CARB plans to implement a three-month open reporting season projected to run from October 1 to December 31, 2023. By December 31, 2023, vehicle owners need to complete reporting of their vehicles in the Clean Truck Check database and pay a $30 per vehicle 2023 annual compliance fee. CARB estimates that periodic testing requirements will start in July 2024. This means that a passing compliance test would be required to be submitted to CARB for vehicles with compliance deadlines on or after July 1, 2024.
*NST: Notice to submit to testing
Clean Truck Check Regulation Timeline
Ways to prepare for upcoming Clean Truck Check Requirements
Watch the upcoming Reporting Webinars
- Verify which vehicles in your fleet are subject to the Clean Truck Check program.
- Prepare to report affected vehicles and pay the annual $30 compliance fee to CARB by December 31, 2023.
- Prepare for compliance testing.
- Subscribe to email notifications and select Clean Truck Check (Heavy Duty Vehicle Inspection and Maintenance) to receive emails about program updates.
Live Zoom and in-person training opportunities available. For upcoming dates and times visit TruckStop Training and Events.
Clean Truck Check (HD I/M) Regulation Timeline.
Clean Truck Check Applicability and Exemptions
Clean Truck Check 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. Clean Truck Check applies to most vehicles that operate in California, regardless of where they are registered. The purpose of the program is to ensure all emissions related equipment is functioning properly for the life of the vehicle.
The Clean Truck Check Program does not apply to:
- Zero-emission trucks
- Military tactical vehicles
- Authorized emergency vehicles
- Motorhomes registered outside of California
- Vehicles operating under an experimental permit
- Historical vehicles
- Gasoline vehicles
Compliance Demonstration Requirements
Vehicle owners must demonstrate that affected vehicles comply with Clean Truck Check requirements to legally operate in California. DMV may block registration on California-based vehicles that have not demonstrated compliance.
At full implementation, an affected vehicle will be deemed compliant when:
- There are no outstanding enforcement actions on the vehicle.
- There are no outstanding emissions or on-board diagnostics (OBD) related recalls on the vehicle.
- The owner has paid an annual compliance fee to CARB.
- The owner has reported owner and vehicle information to CARB.
- The owner has demonstrated compliance with the periodic vehicle emission testing requirements by submitting a passing compliance test to CARB.
Notice to Submit to Testing
As of January 2023, Roadside Emissions Monitoring Devices (REMD) are being used throughout California to screen for potential high emitting vehicles. Owners of vehicles identified as potential high emitters are issued a Notice to Submit to Testing (NST) letter and have 30 days to submit a passing emissions test to CARB. Failure to submit a passing test may result in an enforcement violation. Enforcement staff are also conducting roadside inspections now to verify compliance.
If you receive a NST letter, please visit If You Receive A Notice to Submit to Testing (NST) Letter.
Reporting Requirements
Vehicle reporting is proposed to open October 1, 2023, and must be completed by December 31, 2023, and annually thereafter. During this time, vehicle owners will be required to use the Clean Truck Check database system to report vehicle and owner information and submit an annual $30 per vehicle compliance fee.
To successfully complete the process, owners will need to provide essential company/fleet information, including the entity name, company contact details, and U.S. Department of Transportation (U.S. DOT) number. Owners will also be required to indicate ownership for each vehicle within the fleet by providing the corresponding Vehicle Identification Number (VIN). The $30 per vehicle compliance fee would be payable directly through the database system using traditional payment methods such as major credit cards, debit cards, and electronic fund transfers.
Be prepared with the required information to make reporting easy once the Clean Truck Check database becomes available.
CARB staff will offer training webinars and instruction videos to educate vehicle owners on how to use the database system and what information must be reported into the system.
