OBD II Regulations and Rulemaking

This page last reviewed January 7, 2013.

Clean Versions of the Latest OAL-Approved OBD II Regulations

Here you will find the "clean" versions (with no strike-outs or underlines) of the OBD II and associated enforcement regulations, sections 1968.2 and 1968.5, title 13, California Code of Regulations.  Please also note that the official regulations can be found at Barclays Official California Code of Regulations and at OAL.

Note: The regulations above include amendments proposed with the Low Emission Vehicle III (LEV III) and Greenhouse Gas (GHG) rulemaking package at the January 26-27, 2012 Board Hearing and approved by OAL on August 7, 2012.  The regulatory documents related to this rulemaking can be found on the LEV III and GHG regulatory website.  For reference, details of these OBD II amendments (with strike-outs and underlines) can be found on pages 118-135 of the Final Regulation Order (PDF - 843K).

  • Past OAL-approved OBD II regulations versions

Documents for the Heavy-Duty OBD and OBD II 15-Day Notice: posted January 4, 2013

ARB staff has recently published documents that detail modifications made to the staff's original proposed amendments to the OBD II and heavy-duty OBD regulations and associated OBD enforcement regulations, sections 1968.2, 1968.5, 1971.1, and 1971.5 of title 13, California Code of Regulations (Board Hearing date: August 23, 2012). Deadline for public comment on the changes: Friday, January 25, 2013. You can find the regulatory documents pertaining to the 15-day notice on the Heavy-Duty OBD webpage. 

Documents for the Board Hearing: August 23, 2012 (posted July 9, 2012)

ARB will hold a Board Hearing on August 23, 2012 to consider adoption of staff's proposed amendments to the OBD II and heavy-duty OBD regulations and associated OBD enforcement regulations (sections 1968.2, 1968.5, 1971.1, and 1971.5 of title 13, California Code of Regulations). The majority of the OBD II proposed changes are intended to make the requirements for medium-duty diesel vehicles be consistent with those changes being proposed for heavy-duty diesel engines in the heavy-duty OBD regulation.  You can find the regulatory documents pertaining to the Board Hearing on the Heavy-Duty OBD webpage.

Documents for the OBD Final Statement of Reasons package:  May 19, 2010

The Office of Administrative Law recently approved the final rulemaking package for the OBD II and HD OBD regulations (Board Hearing date: May 28, 2009) on May 18, 2010.  These documents include the Final Statement of Reasons and the Final Regulation Orders for the OBD II regulation, the HD OBD regulation, and the HD OBD enforcement regulation.  You can find the regulatory documents pertaining to the final rulemaking package on the Heavy-Duty OBD webpage.


Documents for the OBD 15-Day Notice: October 20, 2009

ARB staff has recently published documents that detail modifications made to the staff's original proposed amendments to the OBD II and heavy-duty OBD regulations (Board Hearing date: May 28, 2009). Deadline for public comment on the changes: Friday, November 13, 2009. You can find the regulatory documents pertaining to the 15-day notice on the Heavy-Duty OBD webpage.

Documents for the Board Hearing: May 28, 2009

ARB will hold a Board Hearing on May 28, 2009, to propose amendments to the OBD II and heavy-duty OBD regulations (sections 1968.2 and 1971.1 of title 13, California Code of Regulations) for adoption. The majority of the OBD II proposed changes are intended to be consistent with those changes being proposed for heavy-duty diesel engines in the heavy-duty OBD regulation.  You can find the regulatory documents pertaining to the Board Hearing on the Heavy-Duty OBD webpage.

Clean Versions of the OAL-approved Final Regulation Orders for OBD II and Emission Warranty Regulations

Here you will find the "clean" versions (with no strike-outs or underlines) of the final regulation orders that were approved on November 9, 2007, for the OBD II and emission warranty regulations, sections 1968.2, 1968.5, 2035, 2037, and 2038, title 13, California Code of Regulations.

OAL-Approved Final Regulation Order for OBD II and Emission Warranty Regulations: approved on November 9, 2007

Here you will find the final regulation orders for the OBD II and emission warranty regulations, sections 1968.2, 1968.5, 2035, 2037, and 2038, title 13, California Code of Regulations, approved by the Office of Administrative Law on November 9, 2007. These versions of the regulations include the "track changes" format to identify changes from the original regulation (additions are indicated by underline while deletions are indicated by strikeout).  Regarding sections 1968.5, 2035, 2037, and 2038, no noteable changes were made between the OAL-approved regulation orders and the versions submitted on August 10, 2007.  However, regarding section 1968.2, the OAL-approved regulation order has a few noteable differences (in addition to minor formatting changes) from the regulation order provided earlier (the August 10, 2007 version), which are as follows:

Section 1968.2(c): The definitions of "Supplemental Emission Test (SET) cycle" and "US06 cycle" were amended to include the phrase "as amended July 13, 2005."

