Mack, Volvo expand DEF software updates

Mack Trucks and Volvo Trucks North America are phasing rollout of updated diesel exhaust fluid inducement software across their vehicle lineups.

The updates align with revised Environmental Protection Agency guidelines for selective catalytic reduction systems. Under the new EPA guidance, final inducement speed limits increase from 5 mph to 25 mph, and allowable repair windows expand from four hours to up to 160 hours—giving fleets significantly more time to service emissions issues before vehicle performance is severely restricted.

Daimler Truck North America, Cummins and PACCAR have also announced the rollout of DEF software patches. 

Both Mack and Volvo began factory installation of the software in May 2026 on select new models—including Mack Pioneer and Anthem trucks equipped with MP13 engines, and Volvo VNL and VNR models with D13 VGT and D13 TC engines. Both brands plan to offer remote updates for model year 2024 and newer vehicles by late summer.

The companies outlined matching release schedules for legacy vehicles:

• Second quarter 2027: Updates expand to cover all post-2014 model year vehicles.
• Late 2027: Updates become available through local dealerships for all eligible post-2010 models lacking over-the-air update capabilities.