Agency to Independently Evaluate Ongoing System Failures
The head of the Environmental Protection Agency, Lee Zeldin, is asking major diesel engine manufacturers to share critical information about problems with diesel exhaust fluid (DEF) systems. This will help fix equipment issues for truckers and farmers.
EPA wants information from the 14 biggest companies that make more than 80% of DEF system products used in trucks and other equipment.
Zeldin said, “EPA knows this is a big problem. We have already instructed companies to update their DEF systems. We want to help farmers and truckers avoid delays and problems.”
EPA will use the information it gets to study DEF system problems and decide what to do next in 2026.
Zeldin added that during his visits to all 50 states, many truckers and farmers told him about DEF problems and asked for a solution.
EPA is looking for potential issues with DEF system components as it plans new rules.
EPA said that DEF system failures cause trucks and equipment to suddenly slow down or stop, which is unsafe and hurts work. The agency told companies to update their software to prevent these sudden shutdowns and give people more time to fix problems. EPA also said that DEF systems need to be designed and manufactured with the best materials.
Information the EPA is asking from Engine Makers
Under the Clean Air Act, the EPA can require companies to provide information to determine whether their emission control systems are functioning properly. EPA can also check if companies are fixing problems.
From February 2, engine makers have 30 days to give EPA data about their 2016, 2019, and 2023 emission products, including:
- Failure rates
- Repair information
- Warranty claims
EPA will use this information to determine whether current DEF problems are linked to specific years or models. Companies that miss the deadline may be fined.
EPA also told companies that Americans have the right to fix their farm or other equipment under the Clean Air Act. This lets farmers repair DEF systems themselves, saving time and money.
In August, the EPA told truck companies to update truck software so engines would not shut down when DEF tanks run empty. Most trucks built since 2010 have these systems to meet new pollution rules.
EPA has been talking with companies to check their progress toward making better software, as EPA requested.
EPA said that starting with 2027 models, all new diesel trucks must be built so they do not suddenly lose significant power if they run out of DEF.
Under the new rules, heavy-duty trucks now get a warning light for 650 miles or 10 hours after a problem is found. After that, the engine will slow down a little, but the truck can still run normally for up to 4,200 miles or two weeks. Only after about four weeks does the speed drop to 25 mph until repairs are done. For equipment not used on roads, nothing happens for the first 36 hours; after that, the engine loses a little power.
EPA said it continues to push companies to implement these changes as soon as possible.
