Heavy-Duty Certification Program
This page last reviewed November 24, 2015
The Heavy-Duty Certification Program is responsible for the certification of new incomplete or diesel-fueled medium-duty vehicles certified using the engine test procedure, heavy-duty engines, heavy-duty vehicles, and urban buses (UB). This page provides a collection of emission-related regulations, test procedures, Manufacturers Advisory Correspondences (MACs), Mailouts, and related documents applicable to these engines and vehicles, and is primarily for the interest and needs of manufacturers and others that are required to obtain certification from ARB. For public-oriented materials, please visit our On-Road Heavy-Duty Vehicle Program
A manufacturer wishing to certify an engine or vehicle must demonstrate that the emission control systems are durable, and that the exhaust emissions and evaporative emissions, as applicable, comply with the regulatory standards for the duration of the required useful life of the product. This demonstration is accomplished through durability and certification testing of the prototype certification engine(s) or vehicle(s). Compliance with on-board diagnostics, anti-tampering, fuel tank fill-pipe and openings, crankcase emissions, etc., as applicable, must be demonstrated also. An application for certification must be submitted to, and approved by, the Air Resources Board (ARB).
Production engines and vehicles must be identical in all material respects to the certification engine(s) and vehicle(s) for which the certification was granted. All emissions-related production running changes during production and field fixes must be approved. Production engines and vehicles must be properly labeled and the related emission control systems warranted for the warranty period specified by regulation. New and customer-owned production engines and vehicles are subject to compliance testing (by either the manufacturer or ARB) and warranty repairs reporting by the manufacturers, either of which can result in remedial actions.
Certification is granted only to the manufacturer of the engines and vehicles who controls the production specifications in order to ensure compliance of all production engines and vehicles. Certification can be granted to an importer only if the importer demonstrates that it has control of the production specifications. As an example, this demonstration can be effected by a contractual agreement between the original manufacturer and importer which gives the importer the sole authority to approve any changes to the specifications for production engines and vehicles. Importers lacking this control are subject to direct-import (a.k.a. gray-market) certification.
Manufacturers applying for certification for the first time must become registered with ARB. Please do the following:
- Letter of Intent: A physical letter which states the intent of the manufacturer to certify with ARB and presents an overview of what will be certified.
- Electronic Signatures Letter: A physical letter which includes the names and actual signatures of persons authorized to sign documents uploaded electronically to the Document Management System (DMS).
Please see MAC 2007-01 ( PDF - 88K ) for more information
- EPA Manufacturer Code: Manufacturers wishing to certify engines or evaporative families must register with EPA as a manufacturer and receive an EPA manufacturer code.
- Document Management System (DMS): Email a completed DMS users spreadsheet ( XLS - 59K ), which lists the persons to be granted access to the online DMS, to Kimberly Pryor, Section Manager, or James Pang of the Compression-Ignition and Heavy-Duty Certification Section. More information about ARB's DMS is available online on the OpenDMS webpage.
- Letter of Authorization: A physical letter on the manufacturer's letterhead which authorizes specific consultant(s) to communicate with ARB on the manufacturer's behalf
When these items are completed, a staff engineer will be assigned to act as the primary contact with the manufacturer, including coordinating meetings, reviewing applications, and answering questions.
Manufacturers who have registered previously must notify ARB whenever there are any changes in the preceding items.
For engine certification ARB requires a PDF printout of the 'On-highway Engine' FileMaker Pro templates created by EPA. These templates are available on the EPA website
For evaporative certification ARB encourages use of the "Large Engine Evaporative Emission Form" template given by EPA in the document "EPA Large Engine and Evaporative Certification Guidance", Appendix E1 ( PDF - 3580K
For additional certification guidance please review the EPA document EPA420-B-98-002, "Certification Guidance for Engines Regulated Under: 40 CFR Part 86 (On-Highway Heavy-Duty Engines) and 40 CFR Part 89 (Nonroad CI Engines)" ( PDF - 311K
ARB is currently developing an electronic application submission system which will replace application paper submissions. For more information, please visit the E-Cert
The regulations applicable to an application for certification depend on the engines or vehicles the manufacturer intends to certify, therefore, it is important that a manufacturer be familiar with the various regulations which may apply to their intended products; the most common regulations are listed below to promote this. Also, the Compression Ignition and Heavy-Duty (CIHD) Certification Checklist ( PDF - 32K
) may be used as a list of what information may be required. ARB encourages manufacturers to annually present an overview, in a meeting or via conference call, what specific products they intend to certify during the model year. These "Certification Preview" meetings allow ARB to give specific feedback and regulatory guidance to manufacturers in a timely manner.
