What Is the Clean Truck Check?

The California Air Resources Board (CARB) has implemented the Clean Truck Check (HD I/M) program to reduce emissions from heavy-duty vehicles operating in the state. If you operate any diesel, hybrid, or alt-fuel vehicle over 14,000 lbs in California, this program applies to you—whether you’re a fleet manager, government agency, or a single-truck operator.

Who Must Comply?

• Diesel, hybrid, or alt-fuel vehicles over 14,000 lbs GVWR
• Vehicles operating on California roads — regardless of registration state
• Owner-operators, commercial fleets, transit, utility, and government vehicles
• Out-of-state and DMV-exempt vehicles (must follow VIN-based deadline schedule)

Compliance Deadlines

Vehicles must pass a compliance test twice per year (semi-annually). For CA-registered trucks, deadlines match DMV renewal dates. Out-of-state vehicles follow a schedule based on the last digit of the VIN.

Tests can be submitted up to 90 days before the due date. For example, if your deadline is February 1, 2025, your testing window opens November 3, 2024.

What Testing Is Required?

• OBD-equipped vehicles (2013+ diesel, 2018+ alt-fuel): Must pass an emissions scan using a CARB-certified OBD device such as Silver Snap, HEM Data, or Noregon.
• Non-OBD diesel vehicles (pre-2013): Require an opacity (smoke) test using SAE J1667 standards + visual inspection of emissions equipment.
• Non-OBD alt-fuel vehicles (pre-2018): Require only a visual inspection of emissions controls.

Fees & Submissions

All vehicles must be enrolled in CARB’s CTC-VIS database. Before operating in California, you must:

• Pay the annual compliance fee (approx. $31.18 per vehicle for 2025)
• Submit a passing emissions test through the CTC-VIS portal
• Ensure all reporting is accurate and current

What Happens If You Don’t Comply?

• DMV registration holds (CA-registered vehicles)
• Denial of entry at seaports, intermodal railyards, and enforcement zones
• Fines, penalties, and citations issued by CARB and CHP
• Potential denial of loads, job site access, or contractor eligibility

Coming Soon: Quarterly Testing

Beginning January 1, 2027, OBD-equipped vehicles will shift to quarterly testing. Now is the time to establish systems and service providers who can keep you ahead of schedule.

Let Ferro Consulting Help You Stay Compliant

From CTC-VIS registration to test scheduling and mobile inspections, we help you meet California Clean Truck Check requirements quickly and confidently.