How to Stay CARB Compliant with Clean Truck Check: A Complete Guide for Fleets
- David Briscoe
- Oct 7
- 4 min read
Updated: Oct 7
Introduction
In an era of increasing environmental regulation, California’s CARB Compliant Clean Truck Check (aka HD I/M) program stands as a key regulatory requirement for heavy-duty truck operators. If your fleet includes diesel, alternative fuel, or hybrid vehicles over 14,000 lbs (GVWR) that operate on California roads, staying CARB compliant is not optional. With DMV registration holds, fines, and operational delays on the line, you need a clear roadmap. This guide explains what Clean Truck Check means, who’s affected, how to comply, common pitfalls, and best practices to remain compliant year after year.
What Is CARB Clean Truck Check?
The Clean Truck Check program, also called Heavy-Duty Inspection & Maintenance (HD I/M), is a CARB initiative to ensure that heavy-duty vehicles maintain their emissions control systems in working order over time.
The goal: reduce truck emissions, detect high emitters, and promote fleet maintenance
Who Must Comply With CARB Compliant Clean Truck Check & Which Vehicles Are Exempt?
Which Vehicles Are Subject to Clean Truck Check?
If your vehicle meets all of the following, it's likely subject:
Gross Vehicle Weight Rating (GVWR) over 14,000 lbs
Powered by diesel or alternative fuel (non-gasoline / not zero emission)
Operates on California public roads, even if registered out of state
Affected vehicle types include commercial trucks, buses, hybrid trucks, government vehicles, motorhomes (if registered in CA) etc.
Exemptions: Who Is Not Covered?
Some vehicles are exempt, including:
Zero-emission vehicles
Authorized emergency vehicles (meeting specific definitions)
Military tactical vehicles
Motorhomes registered outside California
Historical vehicles
Vehicles under experimental permits
New engines meeting very strict NOx standards
Note: If your vehicle is exempt, it may not need to be reported, but you should verify exemptions carefully to avoid misclassification.
Steps to Achieve CARB Compliance for Clean Truck Check
Here’s a sequential roadmap to stay compliant:
1. Register in the CTC-VIS System
Create an account in CTC-VIS (Clean Truck Check Vehicle Inspection System).
Report your entity/fleet and vehicle details (VIN, registration, make/model, weight class).
Ensure the VIN reported matches DMV records, to avoid registration holds.
2. Pay the Annual Compliance Fee
Each vehicle pays a compliance fee (starting at ~$30, adjusted annually).
Payment must be via CTC-VIS. Other CARB portals might not be accepted.
After payment, the compliance certificate is generated (1–2 business days for credit/debit, ~7 days for eCheck).
3. Determine Testing Type & Deadline
Based on the model year / engine type, vehicles may be OBD-equipped or non-OBD.
OBD vehicles (e.g. diesel engines 2013+ or certain alt-fuel engines) require a scan via a CARB-certified OBD test device.
Non-OBD vehicles require a smoke opacity test plus a visual inspection of emissions controls.
Testing must be done by CARB credentialed testers (who’ve passed CARB’s online training + exam with ≥80%)
You may test up to 90 days prior to the compliance deadline to allow for repairs.
Semi-annual testing is required for many vehicles; from 2027, OBD vehicles may require quarterly tests.
4. Submit Passing Test Results
Upon a passing compliance test, the tester submits results via CTC-VIS, updating the certificate.
Once all compliance conditions are met, your compliance certificate is available for download.
DMV will update the status (often 1–3 business days) so registration holds are lifted
What If a Vehicle Fails?
Failure, “Not Ready”, or “Invalid Test” results are not considered compliant.
If a vehicle fails, perform repairs (e.g. emissions control system, sensors, injectors).
For OBD “Not Ready” results, you may need to further drive the vehicle to meet OBD readiness criteria before retesting.
Always retest and submit a passing test before your deadline to avoid non‐compliance consequences.
Also note that remote emissions monitoring / high emitter screening (e.g. via roadside devices) can trigger a Notice to Submit to Testing (NST), even if your last test passed. In that case, you have 30 days to submit a passing test.
Consequences of Non-Compliance
Failing to comply with Clean Truck Check can lead to:
DMV registration holds, blocking your ability to legally operate on public roads
Civil penalties / fines (varying amounts)
Denied access to freight facilities or railyards in some cases, for non-compliant vehicles
Loss of reputation, downtime, repair costs, administrative burden
Given the risks, compliance is critical, not optional.
Best Practices & Pro Tips
Plan ahead — don’t wait until the compliance deadline; test early (within the 90-day window).
Maintain emissions systems proactively: sensors, DPFs, EGR valves, SCR systems, etc.
Use credentialed testers you trust — avoid delays or errors in submission.
Monitor reminders and alerts via CTC-VIS; CARB sends email summaries for upcoming deadlines.
Keep detailed maintenance logs to support test results and compliance.
Train internal staff on reg changes; CARB changes implementation phases (e.g. quarterly testing for OBD after 2027)
Watch for new rulings or exemptions (e.g. ZEV purchase exemptions for certain body types) under related CARB programs.
Stay informed via CARB’s TruckStop resources, webinars, and documentation.
Frequently Asked Questions (FAQ)
Q: When did compliance begin?
Clean Truck Check regulatory testing took effect October 1, 2024, and all deadlines on or after January 1, 2025 require passing emissions tests.
Q: How often must I test? Most subject vehicles will test two times per year (semi-annual).
Starting 2027, OBD-equipped vehicles might require quarterly tests.
Q: Can I test early? Yes — tests may be submitted up to 90 days before the compliance due date.
Q: What if I receive a Notice to Submit to Testing (NST)?You must submit a passing emissions test within 30 days of the NST.
Q: Are there low-use or small-fleet exemptions? No. The Clean Truck Check program does not include a low-use exemption, and there is no small fleet carve-out. rvia.org
Q: How long until DMV registration holds are lifted? Once compliance is achieved and certificate is downloaded, DMV holds are usually cleared within 1–3 business days.
Conclusion
Meeting CARB compliance through the Clean Truck Check program is a significant but manageable component of fleet operations in California. By understanding the rules, starting early, maintaining equipment, and staying organized with CTC-VIS, you can avoid costly penalties and downtime while helping to reduce emissions. The benefits go beyond compliance — a well-maintained fleet is more fuel efficient, reliable, and aligned with environmental goals.
If you'd like help customizing a compliance roadmap for your fleet, or need assistance with implementation (e.g. credentialed tester selection, training, recordkeeping), I’d be happy to help further.
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