Heavy Duty Trucking Logo
MenuMENU
SearchSEARCH

California Postpones Periodic Smog Test Check for Trucks

The California Air Resources Board has delayed the first periodic testing deadline for the Clean Truck Check Program to Jan. 1, 2025. But registration and fee requirements remain in place.

March 15, 2024
California Postpones Periodic Smog Test Check for Trucks

California has deployed emissions monitoring devices to monitor the exhaust of heavy-duty vehicles as they pass and flag potential violators of emissions regulations.

Photo: CARB

3 min to read


The California Air Resources Board has delayed the first periodic testing deadline for the Clean Truck Check Program to Jan. 1, 2025.

However, this does not delay requirements to register and pay fees for 2023. The rollout of DMV registration holds for non-compliance is beginning to ramp up, notes the California Trucking Association.

Ad Loading...

Fleets must also still plan to pay fees for 2024, which will be due in the later half of this year.

Late last year, CARB extended the Clean Truck Check reporting deadline to the end of January 2024.

About Clean Truck Check

Clean Truck Check, previously called the Heavy-Duty Inspection and Maintenance Program, is the commercial truck version of the state’s smog check for light-duty vehicles. It covers nearly all non-gasoline vehicles with a gross vehicle weight rating over 14,000 pounds operating in the state.

As HDT reported previously, the program is being implemented in three phases.

The first phase started Jan. 1, 2023, with the deployment of Remote Emissions Monitoring Devices. These monitor the exhaust emissions of passing heavy-duty vehicles and flag potential high emitters. Vehicles flagged must undergo an additional emissions test to verify their emissions-control equipment is functioning properly.

Ad Loading...

Phase 2 started Oct. 1 and requires vehicle owners to enter their vehicles in CARB’s Clean Truck Check database. There is an initial annual compliance fee of $30 per vehicle. That deadline originally was Dec. 31 and was extended to Jan. 31, but it is now in effect. All trucks driving in California need proof of compliance to continue operating.

Phase 3 of Clean Truck Check is what’s being delayed in this most recent postponement. It will require heavy-duty vehicle owners to conduct periodic emissions testing.

CARB's Periodic Truck Emissions Testing

Vehicles subject to semi-annual testing under the Clean Truck Check regulations will be required to submit periodic testing every six months.

California-registered vehicles’ compliance deadline will be the vehicles’ DMV registration expiration date. Vehicles registered outside of California have compliance deadlines based on their last VIN digit.

All trucks driving in California need proof of compliance that they've registered in the Clean Truck Program and paid the initial compiance fee to continue operating.

Source: CARB

Periodic testing requirements are effective Oct. 1, 2024. For example, a vehicle with a compliance deadline of Feb. 1, 2025, may submit a passing emissions test as early as November 3, 2024, according to CARB. Tests may be submitted no more than 90 days prior to the vehicle’s compliance deadlines.

Ad Loading...

Compliance testing must be performed by a CARB credentialed tester who has completed CARB’s free online Tester Training Course and scored at least 80% on the accompanying exam. The certification must be renewed every two years.

If you only operate for short periods of time in California, CARB offers a five consecutive day pass for each vehicle, once per calendar year. The 5-day pass must be submitted 7 business days before entering California.

For more information, see CARB’s guidance on how to comply with Clean Truck Check for vehicle owners subject to semi-annual testing.

More Maintenance

SponsoredFebruary 1, 2026

Reducing Fleet Downtime with Advanced Diagnostics

This white paper examines how advanced commercial vehicle diagnostics can significantly reduce fleet downtime as heavy duty vehicles become more complex. It shows how Autel’s CV diagnostic tools enable in-house troubleshooting, preventive maintenance, and faster repairs, helping fleets cut emissions-related downtime, reduce dealer dependence, and improve overall vehicle uptime and operating costs.

Read More →
SponsoredFebruary 1, 2026

Stop Watching Footage, Start Driving Results

6 intelligent dashcam tactics to improve safety and boost ROI

Read More →
Brake telematics in heavy trucks.
Maintenanceby Jack RobertsJanuary 30, 2026

Why Are Brake Telematics So Tough for Class 8 Trucks?

Brakes are the final frontier for telematics on Class 8 trucks. But Hendrickson is close to a breakthrough that could change the game in getting real-time brake system information back to fleets.

Read More →
Ad Loading...
Warehouse aisle with pallet racking filled with boxed inventory at a distribution center.
Maintenanceby News/Media ReleaseJanuary 28, 2026

Phillips Opens High-Tech Distribution Center for Faster Parts Delivery

Phillips Industries’ new Cincinnati-area distribution center is now shipping aftermarket trucking parts nationwide, aiming to speed up delivery times for customers.

Read More →
Cummins MFlex4 heavy-duty brake pad.
MaintenanceJanuary 20, 2026

Cummins Launches MFlex4 Air Disc Brake Pad for Heavy Duty Aftermarket

Cummins used Heavy Duty Aftermarket Week (HDAW) to introduce a new brake pad platform aimed squarely at one of the aftermarket’s biggest pain points: Complexity.

Read More →
SponsoredJanuary 19, 2026

3 New Ways Fleet Software Pays: ROI opportunities for modern fleet managers

Safety, uptime, and insurance costs directly impact profitability. This eBook looks at how fleet software is evolving to deliver real ROI through proactive maintenance, AI-powered video telematics, and real-time driver coaching. Learn how fleets are reducing crashes, defending claims, and using integrated data to make smarter operational decisions.

Read More →
Ad Loading...
SponsoredJanuary 19, 2026

Basic Tracking vs Next Generation Fleet Technology

Fleet software is getting more sophisticated and effective than ever, tying big data models together to transform maintenance, safety, and the value of your existing tech stack. Fleet technology upgrades are undoubtedly an investment, but updated technology can offer a much higher return. Read how upgrading your fleet technology can increase the return on your investment.

Read More →
MaintenanceJanuary 16, 2026

What is AI Doing for Pilot's Fleet Maintenance Program? [Video]

Artificial intelligence gets plenty of attention at tech shows like CES — but what does it look like in a real trucking maintenance shop? Watch what Brent Hickman has to say about how one of the largest fuel-hauling fleets in the country is using AI.

Read More →
Maintenanceby News/Media ReleaseJanuary 16, 2026

ACC Fleet Solutions Launched to Address Recurring Heavy-Duty Truck Parts Failures

ACC Fleet Solutions is a new offering that allows fleets to address recurring part failures with higher-performing, custom-engineered solutions developed at no up-front cost.

Read More →
Ad Loading...
Henrickson aftermarket parts.
Maintenanceby News/Media ReleaseJanuary 15, 2026

Hendrickson to Highlight Aftermarket Portfolio at HDAW 2026

In addition to suspension components, Hendrickson will highlight a range of complementary systems and technologies at HDAW 2026.

Read More →