Relief from DEF inducements coming for Kenworth and Peterbilt trucks
Heavy-duty truck maker PACCAR Inc announced software updates are available for Kenworth and Peterbilt trucks in alignment with recent U.S. Environmental Protection Agency’s (EPA) guidance on Diesel Exhaust Fluid (DEF) inducements.
On July 6, 2026, PACCCAR announced that emissions control software updates are available for vehicles equipped with PACCAR MX-11 and PACCAR MX-13 engines.
PACCAR said that the updates will support Kenworth and Peterbilt customers by:
- Having the final inducement speed limit increased from 5 mph to 25 mph
- Extending the timeline from 4 to 160 hours for component-related or fluid-quality issues before reaching final inducement speed limit
Trucks manufactured after July 20, 2026, will have the updates installed at the factory.
Trucks built after 2018 will have software updates installed at Kenworth or Peterbilt dealerships.
The software updates were released in response to EPA guidance issued in August 2025 meant to provide relief for truckers and farmers from DEF inducements often caused by low DEF levels or reduced Selective Catalytic Reduction (SCR) system performance.
“DEF inducements prompt drivers to correct the issue by refilling the DEF tank, repairing faulty sensors, or performing a system regeneration,” PACCAR said.
In June 2026, Daimler Truck North America LLC announced a similar software update to comply with the new EPA guidelines.