When an application is submitted to DMS, the assigned engineer will do a preliminary review of the material submitted and within 30 days will notify the manufacturer whether there is sufficient information to conduct a full review. If a full review is warranted, then the engineer will review the application and will, within another 30 days, either respond with substantive feedback or submit the application for review by peers and management prior to the Executive Order being signed. These timeframes are the outside limits ARB holds itself to, and experience has shown that nearly all applications are successfully processed is much less time. ARB encourages manufacturers to be responsive to any requests for additional information, additional test data, clarifications, etc. so that applications may be processed in a timely manner. Failure to respond to ARB requests will eventually lead to warnings, and ultimately, rejection of the application.
Please address all communication to the Division Chief of the Emissions Compliance, Automotive Regulations and Science Division. The proper mailing address is:
Emissions Compliance, Automotive Regulations and Science Division
9480 Telstar Avenue, Suite 4
El Monte, CA 91731
Regulations, Test Procedures, and Policies
California's emission standards for heavy-duty engines and vehicles are contained in California Code of Regulations, Title 13, and the following test procedures, as incorporated by reference. Section numbers of selected topics are listed for your convenience when performing a search on the regulations web page.
Medium-Duty Vehicles (incomplete or diesel of 8501-14000 pound GVWR certified under engine test procedure):
13 CCR §1961. Exhaust Emission Standards and Test Procedures - 2004 and Subsequent Model Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles.
"California Exhaust Emission Standards and Test Procedures for 2001 and Subsequent Model Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles", as amended on September 27, 2010 ( PDF - 609K
Heavy-Duty Engines and Vehicles:
13 CCR § 1956.8. Exhaust Emissions Standards and Test Procedures -1985 and Subsequent Model Heavy-Duty Engines and Vehicles.
Heavy-Duty Otto-Cycle Engines and Vehicles:
Heavy-Duty Diesel Engines and Vehicles:
"California Exhaust Emission Standards and Test Procedures for 1987 through 2003 Model Heavy-Duty Otto-Cycle Engines and Vehicles", as amended on December 27, 2000 ( PDF -86K
"California Exhaust Emission Standards and Test Procedures for 2004 and Subsequent Model Heavy-Duty Otto-Cycle Engines", adopted December 27, 2000, as amended on October 21, 2014 (PDF - 251K
"California Exhaust Emission Standards and Test Procedures for 1985 through 2003 Model Heavy-Duty Diesel Engines and Vehicles", amended on December 12, 2002 ( PDF - 102K
"California Exhaust Emission Standards and Test Procedures for 2004 and Subsequent Model Heavy-Duty Diesel Engines and Vehicles", adopted December 12, 2000, as amended on October 21, 2014 ( PDF - 577K
13 CCR § 1956.1. Exhaust Emission Standards and Test Procedures - 1985 Through 2006 Model-Year Heavy-Duty Urban Bus Engines and Vehicles.
Heavy-Duty Hybrid Electric Vehicles:
Please visit the Heavy-Duty Hybrid Electric Vehicle Certification Procedures
webpage for more detailed information. All heavy-duty hybrids must comply with the OBD regulations in order to be certified; contact the OBD section for more information.
