Frequently Asked Questions (FAQ)

NorCal CARB Mobile – Clean Truck Check (HD I/M) Services

1. What is the Clean Truck Check (HD I/M) program?

The Clean Truck Check, formerly known as the Heavy-Duty Inspection and Maintenance (HD I/M) program, is a California Air Resources Board (CARB) requirement for most diesel and alternative-fueled vehicles with a GVWR over 14,000 lbs. It includes emissions compliance testing, OBD data reporting, and periodic inspections.

2. Which trucks are required to participate in the Clean Truck Check program?

If your truck is over 14,000 lbs GVWR and operates in California, you are likely subject to the program. This includes Class 4–8 trucks, both in-state and out-of-state vehicles that enter California. Even DMV-registered non-diesel vehicles like CNG and LNG trucks may be subject depending on year and setup.

3. How often do I need to test my truck?

Most trucks are required to be tested twice per year, though newer trucks follow a phased-in schedule:

  • 2013 and newer OBD-equipped vehicles: OBD data reporting required.

  • Pre-2013 trucks: Periodic smoke opacity and visual testing.

  • Newer vehicles (2023+): Some may be exempt from reporting for the first few years.

Visit CARB’s testing schedule or contact us for details.

4. Do I need to submit OBD data or get a smoke test?

It depends on the year of your vehicle:

  • 2013 and newer: Must submit OBD data through a CARB-approved tester.

  • Older trucks (typically pre-2013): Must complete opacity testing + visual inspection.

NorCal CARB Mobile can help determine which applies to your fleet.

5. How do I report my test to CARB?

After we perform your test, we electronically submit the OBD or opacity report directly to CARB via the Clean Truck Check Vehicle Inspection System (CTC-VIS). You’ll receive confirmation and documentation for your records.

6. What cities and regions do you service?

We proudly service the Sacramento Metro Area, including:

  • Sacramento

  • Roseville

  • Elk Grove

  • Rancho Cordova

  • West Sacramento

  • Woodland

  • Lodi

  • Stockton

  • Auburn

  • Fairfield

We also travel to nearby job sites, yards, truck stops, and gas stations to keep your trucks in compliance without disrupting your route.

7. Can you test my truck while I’m getting fuel or parked at a truck stop?

Yes. Our mobile team is equipped to test trucks while you’re refueling, on break, or parked at a rest stop. We perform quick, on-the-spot inspections and OBD reads with minimal downtime.

8. Do I need to bring my truck somewhere?

No. We come to you. Whether you're parked at a jobsite, yard, or fueling station, NorCal CARB Mobile handles testing on location—saving you time and avoiding unnecessary miles.

9. How much does a Clean Truck Check test cost?

Our pricing is competitive and straightforward:

  • As low as $50 per truck

  • Discounts available for fleets or multi-truck bookings

  • No hidden fees; includes submission to CARB

Contact us for bulk or recurring testing options.

10. What happens if I miss a test deadline?

Failure to comply with Clean Truck Check requirements can result in registration holds and fines from CARB. Stay ahead by scheduling your test early—we offer reminders and fleet tracking to avoid penalties.

11. Do you offer fleet testing services?

Yes. We specialize in fleet compliance, offering on-site testing for multiple vehicles in a single visit. We’ll help manage your testing schedule and ensure every unit meets CARB deadlines.

12. How long does a test take?

Most inspections take 5 to 15 minutes per truck, depending on OBD response or test type. We work quickly to get you back on the road without delay.

13. Are rental and lease trucks required to test too?

Yes, if a leased or rented truck is operating in California and over 14,000 lbs GVWR, it’s subject to Clean Truck Check regulations. The responsible party (owner or lessee) must ensure compliance.

14. How do I know when my next test is due?

You can check the schedule using your VIN on the CTC-VIS portal, or we can monitor and notify you when it’s time.

15. Why choose NorCal CARB Mobile?

We’re a local, fast-response mobile team focused exclusively on CARB Clean Truck Check compliance. We save you downtime by testing trucks where they are—no shops, no waiting, no detours.