Do I Need a CARB Clean Truck Check Test in 2025?
Quick eligibility guide for trucks, RVs, and fleets operating in California.
California’s Clean Truck Check (HD I/M) program is live. If you operate a non-gasoline heavy-duty vehicle over 14,000 lbs GVWR on California roads, you likely need periodic emissions testing—separate from light-duty Smog Check. This page gives you the fast answer, with links to our 2025 CARB Guide and our Clean Truck Check testing service in Glendora.
Who Needs a Clean Truck Check in 2025?
Operates in California: Your vehicle runs on CA public roads (even if registered out of state).
Non-gasoline: Diesel, CNG, propane, or hybrid (*not* zero-emission).
GVWR > 14,000 lbs.
Exempt highlights: Zero-emission heavy-duty vehicles and motorhomes registered outside California are not subject to Clean Truck Check. California-registered motorhomes are included (see testing frequency below).
What Type of Test Will I Need?
CARB sets the test method by your engine model year (check the engine emission control label):
OBD-equipped engines — Diesel 2013+ and Alt-fuel 2018+: OBD scan using a CARB-certified device by a credentialed tester.
Non-OBD engines — Diesel ≤2012: SAE J1667 smoke opacity test *and* a visual inspection. Alt-fuel ≤2017: visual inspection only.
Note: Your tester submits results electronically to CARB; you don’t upload them yourself.
How Often Is Testing Required?
Most vehicles: Semi-annual (every 6 months).
California-registered motorhomes (recreational/emergency use) and agricultural vehicles: Annual.
Starting Oct 1, 2027: OBD-equipped vehicles move to quarterly testing; motorhomes/ag vehicles remain annual.
Deadlines: CA-registered vehicles follow your DMV registration month. Non-CA registered/DMV-exempt follow the VIN last digit. You’ll see exact dates in your CTC-VIS account.
When Did Testing Start?
Emissions test submissions count from Oct 1, 2024. For deadlines on/after Jan 1, 2025, a passing test is required. You may submit a passing test up to 90 days before your deadline.
Fees & Enforcement
Annual compliance fee: $31.18 per vehicle (for 2025 deadlines), paid in CTC-VIS.
Enforcement: Non-compliance can trigger DMV registration holds and denied port/railyard access.
Quick Examples
2015 diesel day-cab, >14,000 GVWR, out of state but driving into CA → YES (OBD test; semi-annual deadlines).
CA-registered motorhome, 2006 diesel → YES (annual; opacity + visual).
Non-CA motorhome, 30,000 GVWR → NO (not subject).
Heavy-duty gasoline truck, >14,000 GVWR → NO (Clean Truck Check covers non-gasoline HD vehicles).
2019 CNG refuse truck → YES (OBD test).