On-Board Diagnostics (OBD) Program
This page last reviewed October 29, 2014.
On-Board Diagnostic 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.
Below are links to further information regarding OBD, including the latest regulations and reports.
Most Recent Updates:
October 29, 2014: The notice and ARB presentation for the October 30, 2014 OBD II workshop have been made available on the OBD Workshops and Meetings page.
May 19, 2014: Updated rate-based data report templates for OBD II gasoline and diesel vehicles have been made available on the OBD Updates page.
October 14, 2013: 2012 and 2013 ARB SAE OBD Symposium presentations have been made available on the OBD Updates page.
August 30, 2013: "Clean" versions of the HD OBD and OBD II final regulation orders have been made available on the Heavy-Duty OBD Regulations and Rulemaking page and the OBD II Regulations and Rulemaking page.
Consumer Information on OBD II:
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:
Past OBD II Regulatory Documents: Links to past regulations and rulemaking activities.
Heavy-Duty OBD Regulations and Rulemaking Information:
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 Workshops and Meetings: Links to all OBD-related workshops/meetings information.
Weber State Clearinghouse: Website containing information aimed at helping technicians (I/M and repair technicians) address problem vehicles.
OBD II-I/M Program Information:
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:
For more information, please contact Mike Regenfuss at (626) 575-7004.