "EDC17" allegedly used for the “defeat devices” as it enables the software to detect conditions when emissions controls can be reduced.
The plaintiffs claim nearly all the vehicles found or alleged to have been manipulating emissions in the U.S. (Mercedes, FCA, Volkswagen, Audi, Porsche, Chevy Cruze) use a Bosch EDC17 device.
According to the plaintiffs, they paid about $9.000 for their Durmax diesel Silverado 2500 and 3500 and Sierra 2500 and 3500 trucks over comparable gasoline-powered Silverados or Sierras.
The lawsuit was filed in the U.S. District Court for the Eastern District of Michigan - In RE: Duramax Diesel Litigation.
The plaintiffs are represented by Hagens Berman Sobol Shapiro LLP, The Miller Law Firm PC, Seeger Weiss LLP, Hilliard Muñoz Gonzales L.L.P., Carella, Byrne, Cecchi, Olstein, Brody & Agnello, P.C., and Lieff Cabraser Heimann & Bernstein.
CarComplaints.com has owner-reported complaints about the GM trucks named in the emissions lawsuit: