[Code of Federal Regulations]
[Title 40, Volume 17]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR86.005-17]
[Page 64-70]
TITLE 40--PROTECTION OF ENVIRONMENT
CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
PART 86_CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND
ENGINES--Table of Contents
Subpart A_General Provisions for Emission Regulations for 1977 and Later
Sec. 86.005-17 On-board diagnostics.
(a) General. (1) All heavy-duty engines intended for use in a heavy-
duty vehicle weighing 14,000 pounds GVWR or less must be equipped with
an on-board diagnostic (OBD) system capable of monitoring all emission-
related engine systems or components during the applicable useful life.
Heavy-duty engines intended for use in a heavy-duty vehicle weighing
14,000 pounds GVWR or less must meet the OBD requirements of this
section according to the phase-in schedule in paragraph (k) of this
section. All monitored systems and components must be evaluated
periodically, but no less frequently than once per applicable
certification test cycle as defined in Appendix I, paragraph (f), of
this part, or similar trip as approved by the Administrator.
(2) An OBD system demonstrated to fully meet the requirements in
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Sec. 86.1806-05 may be used to meet the requirements of this section,
provided that the Administrator finds that a manufacturer's decision to
use the flexibility in this paragraph (a)(2) is based on good
engineering judgement. (b) Malfunction descriptions. The OBD system must
detect and identify malfunctions in all monitored emission-related
engine systems or components according to the following malfunction
definitions as measured and calculated in accordance with test
procedures set forth in subpart N of this part (engine-based test
procedures) excluding the test procedure referred to as the
``Supplemental emission test; test cycle and procedures'' contained in
Sec. 86.1360, and excluding the test procedure referred to as the
``Not-To-Exceed Test Procedure'' contained in Sec. 86.1370, and
excluding the test procedure referred to as the ``Load Response Test''
contained in Sec. 86.1380.
(1) Catalysts and particulate traps. (i) Otto-cycle. Catalyst
deterioration or malfunction before it results in an increase in NMHC
(or NOX+NMHC, as applicable) emissions 1.5 times the NMHC (or
NOX+NMHC, as applicable) standard or FEL, as compared to the
NMHC (or NOX+NMHC, as applicable) emission level measured
using a representative 4000 mile catalyst system.
(ii) Diesel. (A) If equipped, catalyst deterioration or malfunction
before it results in exhaust emissions exceeding 1.5 times the
applicable standard or FEL for NOX (or NOX+NMHC,
as applicable) or PM. This requirement applies only to reduction
catalysts; monitoring of oxidation catalysts is not required. This
monitoring need not be done if the manufacturer can demonstrate that
deterioration or malfunction of the system will not result in exceedance
of the threshold.
(B) If equipped with a particulate trap, catastrophic failure of the
device must be detected. Any particulate trap whose complete failure
results in exhaust emissions exceeding 1.5 times the applicable standard
or FEL for NMHC (or NOX+NMHC, as applicable) or PM must be
monitored for such catastrophic failure. This monitoring need not be
done if the manufacturer can demonstrate that a catastrophic failure of
the system will not result in exceedance of the threshold.
(2) Engine Misfire. (i) Otto-cycle. Engine misfire resulting in
exhaust emissions exceeding 1.5 times the applicable standard or FEL for
NMHC, NOX (or NOX+NMHC, as applicable) or CO; and
any misfire capable of damaging the catalytic converter.
(ii) Diesel. Lack of cylinder combustion must be detected.
(3) Oxygen sensors. If equipped, oxygen sensor deterioration or
malfunction resulting in exhaust emissions exceeding 1.5 times the
applicable standard or FEL for NMHC, NOX (or
NOX+NMHC, as applicable) or CO.
(4) Evaporative leaks. If equipped, any vapor leak in the
evaporative and/or refueling system (excluding the tubing and
connections between the purge valve and the intake manifold) greater
than or equal in magnitude to a leak caused by a 0.040 inch diameter
orifice; an absence of evaporative purge air flow from the complete
evaporative emission control system. Where fuel tank capacity is greater
than 25 gallons, the Administrator may, following a request from the
manufacturer, revise the size of the orifice to the smallest orifice
feasible, based on test data, if the most reliable monitoring method
available cannot reliably detect a system leak equal to a 0.040 inch
diameter orifice.
