The California Air Resources Board (CARB) has implemented the Clean Truck Check to ensure heavy-duty vehicles operating in California maintain well-functioning emissions control systems. Here is what fleet managers and owner-operators need to know.

Who Needs to Comply?

The regulation applies to nearly all non-gasoline vehicles with a Gross Vehicle Weight Rating (GVWR) greater than 14,000 pounds that operate on California public roads. This includes:

In-state commercial fleets
Out-of-state trucks traveling into California
Owner-operators
Diesel RVs and motorhomes
Agricultural vehicles
Public agency vehicles

Testing Schedule & Deadlines

Compliance deadlines are tied to the vehicle's DMV registration expiration date. The frequency of testing depends on the vehicle type:

Commercial Trucks

Semi-Annual

Testing is required twice per year (every 6 months) for most commercial operations.

RVs & Ag Vehicles

Annual

Testing is required once per year for diesel motorhomes and registered agricultural vehicles.

Test Types: OBD vs Opacity

The type of test your vehicle requires depends on the engine model year and fuel type:

2013+ Model Year Diesel Engines: Require an On-Board Diagnostics (OBD) data download. We plug into the vehicle's diagnostic port and capture emissions data, which is then securely uploaded to CARB.
Pre-2013 Diesel Engines: Require a visual inspection of emissions equipment (like the DPF) and a tailpipe opacity (smoke) test.

Penalties for Non-Compliance

Ignoring the Clean Truck Check will result in immediate consequences for your fleet:

DMV Registration Block: CARB will place a hold on your vehicle, preventing you from renewing your DMV registration.
Financial Penalties: Fines start at $250 per day for operating a non-compliant vehicle in California.
Fleet Grounding: Unregistered vehicles cannot legally operate, causing massive dispatch issues and lost revenue.

How to Check Your Status

You can verify your compliance status in the official CTC-VIS (Clean Truck Check Vehicle Inspection System) database. If you have a hold, you need a certified test immediately. Our CTC-VIS registration guide walks you through the system step by step.

Ready to get compliant? View our mobile testing pricing or schedule a test today. You can also visit our Clean Truck Check Knowledge Hub to learn more about 2026 CARB requirements and the penalties for non-compliance.

CARB Compliance Guide