What is the CARB Clean Truck Check?
The Clean Truck Check (CTC) is a California Air Resources Board (CARB) program that requires periodic emissions compliance testing for heavy-duty diesel vehicles operating in California. It replaced the older Periodic Smoke Inspection Program (PSIP) and uses the truck's onboard diagnostics (HD OBD) to verify the emissions system is working correctly.
If your truck operates in California and weighs more than 14,000 lbs, chances are you're in the program — and you have to submit passing test results to CARB on a regular schedule to stay legal.
Who has to comply?
- Non-gasoline heavy-duty vehicles with a GVWR over 14,000 lbs operating in California
- Both California-registered and out-of-state trucks that drive into California
- Owner-operators, fleets, agriculture, construction, delivery, and municipal vehicles
NextGen tests 2013 and newer diesel trucks using the official HD OBD Clean Truck Check test. Older trucks that require the opacity/smoke test method are not something we perform.
Deadlines & testing frequency
Compliance testing is required roughly every 6 months. Your exact deadline is shown in the CTC-VIS portal for each vehicle.
California-registered trucks must be compliant before DMV will process registration renewal.
Missing a deadline can trigger DMV registration holds, referral for enforcement, and daily penalties. We recommend scheduling testing at least a few weeks before your compliance window closes.
CARB compliance fees
CARB charges an annual compliance fee per vehicle that must be paid in the CTC-VIS portal before your testing result can be reported. That fee is paid directly to CARB, not to the tester. Our mobile HD OBD testing fee is separate and is what you pay us to come to your location and perform the test.
What is HD OBD testing?
Heavy-Duty On-Board Diagnostics (HD OBD) testing plugs into the truck's diagnostic port and reads the emissions system's health data — DTCs, readiness monitors, and MIL status. It is the official CARB Clean Truck Check method for 2013 and newer heavy-duty diesel vehicles.
The test itself is quick per truck. What matters is that the ECM has completed its readiness monitors and has no unresolved emissions-related trouble codes. If the truck fails, you'll need to have the underlying issue repaired at a qualified diesel shop before we can retest.
The CTC-VIS portal
CTC-VIS (Clean Truck Check — Vehicle Inspection System) is CARB's online portal where you register your vehicles, pay compliance fees, and track testing status. Every truck in the program must be registered there.
Before we arrive to test, your truck should already be in CTC-VIS with the compliance fee paid. Need help? See our step-by-step CTC-VIS portal guide.
Step-by-step: how to stay compliant
- 1Register in CTC-VISCreate your account and add every heavy-duty diesel vehicle you own or operate in California.
- 2Pay the annual compliance feePay CARB's per-vehicle compliance fee inside CTC-VIS before your testing window.
- 3Book HD OBD testingSchedule mobile testing with NextGen — we come to your yard, job site, or driveway.
- 4Pass the testWe plug into the truck's HD OBD port, verify readiness monitors, and confirm no active emissions codes.
- 5Results reported to CARBPassing results are submitted through the official reporting process and tied to the VIN. You get certification documentation for your records.
- 6Repeat on scheduleMost trucks test twice per year. Watch CTC-VIS for your next deadline.
Penalties for non-compliance
The fastest way to avoid all of that is to test on time. Book your mobile testing a couple weeks before your CTC-VIS deadline and you'll never lose truck downtime to registration issues.
Why mobile Clean Truck Check testing?
Ready to schedule your CARB Clean Truck Check?
Mobile HD OBD testing across the Inland Empire. We come to you — most trucks tested same-week.