Clean Truck Check and smog stations

Two programs, two agencies

Smog Check is BAR’s program. Clean Truck Check is CARB’s inspection and maintenance program for heavy-duty vehicles. BAR’s Smog Check Manual says diesel vehicles over 14,000 lbs GVWR are exempt from Smog Check, and so are dedicated propane and natural gas vehicles over 14,000 lbs.

Which vehicles it covers

Nearly all diesel and alternative fuel vehicles over 14,000 lbs GVWR that drive on California roads, even when they are registered in another state. That includes government vehicles, buses, hybrids, commercial vehicles, personal vehicles and motorhomes registered in California.

For Clean Truck Check, alternative fuel means natural gas, propane, ethanol, methanol and other fuels that aren’t diesel or gasoline. It does not mean electricity or hydrogen. Zero-emission vehicles, emergency vehicles, military tactical vehicles, historical vehicles and motorhomes registered outside California are not covered.

What truck owners must do

• Report the vehicle and pay its annual compliance fee in CARB’s CTC-VIS system. The fee goes up each year with California’s Consumer Price Index.
• Send a passing emissions test by each compliance deadline. A tester can submit it up to 90 days early.
• Have no outstanding enforcement violations.

CARB also screens trucks on the road. A truck flagged as a possible high emitter gets a Notice to Submit to Testing, and the owner has 30 calendar days to send CARB a passing test.

Who can do the test

Only a CARB credentialed tester. Anyone with basic knowledge of heavy-duty emissions systems can take CARB’s free online tester course. Passing the exam with at least 80 percent gives you a tester ID, good for two years.

Vehicles with OBD get an OBD test. Vehicles without OBD get the SAE J1667 smoke opacity test, which needs a J1667-compatible smoke meter, and an emissions control equipment inspection.

What it means for your smog station

• A heavy diesel is not a smog check. It is exempt from Smog Check.
• Your BAR inspector license doesn’t make you a Clean Truck Check tester. That credential comes from CARB’s course and exam.
• To offer Clean Truck Check tests, you or your staff can take CARB’s free course. CARB keeps a public list of credentialed testers.

SmogScanner marks diesel vehicles over 14,000 lbs Exempt from Smog Check. It doesn’t do Clean Truck Check reporting.