percent. The emissions reductions associated with this program are estimated
             to result in over $70 billion in public health and welfare benefits through reduced
             hospitalizations and lost work days. The proposed OBD requirements will help to
             ensure that these benefits are realized.

             On February 19, 1993, EPA published a final rule requiring manufacturers of
             passenger vehicles to install OBD systems on vehicles beginning with the 1994
             model year (58 FR 9468). The OBD systems must monitor emission control
             components for any malfunction or deterioration that could cause exceedance of
             certain emission thresholds. The regulation also required driver notification of any
             need for repair via a dashboard light, or malfunction indicator light (MIL), when
             the diagnostic system detected a problem. This is commonly referred to as the
             "Check Engine" light.

             On August 9, 1995, EPA published a rulemaking that set forth automotive
             service information requirements for light-duty vehicles and light-duty trucks
             (60 FR 40474). These regulations, in part, required each Original Equipment
             Manufacturer (OEM) to list all emission-related service and repair information
             on a Web site and explain how to obtain that information and at what cost. The
             intent of this provision is to ensure that aftermarket service and repair facilities
             have access to the same emission-related service information, in the same or
             similar manner, as that provided by OEMs to their franchised dealerships. These
             service information availability requirements have been revised since the  1995
             rule in response to changing technology (68 FR 38428).

             In October 2000, EPA published a rule requiring OBD systems on heavy-duty
             vehicles and engines up to 14,000 pounds gross vehicle weight rating (GVWR)
             (65 FR 59896). In that rule, EPA expressed  its intention to develop in a future
             rule OBD requirements for vehicles and engines used in vehicles over 14,000
             pounds. EPA again expressed this same intention in its Clean Diesel Truck and
             Bus rule (66 FR 5002) which established new heavy-duty highway emissions
             standards for 2007 and later model year engines.

             In June 2003, EPA published a rule extending service information availability
             requirements to heavy-duty vehicles and engines weighing up to 14,000 pounds
             GVWR. EPA did not extend these requirements to engines above 14,000  pounds
             GVWR, deciding to wait until such engines were subject to OBD requirements.
       Overview of Proposal
       The proposal requires manufacturers to install OBD systems that monitor the function
       of emission control components and alert the vehicle operator to any detected need for
       emission related repair. In addition, when a malfunction occurs, diagnostic information
       must be stored in the engine's computer to assist in diagnosis and repair of the
       malfunction. Also proposed are requirements that would make available to the service
Proposed OBD Requirements for Heavy-Duty Engines

       and repair industry information necessary to perform repair and maintenance service
       on OBD systems and other emission related engine components. These proposed
       requirements will help to ensure that the significant benefits of EPA's Clean Diesel
       Program exhaust emission standards will be realized in-use. Specifically:

          •  For 2010 and later model year heavy-duty diesel and gasoline engines used in
             trucks and buses over 14,000 pounds, we are proposing that all  major emissions
             control systems be monitored and malfunctions be detected prior to emissions
             exceeding a set of emissions thresholds. Most notably, we are requiring that the
             aftertreatment devices—e.g., the diesel particulate filters and oxides of  nitrogen
             (NOx) reducing catalysts—that will be used on highway  diesel engines to comply
             with the 2010 emissions standards will  be monitored and their failure will be
             detected and noted to the driver. We are also proposing  that all emission-related
             electronic sensors and actuators be monitored for proper operation.

          •  For 2010 and later highway vehicles over 14,000 pounds, we are proposing
             that one engine family per manufacturer be certified to the proposed OBD
             requirements in the 2010 through 2012  model years. Beginning in 2013,  all
             highway engines for all manufacturers would have to be certified to the  proposed
             OBD requirements. This phase-in is  designed to spread over a number of years
             the development effort required by industry and to provide industry with a
             learning period prior to implementing the OBD requirements on 100 percent of
             their highway product line.

          •  For vehicles over 14,000 pounds,  the service information availability
             requirements would apply for those engines certified to  the OBD requirements.

          •  For 2010 and later model year highway  heavy-duty diesel vehicles under 14,000
             pounds, we  are proposing a new  emissions threshold for monitoring of the
             diesel particulate filter. The existing requirement for these  applications is to
             detect a catastrophic failure of the device. We believe now that a more stringent
             requirement is appropriate and feasible. The proposed emissions threshold is
             consistent, both in  stringency and in timing, with the proposed particulate matter
             (PM) thresholds for over 14,000 pound  applications.

          •  For 2007 and later model year highway  heavy-duty diesel vehicles under 14,000
             pounds, we  are proposing a change to the existing emissions thresholds for
             NOx emissions. The existing thresholds, typically 1.5 times the applicable
             NOx standard, were established when  the engine's NOx standard was much
             higher than today's very low level. We believe these OBD thresholds are not
             technologically feasible in the context of EPA's very stringent NOx emission
             standards, and this proposal addresses that issue.

