Fleet Clean Truck Check Compliance Program Guide

Short answer: fleet Clean Truck Check compliance comes down to four things: every covered truck is reported in CARB's CTC-VIS system, each one has its compliance fee paid, each one is tested inside its window, and someone owns the schedule. A recurring on-site testing program makes that much easier. Diesel Dynamix tests fleets at their yards and terminals across Southern California, with per-truck pricing and records per VIN.

What does emissions compliance mean for a California trucking company?

For most diesel and alternative-fuel vehicles over 14,000 lb GVWR that operate in California, it means meeting CARB's Clean Truck Check program. That includes out-of-state and international trucks. Non-compliance can lead to DMV registration holds for California-registered vehicles, plus CARB citations and penalties. See Clean Truck Check penalties and enforcement.

Most covered vehicles currently test twice a year. Under CARB's original rule, OBD vehicles move to four tests a year from October 1, 2027. A bill has proposed cutting testing to once a year, so this may change. Either way, a fleet with dozens of trucks has a lot of deadlines to track.

How does fleet reporting work in CTC-VIS?

CTC-VIS is CARB's system where owners report vehicles and pay the annual compliance fee for each one. For a fleet, that means:

• Every covered truck is added to the account with the correct VIN
• The fee is paid per vehicle. The amount is set by CARB and shown in CTC-VIS
• Each truck's deadlines and compliance status are shown there
• Test results from your tester show up against each VIN

Our CTC-VIS registration guide walks through setup, and the compliance fee guide explains the fee. Check CTC-VIS after each round of testing to confirm every truck shows the result.

Who handles Clean Truck Check on a leased truck?

It depends on your lease. The owner and the operator, whether that is a lessor, a motor carrier or an owner-operator leased onto a carrier, should agree in writing on who reports the truck in CTC-VIS, who pays CARB's compliance fee and who books and pays for testing. CARB's rules decide who is legally responsible, so check CARB's Clean Truck Check page for how they treat leased vehicles.

Practical tip: put Clean Truck Check in the lease or onboarding checklist, next to registration and insurance, so nobody assumes the other side has it.

Do farm trucks need an emissions test in California?

Agricultural vehicles over 14,000 lb can fall under the program. Whether a specific farm truck must test, or qualifies for any exemption, depends on CARB's rules for that vehicle. Check CARB before skipping a test. Our exemptions guide covers the common questions.

If your farm trucks do need testing, we can test them on site, including in the Imperial Valley. See El Centro.

How do I set up a fleet compliance program?

1. List every vehicle. Include VIN, plate, GVWR, fuel type and engine model year. That tells you which test each truck needs:
- 2013 and newer diesel and 2018 and newer alternative fuel: CARB-verified OBD test
- 2012 and older diesel without OBD: smoke opacity test plus visual inspection
- 2017 and older alternative fuel without OBD: visual inspection
2. Match the list to CTC-VIS. Make sure every covered truck is reported and every fee is paid.
3. Group trucks by testing window. Batching trucks with similar deadlines means fewer visits.
4. Set a recurring visit schedule with your tester.
5. Fix faults between tests. Check engine lights, readiness monitors and DPF problems are the usual reasons fleet trucks fail. See readiness monitors and the check engine light.
6. Keep records per truck. Save each result and next due date by VIN.
7. Review after each visit. Confirm results in CTC-VIS and line up retests for any failures.

What records should a fleet keep?

At a minimum, for each VIN:

• Test date, test type and result
• Next due date
• Any failures, the repair done and the retest date
• CTC-VIS status and fee payment confirmation

Good records make it easy to answer a DMV hold or CARB question quickly.

Why use recurring on-site fleet testing?

Driving a whole fleet to a test site costs driver hours, fuel and truck time. On-site testing keeps trucks in the yard and lets one visit cover many trucks. Early-morning visits mean trucks can be tested before they roll out. With more frequent testing possible from 2027, a set schedule also avoids a scramble each window. See how often trucks need Clean Truck Check.

How Diesel Dynamix helps

We run fleet testing programs at yards, terminals, warehouses, jobsites and port-area lots across Southern California, including Los Angeles, Long Beach, the Port of Los Angeles, the Inland Empire, Orange County and San Diego.

• Recurring fleet visits, including early-morning visits
• Per-truck pricing for fleets, quoted by phone or WhatsApp
• OBD and smoke opacity tests on site
• Records per truck and VIN, next due dates and reminders
• Help with CTC-VIS questions and plain-English results

We do not do repairs. If a truck fails, we explain why so your shop can fix it, then we retest. Diesel Dynamix is an independent testing service, not CARB.

See fleet testing, then book a fleet visit, call or text (858) 342-8328 or email service@dieseldynamix.com for a quote.