(5) Other emission control systems. Any deterioration or malfunction
occurring in an engine system or component directly intended to control
emissions, including but not necessarily limited to, the exhaust gas
recirculation (EGR) system, if equipped, the secondary air system, if
equipped, and the fuel control system, singularly resulting in exhaust
emissions exceeding 1.5 times the applicable emission standard or FEL
for NMHC, NOX (or NOX+NMHC, as applicable), CO or
diesel PM. For engines equipped with a secondary air system, a
functional check, as described in paragraph (b)(6) of this section, may
satisfy the requirements of this paragraph (b)(5) provided the
manufacturer can demonstrate that deterioration of the flow distribution
system is unlikely. This demonstration is subject to Administrator
approval and, if the
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demonstration and associated functional check are approved, the
diagnostic system must indicate a malfunction when some degree of
secondary airflow is not detectable in the exhaust system during the
check. For engines equipped with positive crankcase ventilation (PCV),
monitoring of the PCV system is not necessary provided the manufacturer
can demonstrate to the Administrator's satisfaction that the PCV system
is unlikely to fail.
(6) Other emission-related engine components. Any other
deterioration or malfunction occurring in an electronic emission-related
engine system or component not otherwise described above that either
provides input to or receives commands from the on-board computer and
has a measurable impact on emissions; monitoring of components required
by this paragraph (b)(6) must be satisfied by employing electrical
circuit continuity checks and rationality checks for computer input
components (input values within manufacturer specified ranges based on
other available operating parameters), and functionality checks for
computer output components (proper functional response to computer
commands) except that the Administrator may waive such a rationality or
functionality check where the manufacturer has demonstrated
infeasibility. Malfunctions are defined as a failure of the system or
component to meet the electrical circuit continuity checks or the
rationality or functionality checks.
(7) Performance of OBD functions. Oxygen sensor or any other
component deterioration or malfunction which renders that sensor or
component incapable of performing its function as part of the OBD system
must be detected and identified on vehicles so equipped.
(c) Malfunction indicator light (MIL). The OBD system must
incorporate a malfunction indicator light (MIL) readily visible to the
vehicle operator. When illuminated, the MIL must display ``Check
Engine,'' ``Service Engine Soon,'' a universally recognizable engine
symbol, or a similar phrase or symbol approved by the Administrator.
More than one general purpose malfunction indicator light for emission-
related problems should not be used; separate specific purpose warning
lights (e.g., brake system, fasten seat belt, oil pressure, etc.) are
permitted. The use of red for the OBD-related malfunction indicator
light is prohibited.
(d) MIL illumination. The MIL must illuminate and remain illuminated
when any of the conditions specified in paragraph (b) of this section
are detected and verified, or whenever the engine control enters a
default or secondary mode of operation considered abnormal for the given
engine operating conditions. The MIL must blink once per second under
any period of operation during which engine misfire is occurring and
catalyst damage is imminent. If such misfire is detected again during
the following driving cycle (i.e., operation consisting of, at a
minimum, engine start-up and engine shut-off) or the next driving cycle
in which similar conditions are encountered, the MIL must maintain a
steady illumination when the misfire is not occurring and then remain
illuminated until the MIL extinguishing criteria of this section are
satisfied. The MIL must also illuminate when the vehicle's ignition is
in the ``key-on'' position before engine starting or cranking and
extinguish after engine starting if no malfunction has previously been
detected. If a fuel system or engine misfire malfunction has previously
been detected, the MIL may be extinguished if the malfunction does not
reoccur during three subsequent sequential trips during which similar
conditions are encountered and no new malfunctions have been detected.
Similar conditions are defined as engine speed within 375 rpm, engine
load within 20 percent, and engine warm-up status equivalent to that
under which the malfunction was first detected. If any malfunction other
than a fuel system or engine misfire malfunction has been detected, the
MIL may be extinguished if the malfunction does not reoccur during three
subsequent sequential trips during which the monitoring system
responsible for illuminating the MIL functions without detecting the
malfunction, and no new malfunctions have been detected. Upon
Administrator approval, statistical MIL illumination protocols may be
employed, provided they result in comparable timeliness in detecting a
malfunction
[[Page 67]]
and evaluating system performance, i.e., three to six driving cycles
would be considered acceptable.
