On-Board Diagnostics Program

This page last reviewed May 2, 2008

 

Background:

On-Board Diagnostic (OBD) systems are self-diagnostic systems incorporated into the computers of new vehicles. All 1996 and newer vehicles less than 14,000 lbs. (e.g., passenger cars, pickup trucks, sport utility vehicles) are equipped with OBD II systems, which are California's second generation of OBD requirements. The OBD II system monitors virtually every component that can affect the emission performance of the vehicle to ensure that the vehicle remains as clean as possible over its entire life, and assists repair technicians in diagnosing and fixing problems with the computerized engine controls. If a problem is detected, the OBD II system illuminates a warning lamp on the vehicle instrument panel to alert the driver. This warning lamp typically contains the phrase Check Engine or Service Engine Soon (see below). The system will also store important information about the detected malfunction so that a repair technician can accurately find and fix the problem. ARB has recently developed similar OBD requirements for heavy-duty vehicles over 14,000 lbs.

Check Engine Lights

Below are links to further information regarding OBD, including the latest regulations and reports.


Most Recent Updates:

February 4, 2008: The websites have been updated with a left-hand column that includes all important and relevant links.  Additionally, updates have been made to the Facts Sheet, including more information on addressing vehicles that fail Smog Check due to incomplete readiness flags, and an electronic version of ARB Mail-Out #95-20 has been made available in the OBD Updates page.

November 16, 2007:  The final, OAL-approved OBD II and emission warranty regulations added to the "OBD II Regulations and Rulemaking" page.  Please use these versions of the regulations as the definitive finalized versions, as they contain differences from the previously available versions of the regulations, which we have detailed.


Consumer Information on OBD II:

    Facts Sheet: Frequently asked questions (FAQs) about OBD II and how it works.

    U.S. EPA OBD II site: The United States Environmental Protection Agency's (U.S. EPA) website also includes consumer information about the OBD II system.

OBD II Regulations and Rulemaking Information:

Heavy-Duty OBD Regulations and Rulemaking Information:

    In 2004, ARB adopted a regulation requiring diagnostic systems on all 2007 and subsequent model year heavy-duty engines and vehicles (i.e., vehicles with a gross vehicle weight rating greater than 14,000 lbs.) in California. ARB recently adopted a comprehensive OBD regulation for 2010 and subsequent model year heavy-duty vehicles.

    Heavy Duty OBD Regulations and Rulemaking: Links to the ARB's current rulemaking activities, including draft regulations and staff reports.

    U.S. EPA Heavy Duty OBD Site: U.S. EPA's website containing its heavy-duty requirements and other information.

Other OBD Information:

OBD Updates: Links to other OBD-related information, including Mail-Outs and ARB presentations from conferences.

OBD II-I/M Program Information:

    ARB has worked with U.S. EPA to develop national guidelines for the implementation of OBD II into the Inspection and Maintenance (I/M) program. ARB has also worked with the Bureau of Automotive Repair (BAR), which is part of the California Department of Consumer Affairs, in its incorporation of OBD II into the California Smog Check program, which is administered by BAR.

    U.S. EPA OBD II-I/M Site: U.S. EPA website containing the latest reports and information on the incorporation of OBD II into the I/M program.

    BAR Smog Check Site: BAR's Smog Check website containing details regarding the use of OBD II in its Smog Check program.

E-Mail Updates for OBD:

    OBD List Serve: Sign up here for e-mail updates regarding ARB's activities concerning OBD.


WHERE CAN I GET MORE INFORMATION?

For more information, please call Mike McCarthy at (626) 771-3614 or via e-mail at mmccarth@arb.ca.gov.


 
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