Motorhome Clean Truck Check: RVs over 14,000 lb

Short answer: Diesel and alternative-fuel motorhomes over 14,000 lb GVWR can fall under California's Clean Truck Check program, including many Class A diesel pushers and larger Super C motorhomes. Whether your specific RV is covered is CARB's call, so check CARB's rules or CTC-VIS for your vehicle. If it is covered, a mobile tester can test it where it is parked.

Does my diesel motorhome need Clean Truck Check?

It might. Clean Truck Check covers most diesel and alternative-fuel vehicles over 14,000 lb gross vehicle weight rating (GVWR) that operate in California, and motorhomes over that rating can be included where they fall under the program.

Two questions get you most of the way:

1. Is the GVWR over 14,000 lb? Look at the weight label on the driver's side, usually on the door, door jamb or near the driver's seat. Many Class A diesel pushers and big Super C coaches are over the line. Smaller Class C and Class B motorhomes usually are not.
2. Is the engine diesel or alternative fuel? Clean Truck Check is built around diesel and alternative-fuel engines.

If both answers are yes, look the motorhome up in CARB's CTC-VIS system and check CARB's rules for your vehicle. That is where you will see whether it must be reported, tested and paid for.

Are RVs exempt from Clean Truck Check?

Not as a blanket rule. Being a motorhome rather than a work truck does not on its own take a vehicle out of the program. CARB's rules decide whether a particular RV is covered or has special treatment. We don't guess on that, and we recommend you don't either. Check CARB's rules, CTC-VIS, or our exemptions guide for what to ask.

Which test does a motorhome need?

The test depends on the engine, not on the coach. It is the same as for any other heavy-duty vehicle:

• 2013 and newer diesel engines: CARB-verified OBD test. The tester connects to the vehicle's diagnostic system and checks for emissions faults and readiness.
• 2012 and older diesel engines without OBD: smoke opacity test plus a visual inspection.
• 2018 and newer alternative-fuel engines: CARB-verified OBD test.
• 2017 and older alternative-fuel engines without OBD: visual inspection.

Use the engine model year, which can differ from the year the coach was finished.

OBD test or smoke test for my motorhome?

If your diesel pusher has a 2013 or newer engine, expect an OBD test. An older diesel without OBD gets the opacity test and visual inspection. RV OBD testing works just like truck OBD testing.

Out-of-state motorhomes in California

Registration state does not decide coverage. Clean Truck Check applies to covered vehicles that operate in California, including out-of-state and international vehicles. If you winter in Southern California or travel through the state in a big diesel coach, check CARB's rules for your vehicle and look it up in CTC-VIS. Our post on out-of-state trucks explains how this works for non-California registrations.

Motorhome CTC-VIS registration

Covered vehicles are reported in CARB's CTC-VIS system. The owner pays CARB's annual compliance fee per vehicle there. The amount is set by CARB and shown in CTC-VIS. You can also see your deadlines there. Our CTC-VIS registration guide walks through account setup.

Most covered vehicles currently test twice a year. Under CARB's original rule, OBD-equipped vehicles move to four tests a year from October 1, 2027, and a bill has proposed cutting testing to once a year, so check CTC-VIS for your own schedule.

For California-registered vehicles, missing a deadline can lead to a DMV registration hold. CARB can also issue citations and penalties.

Getting ready for a motorhome test

1. Confirm GVWR and engine year. Note them before you book.
2. Check the dash. A check engine light on, or readiness monitors not set, can cause an OBD test to fail. See readiness monitors and the check engine light.
3. Fix known emissions faults first. DPF and emissions faults are common reasons for a fail. Deleted or tampered emissions equipment fails and is illegal.
4. Pick a spot. The coach needs to be somewhere the tester can reach it and run the engine.
5. Have your CTC-VIS details handy. It speeds up the visit.

If the motorhome fails, it needs repair and then a retest. We don't do repairs, but we explain what the result means so your mechanic knows where to start. See what to do after a failed test.

What happens during a mobile motorhome test

The visit is simple. The tester confirms the vehicle and VIN, then runs the test that fits the engine. For an OBD test, that means connecting to the diagnostic system with CARB-verified equipment while you stay with your coach. For an older diesel, it means a smoke opacity test plus a visual inspection, so the engine needs to run. Once it's done, you get the result in plain English and your next due date. If you'd like, we'll send a reminder before the next one.

Mobile motorhome testing in Southern California

Driving a 40-foot coach to a test site is a hassle. Diesel Dynamix tests on site. We come to your home, and if your RV is at a storage lot or RV park, ask us about testing there when you book. We serve the Inland Empire, San Diego, Los Angeles, Orange County, Long Beach and El Centro, including Riverside, San Bernardino and San Diego.

How Diesel Dynamix helps

Diesel Dynamix is an independent mobile testing service, not CARB or a government agency. For motorhome owners we:

• Run the right test for your engine where your coach is parked.
• Explain the result in plain English and give you the next due date.
• Help with CTC-VIS questions and send reminders.

Call or text (858) 342-8328, message us on WhatsApp, or book a test.