U.S. Environmental Protection Agency
Office of Mobile Sources

November 7, 1997 
VPCD-97-10 
(LDT/LDV/SM/ICI/LIMO)

Dear Manufacturer:

SUBJECT: On-Board Diagnostics (OBD) Notice of Proposed
Rulemaking to Accept California OBD II Requirements
beyond the 1998 Model Year

On May 28, 1997, the Agency published in the Federal Register a
notice of proposed rulemaking (62 FR 28932) that proposed, in
part, to indefinitely accept optional compliance with the
California OBD II requirements as satisfying federal OBD
requirements. This proposed revision to the federal OBD
requirements, if finalized, is intended to continue that widely
utilized certification compliance option for 1999 model year
certification and beyond, rather than eliminating that option
with the 1999 model year as do the current federal OBD
regulations. Given the widespread utilization of that compliance
option (only one major automobile manufacturer is selling
vehicles certified specifically to the EPA OBD requirements
rather than choosing the California OBD II option), and the
likelihood that the final rulemaking extending this compliance
option will not be published in time for 1999 model year
certification, it is possible that a majority of the U.S. vehicle
fleet will be uncertifiable for the 1999 model year unless the
Agency puts in place an interim policy to address this issue.

Therefore, my staff has developed the following interim policy to
deal with certification requests prior to publication of the
final rulemaking: All certification requests that choose the
California OBD II compliance option for demonstrating compliance
with federal OBD requirements must include a statement from the
manufacturer that the OBD system meets the full intent of both
the Clean Air Act as amended in 1990, section 202(m), and the
federal OBD regulations contained in 40 CFR 86.098-17, and that
the OBD system fulfills the requirements of 40 CFR 86.098-17
including those provisions pertaining to requests for
deficiencies. Please note that such a statement will be
necessary for each and every certification application choosing
the California OBD II option, and that no such application will
be approved for the 1999 model year without carrying with it such
a statement.

If you have any questions concerning this letter or the status of
our OBD rulemaking development efforts, please contact Todd
Sherwood of my staff at 313 668-4405.

Sincerely,

Jane Armstrong, Director
Vehicle Programs and Compliance Division