The US Environmental Protection Agency just announced the largest voluntary recall of medium- and heavy-duty trucks to date. Diesel engine manufacturer Cummins will recall some 500,000 trucks from the 2010 to 2015 model years due to faulty emissions control systems.
According to an EPA release, the defective emissions control systems cause "excess emissions of nitrogen oxides (NOx)." But unlike the infamous Volkswagen Group diesel scandal, in which defeat devices were used to cheat emissions regulations, the Cummins engines are simply fitted with defective parts.
"The trucks being recalled are equipped with selective catalytic reduction (SCR) systems designed to control NOx emissions," the EPA said in an official statement. "The SCR catalysts that will be replaced through the recall were found to be less durable than is required, degrading within a few years instead of controlling NOx pollution for the regulatory full useful life of the vehicle."
A Cummins spokesperson tells Roadshow the recall will be rolled out in two phases. Heavy-duty engine customers will receive notifications in August 2018, with the medium-duty engine recall to follow in March 2019. The affected vehicles range anywhere from large pickups to RVs to semi trucks. A similar, earlier recall involved roughly 232,000 Ram 2500 and 3500 pickups.
Both the EPA and the California Air Resources Board (CARB) discovered the emissions problems during independent testing. Cummins verified the organizations' findings in followup testing and agreed to recall all affected engines.
"This is the way it's supposed to work," spokesperson Bill Wehrum said in the EPA statement. "Our followup testing seeks to make sure that pollution controls work throughout an engine's useful life. And, if they don't, then companies step up to set things right."