Heavy-Duty Diesel Vehicle Enforcement

This page last reviewed July 24, 2019

The ARB's Heavy-Duty Vehicle Inspection Program and Periodic Smoke Inspection Program were adopted into law in 1988 (Senate Bill 1997) and 1990 (Senate Bill 2330), respectively to control excessive smoke emissions and tampering from heavy-duty diesel trucks and buses. The regulations, title 13 CCR, sections 2180-2189 for HDVIP, and title 13 CCR, sections 2190-2194 for PSIP, governing these programs were last amended in 2013.

new button Link to the new webpage on: Amendments to Smoke Inspection Programs and Development of Future, Comprehensive Heavy-Duty Vehicle Inspection and Maintenance Program.

Workshop Notices: Workshop Notice for February 28, 2017, Workshop Notice for May 17, 2017.

Announcement: New Opacity Standard Adopted in 2018 / New Training Required

In July 2018, the California Air Resources Board (CARB) approved amendments to the HDVIP and PSIP regulations, which require heavy-duty vehicles to meet a more stringent opacity limit of 5 percent opacity for most vehicles.  The new opacity limit goes into effect July 1, 2019.   


The new regulation requires persons who conduct PSIP opacity testing to obtain a CARB-approved smoke tester identification number.  To obtain this number, fleet owners or employees who conduct opacity tests on their own vehicles are required to take an online course, which will be offered at no cost through CARB’s website.  Non-fleet test operators who offer opacity test services to fleets are required to attend an in-person course (CCDET I or an equivalent course that has received CARB approval).  Current tester certificates will remain valid through the certificates expiration date.  All tests must adhere to the amended regulation requirements as of July 1, 2019.  In-person courses are currently available (http://ccdet.org/class-schedule/) and the online course will be available soon.  CARB will update this announcement when the online training becomes available.


For further information, please contact Tim Hartigan at Tim.Hartigan@arb.ca.gov or at (916) 229-0504.

Heavy-Duty Vehicle Inspection Program (HDVIP)

The HDVIP program requires heavy-duty trucks and buses to be inspected for excessive smoke and tampering, and engine certification label compliance. Any heavy-duty vehicle traveling in California, including vehicles registered in other states and foreign countries, may be tested. Tests are performed by ARB inspection teams at border crossings, CHP weigh stations, fleet facilities, and randomly selected roadside locations. Owners of trucks and buses found in violation are subject to minimum penalties starting at $300 per violation.

HDVIP Ports of Entry Video (wmv 111MB)

HDVIP Booklet May 2019 (pdf 249K)

Periodic Smoke Inspection Program (PSIP)

The PSIP program requires that diesel and bus fleet owners conduct annual smoke opacity inspections of their vehicles and repair those with excessive smoke emissions to ensure compliance. The ARB randomly audits fleets, maintenance and inspection records and tests a representative sample of vehicles. All vehicles that do not pass the test must be repaired and retested. A fleet owner that neglects to perform the annual smoke opacity inspection on applicable vehicles is subject to a penalty of $500.00 per vehicle, per year.

Beginning January 1, 2010, Assembly Bill 1488 (Mendoza) has required diesel vehicles (passenger cars and trucks) manufactured after model year 1997 with a gross vehicle weight rating (GVWR) of 14,000 pounds or less to be included in the California Smog Check Program.

PSIP Booklet May 2019 (pdf 249K)

Please review this Advisory for the latest information on smoke opacity testing:
Advisory 351: Enforcement of California's Periodic Smoke Inspection Program (PSIP)

Advisory 298: Smoke Testing Compliance Advisory

Emission Control Label (ECL)

Each vehicle operating in California - including those in transit from Mexico, Canada, or any other state - must be equipped with engines that meet California and/or U.S.EPA or equivalent emission standards. “Emission Control Label” or “ECL” means the label required by the “California Motor Vehicle Emission Control Label Specifications”, incorporated by reference in 13 CCR, section 1965, or Title 40, Code of Federal Regulations (CFR), Part 86, Subpart A.  The ECL must be legible, maintained at the location originally installed by the engine manufacturer and correspond to the engine serial number stamped on the engine.