       For heavy-duty diesel engines used in nonroad equipment, we  are seeking comment
       on possible future regulations that would require OBD systems. Diesel engines used
Proposed OBD Requirements for Heavy-Duty Engines

       in nonroad equipment are, like highway engines, a major source of NOx and PM
       emissions, and the diesel engines used in nonroad equipment are essentially the same
       as those used in heavy-duty highway trucks. Further, new regulations applicable to
       nonroad diesel engines will result in the introduction of advanced emissions control
       systems like those expected for highway diesel engines. (69 FR 38958) Therefore,
       having OBD systems and OBD regulations for nonroad engines seems to be a natural
       progression from the proposed requirements for heavy-duty highway engines.
       Health  and Environmental Effects
          •  In our 2007 Clean Diesel Truck and  Bus rule, we estimated that the new 2007
             emission standards will result in substantial benefits to the public health
             and welfare through significant annual reductions in emissions of NOx, PM,
             nonmethane hydrocarbons (NMHC), carbon monoxide, sulfur dioxide, and air
             toxics. These emission reductions will prevent 8,300 premature deaths, more
             than 9,500 hospitalizations, and 1.5 million work days lost. This OBD proposal will
             help to ensure that these projected benefits will be realized.

          •  As a result of this program, each new truck and bus will be  more than 90
             percent cleaner than current models. We project a 2.6 million ton reduction of
             NOx emissions in 2030 when the current heavy-duty vehicle fleet is completely
             replaced with newer heavy-duty vehicles that comply with the 2007 program's
             emission standards. By 2030, the program will reduce annual emissions of
             NMHC by 115,000 tons and PM by 109,000 tons.

          •  Ozone causes a range of health problems related to breathing, including chest
             pain, coughing, and shortness of breath. PM is deposited deep  in the lungs
             and causes premature death, increased emergency room visits, and increased
             respiratory symptoms and disease. With both  ozone and PM, children and the
             elderly are most at risk. In addition, ozone,  NOx, and PM adversely affect the
             environment in various ways, including crop damage, acid rain, and visibility

          •  We have not estimated new emissions reductions associated with this proposal.
             We consider OBD to be a critical element to an overall emissions control
             program. As such, OBD requirements and their associated  benefits were
             assumed in our estimated emissions reductions associated with the 2007 Clean
             Diesel Truck and Bus Program.
       Cost Effects
       We project that the proposed OBD requirements will result in an increased cost of
       roughly $50 per diesel engine and $60 per gasoline engine used in applications over
       14,000 pounds. We project that the proposed new requirements for diesel heavy-duty
       applications under 14,000 pounds will cost roughly $5 per engine or vehicle.

Proposed OBD Requirements for Heavy-Duty Engines

       Public Participation  Opportunities
       We welcome your comments on this proposed rule. Comments will be accepted for 60
       days beginning when this proposal is published in the Federal Register. All comments
       should be identified by Docket ID No. EPA-HQ-OAR-2005-0047 and submitted by one of
       the following methods:

          •  Internet: www.regulations.gov

          •  E-mail:  A-and-R-Docket@epa.gov

          •  Mail:
                Environmental Protection Agency
                EPA Docket Center (EPA/DC)
                Air and Radiation Docket and Information Center
                1700 Pennsylvania  Avenue NW
                Washington, DC 20460

          •  Hand delivery:
                EPA Docket Center
                EPA West  Building
                Room 3340
                1301  Constitution Avenue NW
                Washington, DC
       For More Information
       You can access the proposed rule and related documents on EPAs Office of
       Transportation and Air Quality (OTAQ) Web site at:

       For additional information specific to OBD, please contact:

          •   Todd Sherwood
             U.S. Environmental Protection Agency
             National Vehicle and Fuels Emission Laboratory
             Assessment and Standards Division
             2000Traverwood, Ann Arbor, Ml 48105
             phone: 734-214-4405
             fax:    734-214-4816
             E-mail: sherwood.todd@epa.gov
Proposed OBD Requirements for Heavy-Duty Engines

       For additional information specific to service information availability, please contact:

           •   Holly Pugliese
              U.S. Environmental Protection Agency
              National Vehicle and Fuels Emission Laboratory
              Compliance and Innovative Strategies Division
              2000Traverwood, Ann Arbor, Ml 48105
              phone:  734-214-4288
              fax:    734-214-4869
              E-mail:  pualiese.hollv@epa.aov
Proposed OBD Requirements for Heavy-Duty Engines