"California Interim Certification Procedures for 2004 and Subsequent Model Hybrid-Electric and Other Hybrid Vehicles in the Urban Bus and Heavy-Duty Vehicle Classes", adopted October 24, 2002, as amended on October 21, 2014 ( PDF - 217K
Heavy-Duty Electric Vehicles and Non-Combustion Hybrid Vehicles: View Issued Heavy-Duty Approvals
California regulations for heavy-duty zero-emission vehicles are still in the development process. During the interim, manufacturers may sell heavy-duty electric vehicles and non-combustion hybrid vehicles in California without an Executive Order. Seperate programs within ARB or external agencies, however, may require confirmation that the vehicles are correctly identified as heavy-duty electric vehicles or non-combustion hybrid vehicles. Consequently, manufacturers may request an Approval letter which states that ARB confirms that the vehicle manufacturer has correctly identified those vehicles as heavy-duty electric vehicles or non-combustion hybrid vehicles. Manufacturers must submit the information requested in the document "Information Required for Review of Requests for Approvals of Heavy-Duty Electric Vehicles and Non-Combustion Hybrid Vehicles" ( PDF - 85K
) in order for ARB to verify that the vehicles do not utilize combustion and do not emit any exhaust emissions or fuel-based evaporative emissions. A list of Approval letters issued is posted on the Heavy-Duty Approvals
webpage. These approvals are valid for new vehicles only. Manufacturers wishing to convert vehicles previously certified must follow ARB's Engine Change Policy
. Contact by email Tony Martino
, Section Manager, of the Aftermarket Parts section for more information.
Fuel-Fired Heaters: View Issued Fuel-Fired Heater Approvals
California regulations require that Fuel-Fired Heaters comply with the Heavy-Duty Diesel Engine Idling Requirements in 13 CCR 1956.8(a)(6)(D) and the Airborne Toxic Control Measure to Limit Diesel-Fueled Commercial Motor Vehicle Idling in 13 CCR 2485(c)(3)(B). Approval letters are issued for Fuel-Fired Heaters which comply with these requirements. A list of Approval letters issued is posted on the Heavy-Duty Approvals
13 CCR §1976. Standards and Test Procedures for Motor Vehicle Fuel Evaporative Emissions.
“California Evaporative Emission Standards and Test Procedures for 2001 and Subsequent Model Motor Vehicles,”
adopted August 5, 1999, last amended December 6, 2012. (
PDF - 837K
Emission Control Warranty:
13 CCR § 2035-2041, 2044.
Vehicle Emission Labeling:
13 CCR § 1965. Emission Control, Smog Index, and Environmental Performance Labels - 1979 and Subsequent Model-Year Motor Vehicles.
"California Motor Vehicle Emission Control and Smog Index Label Specifications for 1978 through 2003 Model Year Model Year Motorcycles, Light-, Medium-, and Heavy-Duty Engines and Vehicles.", as amended on September 5, 2003. ( PDF - 84K
EPA Document CISD-2006-19, "New Examples of Vehicle Emission Control Information (VECI) Labels and Heavy-Duty Engine Labels" ( PDF - 153K
Fill Pipes and Openings for Vehicle Fuel Tanks:
13 CCR § 2235. Specifications for Fill Pipes and Openings of Motor Vehicle Fuel Tanks.
"Specifications for Fill Pipes and Openings of Motor Vehicle Fuel Tanks.", adopted March 19, 1976, last amended January 22, 1990.( PDF - 642K
"Specifications For Fill Pipes And Openings Of 2015 And Subsequent Model Motor Vehicle Fuel Tanks.", adopted March 22, 2012.( PDF - 69K
Engine Family and Evaporative Family Naming:
EPA document EPA420-B-98-002, "Certification Guidance for Engines Regulated Under: 40 CFR Part 86 (On-Highway Heavy-Duty Engines) and 40 CFR Part 89 (Nonroad CI Engines)", Appendix D ( PDF - 311K
EPA document CISD-07-03, "EPA Standardized Naming Conventions for Model Year 2009 and Later Engine Family and Test Group Names, Evaporative/Refueling Family Names, and Permeation Family Names" ( PDF - 110K
EPA document CD-12-01, "EPA Standardized Naming Conventions for Model Year 2013 and Later Heavy-Duty Highway Vehicle Family Names" ( PDF - 194K
Assigned Deterioration Factors:
EPA document CCD-00-12, "REISSUE OF ASSIGNED DF'S FOR GASEOUS-FUELED VEHICLES AND ENGINES, formerly CD-95-14" ( PDF - 2097K
EPA document CCD-05-10, "Assigned Deterioration Factors" ( PDF - 512K
EPA document CD-12-07, "Assigned Deterioration Factors" ( PDF - 37K
Manufacturers Advisory Correspondence:
MAC 99-04: Tamper-Resistance Requirements for Diesel Injection Pumps( PDF - 406K
MAC 07-01: Policy regarding the use of Electronic Signatures in the Air Resources Board’s (ARB) Document Management System for Certification ( PDF - 88K
MAC 07-03: Protocol for the Engine Shutdown System on New California Certified Heavy-Duty Diesel Engines for 2008 and Subsequent Model Years ( PDF - 101K
MSO 2007-03: New Requirement to Report Carbon Dioxide Emissions from 2008 and Subsequent Model Year California Certified Vehicles and Engines ( PDF - 85K
MSO 2012-02: Public Workshop to Discuss Current Alternative Fuel Conversion Requirements for New and Used Vehicles and Engines.
