Cummins Inc. has begun updating certain engine calibrations to give operators more time to complete needed repairs and help minimize unnecessary downtime related to diesel exhaust fluid (DEF) inducements. The updates continue to support emissions compliance and the performance of selective catalytic reduction technology, with a focus on the people and businesses that depend on this equipment to do their jobs every day.

Following updated guidance from the U.S. Environmental Protection Agency (EPA), the revised calibrations increase the amount of time before certain DEF-related inducements occur and increase final inducement speeds in certain circumstances. Emissions compliance remains mandatory.

“We appreciate EPA’s engagement with industry stakeholders and view the revised guidance as an important step toward addressing customer concerns in a practical, compliance-focused way,” said Brett Merritt, vice president and president, Engine Business. “Cummins has acted to support reliable implementation of these updates, help customers and operators reduce unnecessary downtime, and continue to meet emissions requirements.”

For heavy-duty truck and tractor engines, the updates extend the time to initial and subsequent derate events for certain tampering and DEF quality conditions and increase final derate speed from 5 mph to 25 mph. For eligible motorcoach applications, the updates provide additional flexibility, including more time before initial inducement, removal of the secondary derate step in certain conditions and an increase in final derate speed from 5 mph to 50 mph.

DEF remains required for the emissions system to operate properly, and DEF-level inducement steps based on remaining tank level remain in place. These updates are intended to provide additional operational flexibility while maintaining emissions system requirements.

Cummins has already begun offering revised calibrations for over 1.5 million engines in medium and heavy-duty trucks, including certain truck applications dating back to model year 2017 and certain motorcoach applications dating back to model year 2018, with timing varying by engine platform and model year.

Customers may contact their local Cummins distributor or dealer to schedule available updates.

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