A Detroit DD15 Gen 5 engine file photo. Daimler is updating its vehicles with the engine due to updated diesel exhaust fluid guidance.This story was originally published on Trucking Dive. To receive daily news and insights, subscribe to our free daily Trucking Dive newsletter.Dive Brief:Daimler Truck North America is rolling out updated engine software across roughly 330,000 trucks after the U.S. Environmental Protection Agency revised its guidance related to diesel exhaust fluid inducement systems, the company announced in a June 18 press release.The update will apply to Detroit DD15 and DD13 engines in model year 2021-2025 vehicles and will be implemented over the course of 2026.Daimler's new Freightliner and Western Star vehicles are already shipping with the updated software.Dive Insight:The EPA scaled back certain DEF-related requirements introduced under previous emissions regulations in August, and in March, the agency issued another update to its guidance, clarifying that manufacturers can adopt alternative motoring technologies including software-based solutions.AdvertisementAdvertisementHistorically, failures within DEF components could trigger inducement protocols that progressively limited truck performance until repairs were completed. Under the previous requirements, trucks were restricted to 5 miles-per-hour speed limits when an issue arose that required maintenance; however, the revision has updated that level to 25 miles per hour. Operators also have more flexibility to complete repairs with additional time before final inducement occurs for component-related issues.Daimler said it has notified its dealer network of these updates for consistency and support for implementation across its footprint. The release noted customer concerns about downtime and repair costs associated with frequently faulty DEF systems."For too long, small businesses like farmers, truckers, and construction workers have borne the cost of unreliable DEF systems through expensive repairs and needless downtime," Kelly Loeffler, administrator of the U.S. Small Business Administration, said in the press release. "The SBA welcomes Daimler Truck North America's decision to equip vehicles with updated DEF inducement software, a common-sense step that gives operators greater reliability while reducing costs."Recommended ReadingEPA axes diesel exhaust fluid sensor requirements',