(PDF - 47K
ARB Heavy-Duty Vehicle SCR Technology Field Evaluation
ARB Heavy-Duty Vehicle SCR Technology Field Evaluation-Second Study
The California Air Resources Board (ARB) staff conducted field investigations into the implementation of 2010 model year (MY) on-road heavy-duty diesel (HDD) engines equipped with Selective Catalytic Reduction (SCR). The investigations included: (1) two surveys of diesel exhaust fluid (DEF) availability within the State of California, (2) a survey to determine whether truck operators driving 2010 MY SCR-equipped trucks on California roadways have tampered with SCR components or are not using DEF, (3) an examination of the types and effectiveness of SCR driver inducements employed on 2010 MY HDD vehicles, and (4) an examination of the emission impacts of HDD SCR-equipped vehicles when DEF has been depleted, diluted or the SCR system has been tampered with. All questions regarding this report should be directed to Ms. Annette Hebert
, Chief, Mobile Source Operations Division, at (626) 450-6150.
SCR Technology Field Evaluation Report ( PDF - 856K
The California Air Resources Board (ARB) staff conducted a second field study in 2011/2012 similar to the first study but with new heavy-duty diesel (HDD) engines tested. The investigations included (1) a follow-up survey of diesel exhaust fluid (DEF) availability with the State of California, (2) roadside inspections to determine whether truck operators driving Selective Catalyst Reduction (SCR) equipped trucks on California roadways have tampered with SCR components or are not using DEF, (3) a re-evaluation of driver inducements on two SCR-equipped 2010 model year (MY) Cummins engines evaluated in the first study where error in programming and part malfunctions were found, (4) a continued evaluation of 2010+ MY NOx control strategies including an examination of the types and effectiveness of SCR driver inducements employed on SCR-equipped trucks, and (5) an examination of the emission impacts of HDD vehicles. All questions regarding this report should be directed to Mr. Tom Valencia
, Manager, In-Use Compliance Section, Mobile Source Operations Division, (626) 575-6741.
SCR Technology Field Evaluation - Second Report ( PDF - 6930K
Workshops / Meetings
Public Workshop to Discuss Current Alternative Fuel Conversion Requirements for New and Used Vehicles and Engines
Selective Catalytic Reduction Workshop for New Diesel Engines
The California Air Resources Board (ARB) staff hosted a public workshop to clarify ARB's current requirements regarding conversion of vehicles and engines to operate on alternative fuels. The United States Environmental Protection Agency (U.S. EPA) promulgated changes to its rules affecting alternative fuel converters in 2011, and since then ARB has received numerous inquiries regarding its requirements for conversion of vehicles and engines to alternative fuels. Manufacturers have requested guidance on how to certify and show compliance with the ARB regulations. The intent of the workshop was to clarify ARB's regulations and test procedures regarding conversion of vehicles and engines to operate on alternative fuels for new vehicles and engines and for vehicles and engines that have already been purchased (aftermarket).
For more information, please read mail-out MSO #2012-02 ( PDF - 47K
Durability Demonstration Workshop for New Diesel Engines
The California Air Resources Board (ARB) held a workshop concerning selective catalytic reduction for new diesel engines on July 20, 2010.
The California Air Resources Board (ARB) held a workshop concerning durability demonstration and deterioration factors for new diesel engines on March 24, 2010.
This portion is still under development; check back soon!
Please sign up to the Mobile Source Mailouts and MAC list server.
Air Resources Board document management system, OpenDMS