Short answer: Take CARB's free online tester training (six videos), create a tester account in CTC-VIS, pass the exam there, buy a CARB-certified OBD device (and a SAE J1667 smoke meter if you want to test older diesels) and start testing. Your credential is valid for two years; to renew, retake the course and exam. Fleet owners can get credentialed to test their own trucks.
Five steps
- Take the training. CARB's course is free and online; the six training videos are on YouTube.
- Create a tester account in CTC-VIS (cleantruckcheck.arb.ca.gov).
- Pass the exam in your CTC-VIS tester account. You receive a Certificate of Completion with an eight-character Tester ID, unique to you.
- Buy equipment: a CARB-certified OBD device for 2013+ diesel and 2018+ alternative-fuel trucks, and a SAE J1667 smoke meter if you will test diesel 2012 and older.
- Start testing. Submit results through CTC-VIS (OBD results from a credentialed tester's telematics device upload automatically).
Equipment
| Test | Equipment | Examples |
|---|---|---|
| OBD (handheld) | CARB-certified OBD test device | RA Consulting Silver Snap-Tool, HEM Data DAWN OBD Inspector, Noregon Truck Check Up, DG Technologies DPA INSPECT, Opus Clean Truck kit |
| OBD (telematics) | CARB-certified telematics device | Geotab GO9, Pacific Track PT40, Zonar V4/VT4, Samsara VG, Verizon Connect (Xirgo), Motive Vehicle Gateway |
| Smoke opacity | SAE J1667 smoke meter | — |
Check CARB's certified-device list before buying; certifications carry an Executive Order number (format IM-00X-000X-X).
Who becomes a tester
- Fleets and owner-operators who want to test their own trucks on their own schedule. Self-testing is allowed only for credentialed testers.
- Repair shops, dealers and smog stations adding a service their truck customers need twice a year (four times a year for OBD trucks from October 2027).
- Mobile testers who visit yards, distribution centers and job sites.
Testers set their own prices. Published California prices are usually $50–$135 for an OBD test and $190–$200 for smoke opacity. See the cost guide.
Getting customers
CARB keeps a public "for hire" tester list. Listing is optional: you opt in with the "for hire" setting in your CTC-VIS tester account. CTC Finder is built from that list (2,867 testing businesses in California), so once you opt in, your business appears here after our next monthly refresh. You can then claim your listing to add hours, prices and service area, or get featured at the top of your city page.
Sources
- CARB, How to become a Clean Truck Check credentialed tester
- CARB, HD I/M tester training course and exam
- CARB, Tester training and examination fact sheet
- CARB, CARB-certified OBD test devices
- CARB, Find a CTC tester
Frequently asked questions
How much does it cost to become a Clean Truck Check tester?
CARB's training course and exam are free. The main cost is equipment: a CARB-certified OBD device, plus a smoke meter if you will do opacity tests.
How long is a Clean Truck Check tester credential valid?
Two years from the date you passed the exam. To renew, retake the course and the exam.
Can a fleet test its own trucks?
Yes, if the person doing the test is a CARB-credentialed tester using a certified device.
How do I get listed on CARB's tester list?
Turn on the "for hire" setting in your CTC-VIS tester account. Listing is optional.
CTC Finder is an independent directory and is not affiliated with CARB. Rules change; check CARB's Clean Truck Check pages for the official version.