Frequently Asked Questions
- Knowledge ID
- KO-CTC-0005
- Program Area
- Faq
- Topic Type
- Faq
- Reading Time
- 1 min read
- Last Reviewed
- Jul 17, 2026
- Applies To
- Owner Operator, Fleet Manager, Service Provider — On Road Heavy Duty Diesel, Motorhome Rv, Agricultural, Specialty On Road — Both registration
- Official Source
- https://ww2.arb.ca.gov/clean-truck-check-overview-fact-sheet
Quick Answer
California's Clean Truck Check program often raises questions about vehicle eligibility, testing, compliance fees, remote monitoring, and registration requirements. The questions below address the most common topics and link to more detailed Knowledge Objects where appropriate.
This page answers some of the most common questions about California’s Clean Truck Check program.
It is intended as a living resource — a primary entry point into the Knowledge Platform that continues to grow as new questions arise through customer calls, emails, support requests, field installations, real-world compliance situations, and changes to CARB regulations. Where a question needs more depth, it links to a more detailed Knowledge Object.
Frequently Asked Questions
- What is California Clean Truck Check?
- California Clean Truck Check is the state's heavy-duty vehicle inspection and maintenance program designed to ensure qualifying diesel vehicles continue to meet emissions standards throughout their service life. See also: What Is Clean Truck Check? (KO-CTC-0001).
- Who has to comply?
- Program eligibility depends on several factors, including vehicle type, engine configuration, registration status, and CARB requirements. See also: Who Must Comply? (KO-CTC-0002).
- Do I still have to pay the annual compliance fee?
- Yes. The annual compliance fee is separate from emissions testing. Completing one requirement does not satisfy the other.
- How often does my vehicle need to be tested?
- Testing frequency depends on the vehicle and CARB's current program requirements. Owners should verify the testing schedule that applies to their specific vehicle.
- What happens if my vehicle fails?
- If a vehicle does not meet the applicable emissions requirements, repairs may be necessary before the vehicle can successfully complete the required testing process. Vehicle owners should follow CARB's guidance regarding repairs and any required retesting.
- What is Remote Monitoring?
- Remote Monitoring is a CARB-approved compliance option for qualifying vehicles that allows required emissions testing to occur during normal vehicle operation using an approved monitoring device. See also: How Remote Monitoring Works (KO-CTC-0006).
- Can every vehicle use Remote Monitoring?
- No. Only vehicles that meet CARB's eligibility requirements may participate in Remote Monitoring.
- Do out-of-state vehicles have to comply?
- Yes. Certain out-of-state vehicles operating in California are also subject to Clean Truck Check requirements.
- Where can I find official program information?
- The California Air Resources Board (CARB) maintains the official Clean Truck Check resources, which include eligibility requirements, testing information, compliance guidance, and current program updates.