On-Board Diagnostics (OBD) Program
This page last reviewed August 8, 2016.
On-Board Diagnostic systems are self-diagnostic systems incorporated into the computers of new vehicles. Nearly 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:
August 8, 2016: "Clean" versions of the OBD II and HD OBD final regulation orders have been made available on the OBD II Regulations and Rulemaking page and the Heavy-Duty OBD Regulations and Rulemaking page. Additionally, the electronic templates for the OBD II gasoline and diesel monitor checklists (which are part of ARB Mail-Out #MSC 06-23) have been updated to reflect the Final Regulation Orders and are available on the OBD Updates page.
July 27, 2016: The Final Rulemaking package (Final Statement of Reasons, Final Regulation Orders), approved by the Office of Administrative Law on July 25, 2016, have been made available on the OBD II Regulations and Rulemaking page.
March 21, 2016: The 15-day notice package (Notice, Modified Regulatory Text) for the OBD II rulemaking update (Board Hearing date: September 24-25, 2015) made available on 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.
Innovative Technology Regulation: Link to ARB's ongoing regulatory work regarding certification (including OBD certification) and aftermarket part approval flexibility for "innovative" medium- and heavy-duty engine and vehicle technologies.
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.