California Air Resources Board

​Overview

The purpose of this guidance is to provide updated information on the expected start date of Clean Truck Check periodic compliance testing in 2024 to owners of motorhomes registered in California and owners of vehicles used exclusively in agricultural operations. These heavy-duty vehicles are subject to annual compliance testing rather than semiannual testing as required for all other vehicles subject to Clean Truck Check. Please refer to ”Guidance to Vehicle Owners on 2024 Periodic Testing Requirements for Vehicles Subject to Semiannual Testing” for compliance deadlines for these other vehicles.

This guidance also augments previous guidance released in late June 2023 on CARB’s plans to implement a three-month open reporting season projected to run from October 1, 2023, to December 31, 2023. To access the previous guidance, please see: June 2023 Guidance to Vehicle Owners on Upcoming Requirements | California Air Resources Board.

Key highlights from this guidance are:

• CARB staff projects that periodic testing requirements will start for California registered motorhomes and agricultural vehicles[1] in 2024. Tables I and II present projected 2024 annual compliance deadlines.
  •  A passing compliance test will be required to be submitted to CARB within the 90 days before a vehicle’s compliance deadline.

Vehicles Affected by this Guidance

Nearly all diesel and alternative fuel heavy-duty trucks, buses, and other vehicles with a gross vehicle weight rating over 14,000 pounds that operate in California are subject to the Clean Truck Check. Most vehicles subject to this program fall under semiannual testing requirements. However, California registered motorhomes and heavy-duty vehicles used exclusively in agricultural operations are subject to annual testing requirements. This guidance document lays out projected 2024 compliance testing deadlines for vehicles subject to annual testing. See Tables I and II for projected 2024 compliance deadlines. For information on vehicles that are exempt from Clean Truck Check, please refer to the Fact Sheet: Heavy-Duty Inspection and Maintenance Program: Background and Requirements.

2024 Periodic Testing Requirements

To be deemed compliant with Clean Truck Check, a passing compliance test from an applicable vehicle must be submitted to CARB within the 90 days before a vehicle’s compliance deadline. For example, if a vehicle’s periodic compliance deadline in 2024 is November 30, a passing compliance test would need to be submitted to CARB’s Clean Truck Check database system between September 1, 2024, and November 30, 2024. The vehicle’s 2024 annual compliance fee also would be due by the compliance deadline. The Clean Truck Check database system will provide vehicle owners and fleet managers access to the schedule of their vehicles’ upcoming periodic compliance testing deadlines and compliance fee payments.

A. California Registered Motorhomes and California Registered Agricultural Vehicles

In general, California registered motorhomes and California registered agricultural vehicles will be required to test annually on a schedule that aligns with each vehicle’s DMV registration expiration day. However, for 2024 only, compliance deadlines for all vehicles will be extended to the second half of the year to provide vehicle owners with added time to determine which compliance testing option best meets their needs. To identify when your vehicle’s annual 2024 periodic compliance test will be required, refer to Table I below.

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

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, 2024.
• A vehicle with a DMV registration expiration on July 31, 2024, also will have a 2024 compliance deadline on July 31, 2024.
• A vehicle with a DMV registration expiration on October 31, 2024, will have a 2024 compliance deadline on October 31, 2024.

Starting in 2025, all California registered motorhomes and California registered agricultural vehicles will have annual compliance deadlines that align with their actual DMV registration expiration dates. 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. The vehicle’s annual compliance fee also will be due by this same deadline. Figure I below illustrates the compliance deadline and 90-day submission window in 2024 and 2025 for a California registered motorhome with an October 31 DMV registration expiration.

Figure I: Projected Periodic Testing Dates for a California Registered Motorhome with an October 31 DMV Registration Expiration Date

B. Non-California Registered Agricultural Vehicles

Table II presents the compliance deadlines for non-California registered agricultural vehicles. In general, compliance deadlines for vehicles not registered in California are based on the last number of the vehicle’s vehicle identification number (VIN). For further details, refer to the Fact Sheet: Heavy-Duty Inspection and Maintenance Regulation: Periodic Testing Requirements. However, as mentioned above, 2024 compliance deadlines will be extended to the second half of the calendar year to allow owners added time to determine which compliance testing option best meets their needs. These vehicles will have 2024 compliance deadlines in the months of July through December. To identify when your vehicle’s annual 2024 periodic compliance test will be required, refer to Table II below. Table II below also shows the compliance month for 2025 and beyond based on vehicles’ VINs.

Table II: 2024 Projected Periodic Compliance Testing Deadlines for Non-California Registered Agricultural Vehicles

In the VIN-based compliance schedule, a vehicle’s periodic compliance testing deadline falls on last day of the compliance deadline month. Examples of compliance deadlines using Table II include:

• A vehicle with “7” as the last number in its VIN would have a compliance deadline on November 30 in 2024.
• A vehicle with “1” as the last number in its VIN would also will have a 2024 compliance deadline on November 30 in 2024.
• A vehicle with “0” as the last number in its VIN would have a compliance deadline on October 31, 2024.

Figure II below illustrates the compliance deadline and 90-day submission window in 2024 and 2025 for a vehicle with a “0” as the last number in its VIN. In 2024, this vehicle will be subject to an annual compliance deadline on October 31 based on Table II. Starting in 2025, the ongoing annual compliance deadline for this vehicle also will be October 31.
Figure II: Projected Periodic Testing Dates for a Vehicle with a “0” as Last Number in its VIN

[1] Agricultural vehicles refer to vehicles owned or operated by a farming business that are used exclusively in agricultural operations to transport agricultural products to the first point of processing.

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