Please see the Heavy-Duty Diesel Emission Control Label (ECL) Inspection Program web page for more information.

Advisory 364: On-Road In-Use Heavy-Duty Diesel Engine Labeling And Tampering
Advisory 354: Heavy Duty Diesel Vehicle & Engine Label Requirements

PSIP and ECL Compliance Tools

To assist in collecting and reporting PSIP and ECL information, the ARB Enforcement Division has provided an electronic audit table and "Statement of Facts" forms for your use. You may use these forms to complete your annual PSIP inspections.

Download the audit table (.xlsx) MS Excel 2010 Version

Download ECL "Statement of Facts" form (.pdf)

Download EIN "Statement of Facts" form (.pdf)

California Council on Diesel Education and Technology (CCDET) - CCDET Training Classes

Sign up for CCDET Training Classes at: http://ccdet.org/class-schedule/. CCDET provides training for fleet and other heavy duty diesel maintenance personnel, and to personnel of smoke testing services and facilities, by offering courses, through selected California community colleges, that provide an in-depth look at the ARB Heavy-Duty Vehicle Inspection Program (HDVIP), the Periodic Smoke Inspection Program (PSIP), and on Diesel Exhaust After-Treatment and Engine Maintenance. Fees for CCDET classes are $175.00 per class.

Notices sent to California-Based Heavy-Duty Vehicle Operators

Notices sent regarding Enforcement of the Fleet Periodic Smoke Inspection Program include:

Approved Engine Exemptions

The following is a listing of approved exempted heavy-duty engines pursuant to section 2182(b) of Title 13 California Code of Regulations: Engines Exempted to Higher Opacity Cutpoints.

Program Litigation

Smoke Meters List

A list of manufacturers and distributors of smoke opacity meters may be viewed at our Smoke Meter Manufacturers page. Please note that this posting does not constitute an endorsement or certification that this equipment complies with SAE J1667 specifications.

Smoke Test Standard SAE J1667

The snap acceleration smoke test procedure for heavy-duty vehicles from the Society of Automotive Engineers (SAE) is available at SAE J1667 (pdf 259K). The document may be viewed on screen, or downloaded and printed. Please read the copyright notice on the first page, regarding printing only a single (one) copy.

Smoke Opacity Testing Facilities

Please refer to "Diesel Fuel Injection Service" or "Truck Repairing and Service" in the yellow pages on SmartPages.com. Please see our current list of certified smoke testing facilities list.   Test facilities are now listed by their business address, but may provide services to multiple locations statewide. It should be noted that inclusion on the facilities list does not indicate ARB endorsement for any of the listed businesses; it indicates that the facilities hold a current CCDET certification and have requested to be listed on the ARB list.  It is the responsibility of the person who hires the service to verify that the procedures of SAE 1667 are followed. The list is not comprehensive: Not all businesses that hold a CCDET certification are listed. Please refer to the list requirements in our letter dated April 26, 2010. You may also contact Tim Bacon who maintains the Certified Smoke Opacity Testing Facilities list at (916) 229-0383.

Heavy-Duty Diesel Emission Control Strategy
Installation and Maintenance

Fleet owners may need to install a verified diesel emission control strategy to clean up emissions from older, dirtier diesel engines.  A diesel emission control strategy is a technology that, if maintained properly, reduces harmful air pollution from diesel engine exhaust before it is emitted into the air.  The most common technology used is a diesel particulate filter (DPF) that substitutes for the original factory muffler.  ARB evaluates and approves DPFs to meet specific particulate matter or nitrogen oxide emission reductions.


Contacts for the Heavy-Duty Vehicle Inspection Program

  • For Periodic Smoke Inspection Program (PSIP) information, please contact Tim Hartigan at Tim.Hartigan@arb.ca.gov or at (916) 229-0504.
  • For Heavy-Duty Vehicle Inspection Program (HDVIP) information, please contact Enforcement Division at
    (916) 322-7061;
  • For the Certified Smoke Opacity Testing Facilities List updates, please contact Tim Bacon at (916) 229-0383.