Clean Truck Check Guidance Documents Released

The California Air Resources Board (CARB) has released guidance documents on the Clean Truck Check program. 

The the Heavy-Duty Inspection and Maintenance (HD I/M) Program, known as Clean Truck Check, was approved by CARB in December 2021 to ensure heavy-duty vehicle emissions control systems operate properly throughout the life of the vehicle.  It requires non-gasoline (diesel, alternative fuel, and hybrid) trucks, buses, and other heavy-duty vehicles, such as California-registered motorhomes, with a gross vehicle weight rating (GVWR) over 14,000 pounds that operate in California to undergo emissions testing. Requirements include database registration, per vehicle compliance fees, and periodic testing.

It applies to most vehicles that operate in California, regardless of where they are registered, except for: 

  • Zero-emission trucks
  • Military tactical vehicles
  • Authorized emergency vehicles
  • Motorhomes registered outside of California
  • Vehicles operating under an experimental permit
  • Historical vehicles
  • Gasoline vehicles

The new guidance information is listed below or you can click here to view the website.  Email the Clean Truck Check Team at with any questions you may have about the program.

Implementation Guidance

2024 Periodic Testing

Database Reporting