Questions & answers
Before your next
California run.
Understand the basics, then check your specific truck.
Coverage & eligibility
Does this apply to out-of-state trucks?
It can. California Clean Truck Check generally covers non-gasoline vehicles over 14,000 lb GVWR operating on California public roads, including vehicles registered elsewhere. Exemptions apply. Your home state alone does not determine eligibility.
Which engine model years use OBD testing?
2013-and-newer diesel engines and 2018-and-newer alternative-fuel engines are the OBD categories. Engine year may differ from truck year. The certified device, protocol and cable must also match.
Can you tell compatibility from my VIN alone?
No. A VIN identifies the vehicle, but it does not alone confirm the installed engine, emissions configuration or supported diagnostic protocol. Use our preliminary check, then confirm the engine label and connection.
What about an older engine?
Earlier diesel engines generally require smoke-opacity and visual inspection. Earlier alternative-fuel engines use visual inspection. A remote OBD device is not a substitute for the required non-OBD method.
Is this a testing requirement in all 50 states?
These pages serve operators based nationwide who work California routes. They do not describe an identical emissions mandate in every state.
Are there exempt vehicles or special schedules?
Yes. Vehicle use and category matter, including certain exemptions and annual schedules. Check the official CARB guidance and your vehicle record instead of applying one fleet-wide assumption.
Device, connection & testing
Is remote testing different from a technician’s OBD test?
The delivery method changes: a connected device collects and submits diagnostic data through the service instead of a technician’s test session. Emissions and readiness requirements still apply.
Do I need a 9-pin or 16-pin connection?
That depends on the vehicle and supported configuration. Share the engine year, make and port photo. A physically matching connector alone does not establish compatibility.
Can I keep my existing ELD?
Tell us what already uses the diagnostic port before ordering. Cable sharing and installation need to be checked for your specific equipment. Do not assume every splitter is suitable.
Does it need power and connectivity?
Yes. The device needs a correct installation, power and a working connection for remote service. If it goes offline, investigate the connection before assuming a scheduled test was completed.
How often does the vehicle need a test?
Most subject vehicles currently test twice a year. CARB schedules most OBD vehicles to move to four tests a year on October 1, 2027; special annual categories remain. Use the deadlines shown for your vehicle in CTC-VIS.
Can I request a test after an NST notice?
An NST notice has its own deadline. Read the notice and arrange the required test promptly; do not wait for the next periodic test. Contact E-ZCARB to arrange supported on-demand testing.
Results, repairs & registration
What happens if I fail?
Diagnose and repair the reported issue, then arrange a retest. A subscription does not repair an emissions fault or change the passing criteria.
What does Not Ready mean?
The diagnostic system has not completed the required checks. Recent repairs, battery disconnection or cleared codes may be relevant. Follow manufacturer guidance to restore readiness, then retest.
Should I clear fault codes before testing?
Clearing codes is not a repair and can reset readiness. CARB advises against code clearing or battery disconnection close to testing.
Where are the official results?
Use your CTC-VIS vehicle record to check official results. Your E-ZCARB portal organises test activity and history; an online device status by itself is not a passing test.
Do I still need to register and pay CARB fees?
Yes. Vehicle reporting, government fees and applicable deadlines remain the owner’s responsibility. They are separate from purchasing a testing subscription.
Will buying the device remove a DMV hold?
Not by itself. Read the hold reason and resolve the missing reporting, payment, testing or other requirement. Processing time and repair needs vary; same-day clearance is not promised.
Plans, fleets & support
What is the first-year and renewal price?
Your proposal is based on vehicle compatibility, fleet size and the service you need. Send a request to discuss equipment, setup, support and commercial terms directly with E-ZCARB.
Do retests cost extra?
Retest arrangements are set out in your individual service proposal. Resolve the fault or readiness issue before requesting a retest.
What if required testing frequency increases?
Follow the schedule applicable to your vehicle. Discuss the testing scope and any changes with E-ZCARB as part of your individual service arrangement.
Who owns the device?
Equipment ownership and ongoing service arrangements are specified in your individual proposal.
Can one subscription cover several trucks?
Each truck needs its own compatible setup and testing record. Contact us to arrange a proposal for your vehicle mix.
Can I become a partner?
Yes, explore the partner enquiry page for referral and service-provider opportunities. Partner status is not CARB tester accreditation. Commercial terms are agreed separately.