Complete Guide to California's CARB Clean Truck Check Program
What Every Truck Owner Needs to Know in 2025
If you operate a diesel truck weighing over 14,000 lbs GVWR in California, the Clean Truck Check (CTC) isn't optional—it's the law. This comprehensive guide breaks down everything you need to know about staying compliant and avoiding costly penalties.
What is the Clean Truck Check?
The Clean Truck Check is California's mandatory inspection program for heavy-duty diesel vehicles. Implemented by the California Air Resources Board (CARB), this program ensures that emission control systems on diesel trucks are functioning properly. Think of it as an advanced smog check specifically designed for commercial vehicles.
Who Needs a Clean Truck Check?
Your vehicle requires a Clean Truck Check if it meets these criteria:
Diesel-powered
Gross Vehicle Weight Rating (GVWR) of 14,001 lbs or more
Operating in California (even if registered out-of-state)
Model year 2013 or newer (as of 2025)
This includes semi-trucks, box trucks, dump trucks, tow trucks, and many service vehicles. Even if you're just passing through California for deliveries, you're required to comply.
Testing Frequency and Deadlines
Vehicles must be tested twice per year, with inspections at least 90 days apart. The specific testing periods depend on your license plate's last digit:
Plates ending in 1-5: January 1 - June 30 and July 1 - December 31
Plates ending in 6-0: April 1 - September 30 and October 1 - March 31
Missing your testing window results in automatic non-compliance, potentially leading to DMV registration holds and DOT citations.
What Happens During the Test?
The inspection takes approximately 15-20 minutes and includes:
Connecting to your vehicle's OBD port
Running diagnostic scans of emission control systems
Checking for active fault codes
Verifying emission equipment functionality
Visual inspection of exhaust components
At NorCal CARB Mobile, we bring all necessary equipment directly to your location, eliminating downtime and keeping your trucks earning.
Consequences of Non-Compliance
Failing to maintain Clean Truck Check compliance can result in:
$1,000+ roadside citations
DMV registration blocks
DOT operating authority suspension
Inability to renew commercial insurance
Loss of contracts requiring CARB compliance
Mobile Testing Advantage
Why waste hours driving to a shop and waiting in line? Our mobile service means:
No lost revenue from truck downtime
Testing at your convenience
Fleet discounts starting at $50 per truck
Same-day compliance certificates
Direct submission to CARB database
Don't wait until it's too late. California enforcement is increasing, and the penalties aren't worth the risk. Schedule your mobile Clean Truck Check today and keep your business moving forward.
