Cummins is voluntarily recalling approximately 500,000 medium and heavy-duty trucks built between 2010 and 2015 — the largest voluntary truck emissions recall in U.S. history, according to the Environmental Protection Agency (EPA).
The problem stems from the durability of the selective catalytic reduction (SCR) system. The SCR system controls NOx emissions, and was designed to last for what is considered the full useful life of the vehicle — 185,000 miles (333,000 km) or ten years for medium-duty and 435,000 miles (783,000 km) or ten years for heavy-duty trucks.
The EPA and the California Air Resources Board (CARB) routinely check emissions from privately-owned vehicles in customer service. In the course of these tests it was determined that the SCR systems were deteriorating and then failing to control NOx emissions for the minimum time required by statute.
Cummins conducted its own tests and, when it confirmed the results of the government testing, it voluntarily initiated the recall.
An earlier recall involved about 232,000 Dodge Ram 2500 and 3500 pickup trucks, bringing the total number of affected vehicles to about 770,000.
Cummins will contact owners of the vehicles with instructions, as to how they plan to proceed. Owners can contact Cummins directly about which trucks are affected and when they can be taken in to be repaired.
During an earnings call this week, Cummins said it had set aside $181 million for the recall.