Cold Weather Diesel Reliability Act of 2025

Key Points

• Modern diesel engines have systems that automatically slow down or shut off the engine if the pollution control system breaks. In extreme cold, the fluid used to clean exhaust can freeze. This often tricks the engine's computer into thinking there is a major failure, causing the truck to lose power or stop entirely.
• This bill requires the EPA to let truck makers turn off these automatic shutdowns when the temperature is at or below 32 degrees Fahrenheit. The goal is to prevent drivers from being stranded in life-threatening, freezing conditions just because a sensor or fluid system isn't working correctly in the cold.
• The plan also creates a permanent, year-round exemption for vehicles used in the far north, such as parts of Alaska. These vehicles would not be required to have the automatic shutdown systems that are triggered by exhaust fluid issues, acknowledging that these systems are often impractical in those climates.
• Supporters argue that while pollution controls are important, they should not put lives at risk. In remote areas with no cell service or emergency help, a stalled engine can be a death sentence. This change ensures that engine shutdowns don't happen when a driver's survival depends on a running vehicle.
• Once the temperature rises above freezing, the engines must return to their normal operation. This ensures that the pollution-cutting technology still works as intended during most of the year, only pausing when the extreme weather makes the equipment unreliable.

Impact Analysis

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