Check Out Our List of Frequently Asked Questions Regarding California’s New Clean Truck Check Program.

We understand that new programs can be complicated. Here are some helpful answers to get your fleet prepared for the Clean Truck Check.

Question What is the Clean Truck Check Program?
AnswerIn December 2021, the California Air Resources Board (CARB) approved the Heavy-Duty Inspection and Maintenance (HD I/M) Program, now known as Clean Truck Check, in an ongoing effort to meet air quality standards by ensuring heavy-duty vehicle emissions control systems operate properly throughout the life of the vehicle. The program requirements include reporting in the Clean Truck Check database (, paying annual per vehicle compliance fee ($30), and submitting periodic testing results.
Question What Vehicles Are Affected By The Clean Truck Check Program?
AnswerNearly all diesel and alternative-fuel (CNG, LNG, Hydrogen, Hybrid-Diesel) heavy-duty trucks, buses, and other vehicles with a gross vehicle weight rating over 14,000 pounds that operate in California are subject to semiannual testing. Affected vehicles include hybrid trucks and buses, commercial vehicles, privately-owned vehicles, government vehicles, and vehicles registered outside of California. (State/Country)

California registered motorhomes and heavy-duty vehicles used exclusively in agricultural operations (California registered and non-California registered) are required to undergo periodic compliance testing annually (Once per year), rather than semiannually (twice per year).

Question When Does the Clean Truck Check Compliance Requirement Begin?
AnswerPeriodic vehicle testing requirements would become effective January 1st, 2024. This requirement means that a passing compliance test would need to be submitted to CARB within 90 days prior to a vehicle’s compliance deadline. For example, if a vehicle has a compliance deadline on July 1, 2024, a passing compliance test would need to be submitted between April 2, 2024, and July 1, 2024.

Based on the projected timing of the periodic testing requirements, most vehicles would be required to undergo one periodic compliance test in 2024. Starting in calendar year 2025, most vehicles would then be subject to the standard twice per year periodic testing requirements.

Question How Do I Determine My Compliance Deadline?

Compliance deadlines for California registered vehicles are based on their DMV registration expiration dates. In general, a vehicle required to test semiannually will have two compliance deadlines each year:

1) Date of your vehicle’s registration expiration

2) Six months after the DMV registration expiration date. To identify when your vehicle’s one 2024 periodic compliance test will be required, refer to Table I below.

Table I: 2024 Projected Periodic Compliance Testing Deadlines for California Registered Vehicles

DMV Registration ExpirationMonth Jan Feb Mar April May June July Aug Sept Oct Nov Dec
2024 Compliance Deadline Month July Aug Sept Oct Nov Dec July Aug Sept Oct Nov Dec

For a California registered vehicle, its compliance deadline is based on the numerical day of its DMV expiration. Examples of compliance deadlines using Table I include:

  • A vehicle with a DMV registration expiration on January 31, 2024, will have a 2024 compliance deadline on July 31.
  • A vehicle with a DMV registration expiration on July 31, 2024, also will have a 2024 compliance deadline on July 31.
  • A vehicle with a DMV registration expiration on May 31, 2024, will have a 2024 compliance deadline on November 30 (the last day of November).

Starting in 2025, California registered vehicles will be subject to both semiannual compliance deadlines. In all cases, a passing compliance test must be submitted to CARB within the 90 days before a compliance deadline. This period is referred to as the 90-day submission window. Figure I below illustrates the compliance deadlines and
90-day submission windows in 2024 and 2025 for a vehicle with a May 31st DMV registration expiration.

Question What is needed to comply with the Clean Truck Check Program?
AnswerCompliance Requirements for the Clean Truck Check are as follows:

Register your fleet with the Clean Truck Check Reporting Database ( and paying the $30.00 reporting fee per vehicle.

The testing requirements depend on whether your vehicle/engine is equipped with OBD or not.

OBD equipped vehicles are required to undergo a scan of the engines’ OBD data using a CARB-validated OBD test device.

Non-OBD vehicles, i.e., those that don’t meet the engine model year requirements above, are required to undergo a smoke opacity test and a visual inspection of the vehicle’s emissions control equipment, referred to in the Clean Truck Check program as the Vehicle Emissions Control Equipment Inspection. The smoke opacity test is the same SAE J1667 snap acceleration smoke inspection used to comply with CARB’s Periodic Smoke Inspection Program (PSIP).

Question Who can perform the Compliance Testing for the Clean Truck Check Program?
AnswerOnly a credentialed tester who is authorized to submit test results to California Air Resources Board (CARB) in accordance with the requirements of the Clean Truck Check (HD I/M) regulation can perform compliance testing and visual inspections on Non-OBD vehicles.

EERS has several credentialed testers on-site to perform Celan Truck Check for your fleet.  Contact us to schedule your Clean Truck Check today!.