(e) Storing of computer codes. The OBD system shall record and store
in computer memory diagnostic trouble codes and diagnostic readiness
codes indicating the status of the emission control system. These codes
shall be available through the standardized data link connector per
specifications as referenced in paragraph (h) of this section.
(1) A diagnostic trouble code must be stored for any detected and
verified malfunction causing MIL illumination. The stored diagnostic
trouble code must identify the malfunctioning system or component as
uniquely as possible. At the manufacturer's discretion, a diagnostic
trouble code may be stored for conditions not causing MIL illumination.
Regardless, a separate code should be stored indicating the expected MIL
illumination status (i.e., MIL commanded ``ON,'' MIL commanded ``OFF'').
(2) For a single misfiring cylinder, the diagnostic trouble code(s)
must uniquely identify the cylinder, unless the manufacturer submits
data and/or engineering evaluations which adequately demonstrate that
the misfiring cylinder cannot be reliably identified under certain
operating conditions. For diesel engines only, the specific cylinder for
which combustion cannot be detected need not be identified if new
hardware would be required to do so. The diagnostic trouble code must
identify multiple misfiring cylinder conditions; under multiple misfire
conditions, the misfiring cylinders need not be uniquely identified if a
distinct multiple misfire diagnostic trouble code is stored.
(3) The diagnostic system may erase a diagnostic trouble code if the
same code is not re-registered in at least 40 engine warm-up cycles, and
the malfunction indicator light is not illuminated for that code.
(4) Separate status codes, or readiness codes, must be stored in
computer memory to identify correctly functioning emission control
systems and those emission control systems which require further engine
operation to complete proper diagnostic evaluation. A readiness code
need not be stored for those monitors that can be considered
continuously operating monitors (e.g., misfire monitor, fuel system
monitor, etc.). Readiness codes should never be set to ``not ready''
status upon key-on or key-off; intentional setting of readiness codes to
``not ready'' status via service procedures must apply to all such
codes, rather than applying to individual codes. Subject to
Administrator approval, if monitoring is disabled for a multiple number
of driving cycles (i.e., more than one) due to the continued presence of
extreme operating conditions (e.g., ambient temperatures below 40
[deg]F, or altitudes above 8000 feet), readiness for the subject
monitoring system may be set to ``ready'' status without monitoring
having been completed. Administrator approval shall be based on the
conditions for monitoring system disablement, and the number of driving
cycles specified without completion of monitoring before readiness is
indicated.
(f) Available diagnostic data. (1) Upon determination of the first
malfunction of any component or system, ``freeze frame'' engine
conditions present at the time must be stored in computer memory. Should
a subsequent fuel system or misfire malfunction occur, any previously
stored freeze frame conditions must be replaced by the fuel system or
misfire conditions (whichever occurs first). Stored engine conditions
must include, but are not limited to: engine speed, open or closed loop
operation, fuel system commands, coolant temperature, calculated load
value, fuel pressure, vehicle speed, air flow rate, and intake manifold
pressure if the information needed to determine these conditions is
available to the computer. For freeze frame storage, the manufacturer
must include the most appropriate set of conditions to facilitate
effective repairs. If the diagnostic trouble code causing the conditions
to be stored is erased in accordance with paragraph (d) of this section,
the stored engine conditions may also be erased.
(2) The following data in addition to the required freeze frame
information must be made available on demand through the serial port on
the standardized data link connector, if the information is available to
the on-board
[[Page 68]]
computer or can be determined using information available to the on-
board computer: Diagnostic trouble codes, engine coolant temperature,
fuel control system status (closed loop, open loop, other), fuel trim,
ignition timing advance, intake air temperature, manifold air pressure,
air flow rate, engine RPM, throttle position sensor output value,
secondary air status (upstream, downstream, or atmosphere), calculated
load value, vehicle speed, and fuel pressure. The signals must be
provided in standard units based on SAE specifications incorporated by
reference in paragraph (h) of this section. Actual signals must be
clearly identified separately from default value or limp home signals.
(3) For all OBD systems for which specific on-board evaluation tests
are conducted (catalyst, oxygen sensor, etc.), the results of the most
recent test performed by the vehicle, and the limits to which the system
is compared must be available through the standardized data link
connector per the appropriate standardized specifications as referenced
in paragraph (h) of this section.