Section 1968.2 (g)(1): The additional language (made available with the 1st 15-Day Notice) that allowed manufacturers to use a subsequently revised version of any of the SAE and ISO documents referenced in the regulation has been removed.  OAL has determined that the inclusion of this language was not appropriate, and that subsequently revised versions of these documents should be directly referenced in future amendments to the regulations.

Section 1968.2(g)(1.10): The date of the reference for the SAE J1939 document has been corrected from March 2005 to January 2005. This should not cause any problems, since the March 2005 version of this document doesn't exist, and the January 2005 version is incorporated in SAE HS-1939, which is also referenced in section 1968.2(g)(1.10).

Section 1968.2 (g)(4.7.4): The change to the CAL ID and CVN requirement model year start date from 2005 to 2008 (made available with the 1st 15-Day Notice) was accidentally left out, so it has been corrected to 2008 in this final version.  Additionally, the language that references October 25, 2007 as the submittal date of the first set of CAL ID and CVN information (made available with the 1st 15-Day Notice) has been deleted since that specific date has passed.

Section 1968.2(k): No new substantive changes were made to this section, but there are differences in how the amendments are presented from the previous regulation versions with tracked changes. The previous versions indicated both additions and deletions from the original language in section (k) "Deficiencies." However, since the section was originally in section (i) and moved to a new section (k) in the Board Hearing version, all amendments to this section as well as the original language should have been designated as "additions" (i.e., all the language under (k) should have been underlined), so no deletions from the original language (i.e., none of the strike-out language present in the previous versions) would have been specifically shown in the language even though deletions have indeed been made. Despite these cosmetic changes, the final requirements are still the same.

  • Section 1968.2: ( PDF - 717K )
  • Section 1968.5: ( PDF - 142K )
  • Sections 2035, 2037, and 2038: ( PDF - 68K )
  • Memo to OAL (dated October 17, 2007): This memo includes details on OAL's reasons for not approving the rulemaking package submitted on August 10, 2007, and also ARB's request for an expeditious review and early effective date for the resubmitted regulation orders above. The regulation orders were subsequently approved by OAL on November 9, 2007. ( PDF - 18K )

Previously Released Unofficial Final Regulation Orders for OBD II and Emission Warranty Regulations submitted on August 10, 2007: not OAL-approved


Here you will find the final regulation orders that were submitted to the Office of Administrative Law on August 10, 2007, for the OBD II and emission warranty regulations, sections 1968.2, 1968.5, 2035, 2037, and 2038, title 13, California Code of Regulations. Please note that these versions of the regulations were not approved by the Office of Administrative Law on September 24, 2007, due to reasons stated in the Memo to OAL (dated October 17, 2007) available above.


Other Documents in the Final Statement of Reasons package for the OBD II and Emission Warranty rulemaking

Here you will find the documents that are part of the final rulemaking package for the OBD II and emission warranty regulations that was filed with the Office of Administrative Law on August 10, 2007.

  • Final Statement of Reasons:Summary of the adopted changes to the regulations and each objection and recommendation made by the public during the 45-Day and 15-Day comment periods. ( PDF - 355K )
  • Updated Informative Digest: Summary of the amendments to the regulations and the rulemaking process. ( PDF - 31K )

Documents for the 2nd OBD II 15-Day Notice: July 23, 2007

Here you will find the documents that detail the second set of modifications made to the staff's original proposed amendments to the OBD II regulations. Deadline for public comment on the changes: Tuesday, August 7, 2007.

  • Second Notice of Public Availability of Modified Text: The 2nd 15-Day Notice summarizing the changes to the regulations. The notice includes a summary of the Board's action, a list of the second set of additional changes made to the original proposed amendments to the regulations, availability information of the attachment, and relevant dates. ( PDF - 26K )
  • Attachment I: Modified text of OBD II regulations: This document includes the highlighted double strikeout/underline format to identify the second set of additional changes to the original proposed amendments to the regulations made available to the public prior to the Board Hearing. ( PDF - 59K )


Documents for the 1st OBD II 15-Day Notice: May 22, 2007

Here you will find the documents that detail the modifications made to the staff's original proposed amendments to the OBD II regulations, including changes made since the September 2006 Board Hearing (i.e., after the "Staff's Suggested Modifications to Proposed Regulations" available below). Deadline for public comment on the changes: Tuesday, June 19, 2007.

