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The California Air Resources Board (CARB) has the responsibility of developing programs to reduce pollutants emitted from mobile sources in accordance with the Clean Air Act. A major challenge in California's air quality stems from heavy-duty diesel vehicles weighing over 14,000 pounds, as they contribute the most to on-road NOx and PM 2.5 emissions. Despite CARB's previous efforts over the span of 40 years to reduce these emissions, heavy-duty diesel vehicles remain a primary concern. To address this issue, CARB has introduced the Clean Truck Check. This regulation focuses on ensuring these vehicles are well-maintained and promptly repaired when necessary, promoting fairness among businesses operating them. The Clean Truck Check includes various components, such as roadside emissions monitoring, improved testing procedures utilizing on-board diagnostics data, emissions checks, data reporting requirements, and compliance verification measures. With its implementation, the regulation is projected to make a substantial impact by reducing statewide NOx emissions by over 81 tons per day and PM emissions by 0.7 tons per day by 2037. These reductions are expected to prevent over 7,500 premature deaths.

  • CARB is responsible for developing programs to reduce pollutants from mobile sources under the Clean Air Act.

  • Heavy-duty diesel vehicles over 14,000 pounds are significant contributors to air pollution in California.

  • CARB has made efforts to reduce emissions from these vehicles in the past with regulations and incentive programs.

  • Modern heavy-duty diesel vehicles have emissions control systems, but malfunctions can lead to increased emissions.

  • The Clean Truck Check aims to ensure proper maintenance and prompt repairs of heavy-duty vehicles in California.

  • It includes various measures like emissions monitoring, improved testing procedures, and compliance verification requirements.

  • The regulation is expected to significantly reduce NOx and PM emissions, leading to thousands of avoided premature deaths.​

If your vehicle is a 2010 model year or older, it might not meet the Truck and Bus regulation. This could be why there is a hold on your vehicle's registration. For more information, go to the TruckStop DMV page.

The hold on your registration could also be because CARB enforcement placed it, as they have the authority to do so for noncompliance with any CARB regulation. 

Starting in 2024, the registration hold may also be because your vehicle doesn't meet the requirements for the Clean Truck Check program.



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