(4) Access to the data required to be made available under this
section shall be unrestricted and shall not require any access codes or
devices that are only available from the manufacturer.
(g) Exceptions. The OBD system is not required to evaluate systems
or components during malfunction conditions if such evaluation would
result in a risk to safety or failure of systems or components.
Additionally, the OBD system is not required to evaluate systems or
components during operation of a power take-off unit such as a dump bed,
snow plow blade, or aerial bucket, etc.
(h) Reference materials. The OBD system shall provide for
standardized access and conform with the following Society of Automotive
Engineers (SAE) standards and/or the following International Standards
Organization (ISO) standards. The following documents are incorporated
by reference, see Sec. 86.1:
(1) SAE material. Copies of these materials may be obtained from the
Society of Automotive Engineers, Inc., 400 Commonwealth Drive,
Warrendale, PA 15096-0001.
(i) SAE J1850 ``Class B Data Communication Network Interface,''
(Revised, May 2001) shall be used as the on-board to off-board
communications protocol. All emission related messages sent to the scan
tool over a J1850 data link shall use the Cyclic Redundancy Check and
the three byte header, and shall not use inter-byte separation or check
sums.
(ii) Basic diagnostic data (as specified in Sec. 86.094-17(e) and
(f)) shall be provided in the format and units in SAE J1979 ``E/E
Diagnostic Test Modes--Equivalent to ISO/DIS 15031-5: April 30, 2002'',
(Revised, April 2002).
(iii) Diagnostic trouble codes shall be consistent with SAE J2012
``Diagnostic Trouble Code Definitions--Equivalent to ISO/DIS 15031-6:
April 30, 2002'', (Revised, April 2002).
(iv) The connection interface between the OBD system and test
equipment and diagnostic tools shall meet the functional requirements of
SAE J1962 ``Diagnostic Connector--Equivalent to ISO/DIS 15031-3:
December 14, 2001'' (Revised, April 2002).
(v) All acronyms, definitions and abbreviations shall be formatted
according to SAE J1930 ``Electrical/Electronic Systems Diagnostic Terms,
Definitions, Abbreviations, and Acronyms'' Equivalent to ISO/TR 15031-2:
April 30, 2002'', (Revised, April 2002).
(vi) All equipment used to interface, extract and display OBD-
related information shall meet SAE J1978 ``OBD II Scan Tool'' Equivalent
to ISO 15031-4: December 14, 2001'', (Revised, April 2002).
(vii) As an alternative to the above standards, heavy-duty vehicles
may conform to the specifications of the SAE J1939 series of standards
(SAE J1939-11, J1939-13, J1939-21, J1939-31, J1939-71, J1939-73, J1939-
81).
(2) ISO materials. Copies of these materials may be obtained from
the International Organization for Standardization, Case Postale 56, CH-
1211 Geneva 20, Switzerland.
(i) ISO 9141-2 ``Road vehicles--Diagnostic systems--Part 2: CARB
requirements for interchange of digital information,'' (February 1,
1994) may be used as an alternative to SAE J1850 as the
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on-board to off-board communications protocol.
(ii) ISO 14230-4:2000(E) ``Road vehicles--Diagnostic systems--KWP
2000 requirements for Emission-related systems'', (June 1, 2000) may
also be used as an alternative to SAE J1850.
(iii) ISO 15765-4.3:2001 ``Road Vehicles-Diagnostics on Controller
Area Network (CAN)--Part 4: Requirements for emission-related systems'',
(December 14, 2001) may also be used as an alternative to SAE J1850.