  • Notice of Public Availability of Modified Text: The 15-Day Notice summarizing the changes to the regulation. The notice includes a summary of the Board's action, a list of the additional changes made to the original proposed amendments to the regulation, availability information of the attachments, and relevant dates. ( PDF - 17K )
  • Attachment I: Resolution 06-26 (adopted at hearing): Resolution by the Board on 9/28/06 adopting the modifications to the regulation. ( PDF - 45K )
    • Attachment A : Proposed amendments to section 1968.2: Available below.
    • Attachment B: Proposed amendments to section 1968.5: Available below.
    • Attachment C: Proposed amendments to sections 2035, 2037, and 2038: Available below.
    • Attachment D: Staff's suggested modifications to proposed regulations: Available below.
  • Attachment II: Modified Text of the OBD II Regulations: This document includes the double strikeout/underline format to identify additional changes to the original proposed amendments to the regulations made available to the public prior to the Board Hearing. ( PDF - 146K )

ARB Mailout MSC #06-23: Dated December 21, 2006

ARB Mailout MSC #06-23, "Guidelines for On-Board Diagnostic II (OBD II) Certification Data," and its associated electronic templates can be found on the "OBD Updates" page here .


Documents for the Board Hearing: September 28, 2006

ARB held a Board Hearing on September 28, 2006, to propose amendments to the OBD II and emission warranty regulations for adoption. Here you will find the ARB presentation and the regulatory documents pertaining to the Board Hearing:

  • Board Hearing Presentation: ARB board hearing presentation of the proposed changes to the regulations.
  • Staff's Suggested Modifications to Proposed Regulations: ARB's changes to the proposed regulations (section 1968.2 and 1968.5) since its initial publication in response to public comments. This document contains excerpts of the affected regulatory language and includes the double strikeout/double underline format to identify changes from the proposed amendments made available as part of the ISOR (available below).
  • Public Hearing Notice: Invitation to public and industry to discuss proposed changes to the regulations. This notice includes the date, time, location, and a summary of the issues to be covered during the hearing. ( PDF - 58K )
  • Staff Report: Initial Statement of Reasons (ISOR): Descriptions of the proposed amendments to the regulations. ( PDF - 568K )
  • Proposed OBD II Regulation section 1968.2: The regulation (Section 1968.2 of Title 13, California Code of Regulations (CCR)) incorporating the proposed amendments. This document includes the strikeout/underline format to identify changes from the current regulation. ( PDF - 699K )
  • Proposed OBD II Enforcement Regulation section 1968.5: The enforcement regulation (section 1968.5 of title 13, CCR) incorporating the proposed amendments. This document includes the strikeout/underline format to identify changes from the current regulation. ( PDF - 137K )
  • Proposed Emission Warranty Regulations sections 2035, 2037, and 2038: The emission warranty regulations (sections 2035, 2037, and 2038 of title 13, CCR) incorporating the proposed amendments. This document includes the strikeout/underline format to identify changes from the current regulations. ( PDF - 69K )


Draft OBD II Regulation Language: Released February 7, 2006

This is draft language of the proposed amendments to the OBD II regulation (section 1968.2). This document includes the "track changes" format to identify changes from the original regulation (additions are indicated by underline while deletions are indicated on the right side ). Please note that this is not the "finalized" regulation that ARB staff will be presenting at a future 2006 Board Hearing.


Documents and Presentations from OBD II Public Workshop: November 16, 2005

ARB held a public workshop on November 16, 2005, to discuss its current position and proposals regarding OBD II-related issues. ARB also discussed amendments being proposed for the emission warranty regulations. Here you will find documents and presentations pertaining to the workshop:

  • Workshop Presentations: ARB workshop presentations of the proposed changes to the regulations.
    • ARB Presentation 1: Presentation detailing changes to gasoline monitoring requirements, testing requirements, enforcement regulation, and emission warranty regulation, among other things. ( PDF - 414K )
    • ARB Presentation 2: Presentation detailing changes to diesel monitoring requirements. ( PDF - 313K )
  • Workshop Notice: Invitation to the public and industry to discuss proposed changes to the regulations. This notice indicates the date, time, location, and a summary of the issues to be covered during the workshop. ( PDF - 22K )
  • Draft OBD II Regulation: Draft regulatory language of the OBD II regulation incorporating theÏproposed amendments released November 3, 2005.
  • Draft Emission Warranty Regulation:Draft regulatory language of the emission warranty regulations incorporating the proposed amendments. ( PDF - 110K )


Past Regulatory Documents


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