California Clean Truck Check: essentials for your truck

Which vehicles are covered?

CARB says the program covers nearly all diesel, alternative-fuel, and hybrid heavy-duty vehicles with a gross vehicle weight rating above 14,000 pounds operating on California public roads, even if registered in another state. Exceptions and category-specific rules exist, so check your vehicle against the official guidance.

Where do I find my deadline?

The deadline that counts for your vehicle appears in your CTC-VIS account under testing details. Do not use another truck's date or assume it always matches DMV registration. Most vehicles on the semiannual schedule must demonstrate compliance every six months; some categories follow another schedule.

CARB allows a passing test to be submitted up to 90 days before the deadline, leaving time for a repair and retest if needed. Check your account and CARB guidance before scheduling.

Testing and preparation

Vehicles with applicable OBD systems are tested with a CARB-certified OBD device. Applicable diesel vehicles without OBD require a smoke-opacity test and a visual inspection of emissions-control equipment. Compliance testing must be performed by CARB-credentialed testers.

If you have a warning light, power loss, or active codes, understand the problem ahead of the test date. We can help review symptoms and the DPF system; confirm the correct compliance test with CARB or a credentialed tester.