(i) Deficiencies and alternate fueled engines. Upon application by
the manufacturer, the Administrator may accept an OBD system as
compliant even though specific requirements are not fully met. Such
compliances without meeting specific requirements, or deficiencies, will
be granted only if compliance would be infeasible or unreasonable
considering such factors as, but not limited to: technical feasibility
of the given monitor and lead time and production cycles including
phase-in or phase-out of engines or vehicle designs and programmed
upgrades of computers. Unmet requirements should not be carried over
from the previous model year except where unreasonable hardware or
software modifications would be necessary to correct the deficiency, and
the manufacturer has demonstrated an acceptable level of effort toward
compliance as determined by the Administrator. Furthermore, EPA will not
accept any deficiency requests that include the complete lack of a major
diagnostic monitor (``major'' diagnostic monitors being those for
exhaust aftertreatment devices, oxygen sensor, engine misfire,
evaporative leaks, and diesel EGR, if equipped), with the possible
exception of the special provisions for alternate fueled engines. For
alternate fueled heavy-duty engines (e.g. natural gas, liquefied
petroleum gas, methanol, ethanol), beginning with the model year for
which alternate fuel emission standards are applicable and extending
through the 2006 model year, manufacturers may request the Administrator
to waive specific monitoring requirements of this section for which
monitoring may not be reliable with respect to the use of the alternate
fuel. At a minimum, alternate fuel engines must be equipped with an OBD
system meeting OBD requirements to the extent feasible as approved by
the Administrator.
(j) California OBDII compliance option. For heavy-duty engines
weighing 14,000 pounds GVWR or less, demonstration of compliance with
California OBD II requirements (Title 13 California Code of Regulations
Sec. 1968.2 (13 CCR 1968.2)), as modified pursuant to CARB Mail-Out
MSCD 02-11 (internet posting date October 7, 2002), shall
satisfy the requirements of this section, except that compliance with 13
CCR 1968.2(e)(4.2.2)(C), pertaining to 0.02 inch evaporative leak
detection, and 13 CCR 1968.2(d)(1.4), pertaining to tampering
protection, are not required to satisfy the requirements of this
section. Also, the deficiency provisions of 13 CCR 1968.2(i) do not
apply. The deficiency provisions of paragraph (i) of this section and
the evaporative leak detection requirement of paragraph (b)(4) of this
section apply to manufacturers selecting this paragraph for
demonstrating compliance. In addition, demonstration of compliance with
13 CCR 1968.2(e)(16.2.1)(C), to the extent it applies to the
verification of proper alignment between the camshaft and crankshaft,
applies only to vehicles equipped with variable valve timing.
(k) Phase-in for heavy-duty engines. Manufacturers of heavy-duty
engines must comply with the OBD requirements in this section according
to the following phase-in schedule, based on the percentage of projected
engine sales within each category. The 2004 model year requirements in
the following phase-in schedule are applicable only to heavy-duty Otto-
cycle engines where the manufacturer has selected Otto-cycle Option 1 or
Option 2 for alternative 2004 compliance according to Sec. 86.005-
01(c)(1) or (2). The 2005 through 2007 requirements in the following
phase-in schedule apply to all heavy-duty engines intended for use in a
heavy-duty vehicle weighing 14,000 pounds GVWR or less. Manufacturers
may exempt 2005 model year diesel heavy-duty engines from the
requirements of this section if the 2005 model year commences before
July 31, 2004 from the requirements of this section. Manufacturers may
exempt 2005 model year Otto-cycle heavy-duty engines
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and vehicles from the requirements of this section if the manufacturer
has selected Otto-cycle Option 3 and if the 2005 model year commences
before July 31, 2004. For the purposes of calculating compliance with
the phase-in provisions of this paragraph (k), heavy-duty engines may be
combined with heavy-duty vehicles subject to the phase-in requirements
of paragraph Sec. 86.1806-05(l). The OBD Compliance phase-in table
follows:
OBD Compliance Phase-in for Heavy-Duty Engines Intended for Use in a
Heavy-Duty Vehicle Weighing 14,000 Pounds GVWR or Less
------------------------------------------------------------------------
Otto-cycle phase-in Diesel Phase-in
Model year based on projected based on projected
sales sales
------------------------------------------------------------------------
2004 MY..................... Applicable only to ....................
Otto-cycle engines
complying with
Options 1 or 2; 40%
compliance;
alternative fuel
waivers available.
2005 MY..................... 60% compliance; 50% compliance;
alternative fuel alternative fuel
waivers available. waivers available.
2006 MY..................... 80% compliance; 50% compliance;
alternative fuel alternative fuel
waivers available. waivers available.
2007 MY..................... 80% compliance; 100% compliance.
alternative fuel
waivers available.
2008+ MY.................... 100% compliance..... 100% compliance.
------------------------------------------------------------------------
[65 FR 59951, Oct. 6, 2000, as amended at 66 FR 5160, Jan. 18, 2001]