CARB-credentialed mobile OBD and opacity testing for trucks and motorhomes. We come to you, anywhere in California: yard, job site, truck stop or RV park. Results on the spot, sent straight to CARB.
See when your 90-day testing window opens.
Flagged by CARB? You have 30 days. Call us.
Prep your truck so it passes the first time (PDF).
Standard CTC from $65. Fleet admin is free.
You can pass your test up to 90 days before each compliance deadline. Enter your DMV registration expiration date to see your windows.
Enter a date and press Calculate to see each deadline, when its 90-day window opens, and whether it’s open now.
Credentialed, licensed and insured testers bring the Clean Truck Check to you. One call covers the test, the CARB upload and the paperwork, for one motorhome or a whole fleet.
We test where your vehicle already is: shop, yard, job site, truck stop or RV park. No waiting: most tests take 15–30 minutes.
Diesel and alternative-fuel vehicles over 14,000 lbs GVWR, from owner-operators to mixed fleets.
We do lots of motorhomes. They test once a year, and we come to your driveway, storage lot or campground.
For 2013+ diesel and 2018+ alternative-fuel engines. We capture emissions data from the vehicle computer and upload it to CARB.
For older engines: SAE J1667 snap-acceleration smoke test plus visual inspection, with the same equipment the government uses.
We manage your CTC-VIS account at no charge, monitor CARB alerts and keep every vehicle on schedule.
No waiting: you get your emissions report on the spot.
Quotes depend on location and how many vehicles we test on one visit. Fleets pay less per vehicle.
Mobile Smoke Check is a team of CARB-trained compliance testers and inspectors, credentialed for the Clean Truck Check program (formerly Heavy-Duty Inspection and Maintenance). We measure opacity on diesel vehicles over 14,000 lbs using the SAE J1667-201802 standard, with the same light-extinction test equipment the government uses.
We’re certified by the Clean Truck Check Tester Alliance™, hold a California business license, and carry $2,000,000 in liability insurance with a mobile service rider.
Curious about our logo? Read the story behind the two spirals →

Clean Truck Check is CARB’s Heavy-Duty Inspection and Maintenance (HD I/M) program, created under Senate Bill 210 to make sure vehicles’ emissions controls keep working. It applies to diesel and alternative-fuel vehicles over 14,000 lbs GVWR on California roads, including out-of-state trucks and motorhomes.
CARB, California’s clean air agency, oversees the program. Owners register each vehicle in CTC-VIS, pay an annual fee and submit passing tests on schedule. Miss a deadline and the DMV can hold your registration.
Tell us about your vehicles and where they are. We’ll reply with a price and the next available time.
SCMDSC is committed to equal opportunity and non-discrimination for all employees, applicants, and subcontractors. We believe in fostering a diverse and inclusive workplace, free from discrimination.
What this means in practice:
Fairness throughout the employment journey:
At SCMDSC, you can expect fair and objective decisions throughout your employment journey, from the initial application to promotions, compensation, and training opportunities.