California’s Truck and Bus Regulation and Clean Truck Check program establish separate but related requirements for heavy-duty vehicles operating in the state.

The Truck and Bus Regulation requires most diesel-powered trucks and buses with a gross vehicle weight rating greater than 14,000 pounds to use a 2010 or newer model-year engine and emissions system, unless an exemption or approved compliance option applies.

Clean Truck Check adds ongoing reporting, annual fee and periodic emissions testing requirements for nearly all non-gasoline heavy-duty vehicles over 14,000 pounds GVWR operating on California public roads.

Advanced Emission helps fleet operators, owner-operators and qualifying motorhome owners understand these requirements, complete Clean Truck Check testing and address emissions-related service needs.

The Clean Truck Check program applies to all heavy-duty diesel vehicles operating in California with a gross vehicle weight rating (GVWR) of over 14,000 pounds, including:

Commercial trucks and fleets
Diesel motorhomes (recreational vehicles)
Agricultural vehicles and equipment
Out-of-state trucks operating on California public highways

Requirements and exemptions differ by vehicle type and use.  Vehicle owners should review the information and deadlines shown in their CTC-VIS account.

Need help with Clean Truck Check registration, testing, or reporting? Call us at (559) 579-1450.

To remain compliant, vehicle owners must:

1. Report qualifying vehicles in the Clean Truck Check Vehicle Inspection System (CTC-VIS).

2. Pay the annual compliance fee for each vehicle. The fee is $32.13 for compliance deadlines in 2026 and may be adjusted annually.

3. Complete the required emissions testing by each vehicle’s deadline.

4. Resolve any outstanding enforcement violations.

Most qualifying vehicles require testing every six months.  Qualifying agricultural vehicles and California-registered recreational or emergency-use motorhomes generally require testing once per year.

A CARB-credentialed tester submits the test results to CARB.  Passing tests may be submitted up to 90 days before the vehicle’s compliance deadline.  Always check CTC-VIS for the specific deadlines assigned to each vehicle.

Advanced Emission provides Clean Truck Check testing performed by CARB-credentialed testers.  Our team can also help vehicle owners understand their requirements, review CTC-VIS information, and address emissions-related issues.  Here's how we help:

Credentialed Testing Services
We perform Clean Truck Check emissions testing using CARB-approved testing equipment.

CTC-VIS Test Reporting
Our credentialed testers submit completed test results directly to CARB through CTC-VIS.

OBD and Smoke Opacity Testing
Depending on the engine and model year, testing may involve an OBD scan or a smoke opacity test and visual inspection of the emissions-control equipment.

Compliance Assessments
Our team can help identify applicable requirements and prepare vehicles for upcoming testing deadlines.

Diagnostics, Repairs, and Maintenance
From DPF cleaning to part replacements, we ensure your vehicles pass testing and stay operational.

Whether you manage a fleet of trucks, operate diesel motorhomes, or run agricultural vehicles, we're your trusted partner for compliance.

California-registered diesel motorhomes with a GVWR greater than 14,000 pounds may be subject to Clean Truck Check, even though personal-use motorhomes are generally not subject to the Truck and Bus Regulation.

Qualifying motorhomes used for recreation or emergency occupancy generally require emissions testing once per year.  Owners must also report the vehicle in CTC-VIS and pay the applicable annual compliance fee.

Advanced Emission provides Clean Truck Check testing and reporting assistance for qualifying diesel motorhomes at our Fresno facility.

1. Check Your Requirements: Review your vehicle information and deadlines in CTC-VIS.

2. Schedule Testing: Call (559) 579-1450 to schedule Clean Truck Check testing for your fleet, truck, or qualifying motorhome.

3. Allow Time for Repairs: A passing test may be submitted up to 90 days before the deadline, allowing time to address any problems.

4. Stay Current: Monitor CTC-VIS for testing deadlines, annual fees, and open enforcement actions.

Advanced Emission provides credentialed testing, reporting assistance, and emissions-related services to help keep vehicles compliant and road-ready.

Visit the CARB website for helpful information.

Read our blog for information about recent updates and news. 

Contact us for testing and reporting assistance at (559) 579-1450.