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You’re running a business, not studying CARB regulations full-time. But California doesn’t care—if your truck isn’t compliant, you’re looking at fines starting at $1,000 per day and climbing to $75,000. Your registration gets blocked. Your truck sits instead of earning.
That’s where Clean Truck Check compliance comes in. If you operate a heavy-duty diesel truck with a 2013 or newer engine and a gross vehicle weight rating over 14,000 pounds, you need emissions testing. Most trucks require it twice a year. Starting in 2027, some will need it four times annually.
We handle the OBD testing using CARB certified devices, check your emissions control systems, and make sure you’re good to go. You get documentation proving compliance, your registration stays active, and you avoid the kind of penalties that can shut down operations. It’s not exciting work, but it keeps your trucks where they belong—on the road making money, not parked waiting for paperwork.
We operate right here in Lennox, which means we’re in the middle of one of the busiest freight corridors in California. We see the trucks that move goods through the ports, up the 405, across to the Inland Empire. We know what you’re dealing with because we test these vehicles every single day.
Our testers are CARB credentialed—they’ve completed the official training and passed the certification exams required by the state. We use the approved OBD testing equipment for 2013 and newer diesel engines. We stay current on regulation changes because we have to, and because you’re counting on us to get it right the first time.
First, we verify your truck qualifies—2013 or newer model year, over 14,000 pounds GVWR. If it does, we move forward with the Clean Truck Check inspection. If it doesn’t, we’ll tell you straight up and save you the trip next time.
Next, we connect to your truck’s onboard diagnostics system using CARB certified testing devices. We’re pulling data directly from your engine’s computer to check emissions control performance. We’re looking at your diesel particulate filter, your NOx sensors, your regeneration system—all the equipment that keeps your truck from pumping out the pollution that makes up over 50% of California’s mobile-source smog.
If everything checks out, you get your passing certificate submitted to CARB’s system. You’re documented, compliant, and clear for registration. If something’s flagged, we’ll walk you through what needs repair before you can pass. No surprises, no runaround—just the facts about what your truck needs to meet California’s emissions standards.
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You’re getting a full Clean Truck Check inspection performed by a credentialed tester who knows the current CARB requirements for heavy-duty diesel trucks. We test the emissions control systems on your 2013 or newer truck using state-approved OBD scanning equipment. We verify that your diesel particulate filter, selective catalytic reduction system, and other emissions controls are functioning properly.
Here in Lennox, we’re testing trucks that run the I-405, the I-110, and the routes to and from LAX and the Port of Los Angeles. These are high-mileage commercial vehicles operating in stop-and-go conditions that stress emissions systems. We see the real-world wear patterns and know what commonly fails in this environment.
You’ll receive documentation of your test results submitted directly to CARB’s compliance database. That keeps your registration current with the DMV and proves compliance if you’re ever stopped for roadside inspection. Most trucks need this done semi-annually. Some will need it quarterly starting in 2027. We’ll let you know your specific schedule based on your truck’s year and engine type, so you’re never caught off guard by a deadline.
If your truck has a 2013 or newer diesel engine and weighs over 14,000 pounds GVWR, this isn’t optional—it’s California law. The Clean Truck Check program became mandatory with all compliance deadlines on or after January 1, 2025, requiring passing test submissions.
Skip it and you’re facing registration blocks from the DMV. Your truck can’t legally operate in California without current registration. You’ll also risk fines ranging from $1,000 to $75,000 per day for non-compliance, plus up to $10,000 per vehicle per day in some cases.
CARB uses roadside monitoring devices and sends Notice to Submit to Testing letters when they detect potential violations. Once you’re flagged, you have a limited window to get tested and submit passing results. Missing that deadline compounds your problems. So no, this isn’t optional if you want to keep operating legally in this state.
Right now, most qualifying heavy-duty trucks need Clean Truck Check testing twice a year—that’s semi-annual compliance. Your specific testing schedule depends on your truck’s model year and engine type, but plan on every six months as the standard.
Starting October 2027, trucks with OBD-equipped engines—basically 2013 and newer diesel engines—will need testing four times per year. That’s quarterly compliance, which means you’ll be coming in every three months instead of every six.
The testing frequency is tied to your compliance deadlines, which CARB tracks in their system. Miss a deadline and your registration renewal gets blocked until you submit a passing test. We recommend setting reminders well before your due dates, because waiting until the last minute leaves no room for repairs if your truck doesn’t pass on the first attempt.
We connect a CARB certified OBD scanner to your truck’s diagnostic port and pull data directly from the engine’s computer system. We’re not doing a tailpipe test—we’re reading the performance data from your emissions control equipment while it’s been operating on the road.
The scanner checks your diesel particulate filter status, your selective catalytic reduction system, your NOx sensors, and other emissions components. It’s looking for fault codes, system malfunctions, or performance issues that indicate your truck is emitting more pollution than California allows.
The whole process typically takes 30 to 45 minutes if everything’s working correctly. If your systems are functioning properly and there are no stored fault codes indicating emissions problems, you pass. We submit your results to CARB’s database electronically, and you get documentation proving compliance. If there are issues, we’ll explain exactly what’s flagged and what needs repair before you can pass a retest.
You need a CARB credentialed tester using CARB certified testing equipment. Not every smog shop is set up for heavy-duty diesel compliance testing—this is specialized work that requires specific training, certification, and equipment that most passenger vehicle smog stations don’t have.
The tester performing your Clean Truck Check inspection must have completed official CARB training and passed the state certification exam. They need to use approved OBD testing devices specifically designed for heavy-duty diesel engines. Regular smog check equipment for passenger cars won’t cut it.
When you’re looking for a testing facility, verify they’re credentialed for heavy-duty vehicle testing and equipped to handle 2013 and newer diesel trucks over 14,000 pounds. We have the credentials, the equipment, and the experience with these specific compliance requirements. Showing up at a random smog shop that only handles passenger vehicles wastes your time and doesn’t get you the documentation you need.
If your truck fails, we’ll give you a detailed explanation of what’s wrong based on the fault codes and system data we pulled during testing. You’ll know exactly which emissions components aren’t performing correctly—whether it’s your DPF, your SCR system, a sensor issue, or something else.
You’ll need to get those repairs done before you can pass a retest. We can point you toward what needs fixing, but you’ll likely need a diesel mechanic who specializes in emissions system repairs. Once the work is complete, you come back for another test.
Here’s the critical part: your compliance deadline doesn’t change just because you failed. If your testing due date is approaching and you fail, you’re on the clock to get repairs done and pass a retest before that deadline hits. Miss it and your registration gets blocked, which means your truck can’t legally operate. That’s why we recommend testing well before your deadline—it gives you time to handle repairs without losing your ability to work while the truck’s getting fixed.
Testing costs vary by facility, but you’re typically looking at a fee for the inspection service itself. That covers the credentialed tester’s time, the use of CARB certified OBD testing equipment, and the electronic submission of your results to the state database.
Compare that to the cost of non-compliance: $1,000 to $75,000 in daily fines, plus up to $10,000 per vehicle per day in some enforcement cases. Add in registration blocks that prevent you from legally operating, and you’re looking at lost revenue every day your truck sits instead of working.
The testing fee is a known, manageable business expense that keeps you legal and operational. It’s not optional and it’s not negotiable—it’s the cost of doing business in California with a heavy-duty diesel truck. Budget for it semi-annually right now, and quarterly starting in 2027 for newer trucks. Factor it into your operating costs the same way you do fuel, insurance, and maintenance, because skipping it puts everything else at risk.
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