Periodic Testing Requirements
Periodic Smoke Inspection Program (PSIP) testing is required for in-state fleets until full implementation of the Clean Truck Check. For information on PSIP visit Clean Truck Check (HD I/M) & Periodic Smoke Inspection Programs. At full implementation of Clean Truck Check, the periodic testing requirements will be:
2013+ Model Year (MY) engines: On-Board Diagnostics (OBD) equipped vehicles
- OBD test submission: twice per year
- OBD test submission increases to four times per year after 3 years of two times per year testing
- CA Motorhomes: once per year
- On-Road Agricultural (AG) Vehicles: once per year
Pre-2013 MY engines: Non-OBD equipped vehicles
- Opacity test submission (for diesel vehicles) and visual/functional inspection (all fuel types): twice per year
- CA Motorhomes: once per year
- On-Road Agricultural (AG) Vehicles: once per year
Submit passing test within 90 days before compliance test deadlines
- CA registered vehicles: based on DMV registration date*
- Out-of-state registered vehicles, California exempt-plated vehicles (state and local public agency vehicles), and federal government vehicles: based on last number of VIN**
* Example of periodic compliance dates for a CA registered vehicle: If the vehicle’s DMV registration date is March 31, then the vehicle’s periodic submission deadlines would be March 31 and September 30 (6 months later) for a given year.
**Example of periodic testing compliance dates for an out-of-state registered vehicle, California exempt-plated vehicle, or a federal government vehicle:
VIN ending in “5” has compliance deadline of March 31 and a second compliance deadline on September 30 (6 months later). Compliance deadlines are based on the following chart:
Emissions Testing Methods
The testing method is dependent on whether the vehicle has standardized OBD or not.
OBD-equipped vehicles include the following vehicles:
Vehicles equipped with a 2013 MY and newer diesel or diesel hybrid engine. Vehicles equipped with a 2018 MY or newer alternative fuel or alternative fuel hybrid engine.
Non-OBD vehicles are equipped with 2012 or older engines
Below are the methods for OBD and non-OBD vehicles:
OBD vehicles must have an OBD test performed and submitted by either of the following methods:
- A telematics service provider device that meets CARB’s data format submission requirements
- Hand-held scan tools and plug-in dongles that meet CARB’s data submission requirements
Testing must be performed by a credentialed tester with an approved OBD device. CARB maintains a list of approved OBD devices that is updated as more devices become available.
Non-OBD
- Diesel vehicles must pass the SAE J-1667 opacity test
- Performed with opacity testing equipment that meet the SAE J1667 specifications
- See Smoke Meter Manufacturers for applicable smoke meters
- Alternative fuel vehicles are exempt from the opacity test.
- All non-OBD vehicles must also pass a visual/functional inspection of the vehicle’s emissions control components to check for tampering.
- Testing must be performed by a credentialed tester.
Credentialed Clean Truck Check Tester
To ensure consistency, the Clean Truck Check program requires that all non-telematics emissions testing and reporting is performed by credentialed testers. Any individual from any state, Canada, or Mexico is eligible to complete CARB training to become a credentialed tester. Credentialed testers will need to renew their credentials every two years. The free, online credentialed tester training course is available now.
The online training includes the following training modules and an exam:
- Regulatory requirements
- Smoke opacity compliance testing
- OBD compliance testing
- Vehicle emissions control inspections
Freight Contractor, Broker, and Applicable Freight Facility Requirements
- Applicable freight facilities (Seaport Facilities and Intermodal Railyards) must check that only compliant vehicles enter/operate on their properties or maintain records of non-compliant vehicles entering or operating on their properties.
- Freight contractors and brokers must check for compliance documents and retain records.
Additional Information
More detailed information can be found on the Clean Truck Check program page.
Fact Sheets & FAQs provide further details on program requirements such as vehicle applicability, compliance testing requirements, and allowable testing equipment. For a complete list of printable TruckStop resources, visit Printable Materials.
To receive notification when the Clean Truck Check database system is available, reporting training, and to receive other important Clean Truck Check updates, please subscribe.
If you have questions regarding Clean Truck Check, please email Clean Truck Check staff at hdim@arb.ca.gov.