than misfire, the MIL must still blink once per second at all times
during the drive cycle that engine misfire is occurring. If misfire
ceases, the MIL must stop blinking but remain activated as appropriate
in accordance with the other malfunction.

MIL-on DTCs. If a pending DTC is stored in accordance with paragraph
(h)(2)(iv)(A) of this section, the OBD system must immediately store a
MIL-on DTC if the percentage of misfire described in paragraph
(h)(2)(ii)(A) of this section is again exceeded one or more times during
either the drive cycle immediately following storage of the pending DTC,
regardless of the conditions encountered during that drive cycle, or on
the next drive cycle in which similar conditions are encountered to
those that occurred when the pending DTC was stored. If, during a
previous drive cycle, a pending DTC is stored in accordance with
paragraph (h)(2)(iv)(A) of this section, a MIL-on DTC must be stored
immediately upon exceeding the percentage misfire described in paragraph
(h)(2)(ii)(A) of this section regardless of the conditions encountered.
Upon storage of a MIL-on DTC, the MIL must blink once per second at all
times during the drive cycle that engine misfire is occurring. If
misfire ceases, the MIL must stop blinking but remain activated until
the conditions are met for extinguishing the MIL.

Erasure of pending DTCs. Pending DTCs stored in accordance with
paragraph (h)(2)(iv)(A) of this section must be erased at the end of the
next drive cycle in which similar conditions are encountered to those
that occurred when the pending DTC was stored provided no exceedances
have been detected of the misfire percentage described in paragraph
(h)(2)(ii)(A) of this section. The pending DTC may also be erased if
similar conditions are not encountered during the next 80 drive cycles
immediately following storage of the pending DTC.

Exemptions for engines with fuel shutoff and default fuel control. In
engines that provide for fuel shutoff and default fuel control to
prevent over fueling during catalyst damaging misfire conditions, the
MIL need not blink as required by paragraphs (h)(2)(iv)(A) and
(h)(2)(iv)(B) of this section. Instead, the MIL may be activated
continuously upon misfire detection provided that the fuel shutoff and
default fuel control are activated immediately upon misfire detection.
Fuel shutoff and default fuel control may be deactivated only when the
engine is outside of the misfire range except that the manufacturer may
periodically, but not more than once every 30 seconds, deactivate fuel
shutoff and default fuel control to determine if the catalyst damaging
misfire is still occurring.  Normal fueling and fuel control may be
resumed if the catalyst damaging misfire is no longer occurring.

The manufacturer may use a strategy that activates the MIL continuously
rather than blinking the MIL during extreme catalyst damage misfire
conditions (i.e., catalyst damage misfire occurring at all engine speeds
and loads).  Use of such a strategy must be limited to catalyst damage
misfire levels that cannot be avoided during reasonable driving
conditions.  To use such a strategy, the manufacturer must be able to
demonstrate that the strategy will encourage operation of the vehicle in
conditions that will minimize catalyst damage (e.g., at low engine
speeds and loads).

MIL activation and DTC storage for engine misfire causing emissions to
exceed applicable emissions thresholds.

Immediately upon detection, during the first 1000 revolutions after
engine start of the misfire percentage described in paragraph
(h)(2)(ii)(B) of this section, a pending DTC must be stored. If such a
pending DTC is stored already and another such exceedance of the misfire
percentage is detected within the first 1000 revolutions after engine
start on any subsequent drive cycle, the MIL must activate and a MIL-on
DTC must be stored. The pending DTC may be erased if, at the end of the
next drive cycle in which similar conditions are encountered to those
that occurred when the pending DTC was stored, there has been no
exceedance of the misfire percentage described in paragraph
(h)(2)(ii)(B) of this section. The pending DTC may also be erased if
similar conditions are not encountered during the next 80 drive cycles
immediately following storage of the pending DTC.

No later than the fourth detection during a single drive cycle,
following the first 1000 revolutions after engine start of the misfire
percentage described in paragraph (h)(2)(ii)(B) of this section, a
pending DTC must be stored. If such a pending DTC is stored already,
then the MIL must activate and a MIL-on DTC must be stored within 10
seconds of the fourth detection of the misfire percentage described in
paragraph (h)(2)(ii)(B) of this section during either the drive cycle
immediately following storage of the pending DTC, regardless of the
conditions encountered during that drive cycle excepting those
conditions within the first 1000 revolutions after engine start, or on
the next drive cycle in which similar conditions are encountered to
those that occurred when the pending DTC was stored excepting those
conditions within the first 1000 revolutions after engine start. The
pending DTC may be erased if, at the end of the next drive cycle in
which similar conditions are encountered to those that occurred when the
pending DTC was stored, there has been no exceedance of the misfire
percentage described in paragraph (h)(2)(ii)(B) of this section. The
pending DTC may also be erased if similar conditions are not encountered
during the next 80 drive cycles immediately following storage of the
pending DTC.

Storage of freeze frame conditions for engine misfire.

The OBD system must store and erase freeze frame conditions (as defined
in paragraph (k)(4)(iii) of this section) either in conjunction with
storing and erasing a pending DTC or in conjunction with storing and
erasing a MIL-on DTC.

If, upon storage of a DTC as required by paragraphs (h)(2)(iv) and
(h)(2)(v) of this section, there already exist stored freeze frame
conditions for a malfunction other than a misfire or fuel system
malfunction (see paragraph (h)(1) of this section) then the stored
freeze frame information shall be replaced with freeze frame information
associated with the misfire malfunction.

Storage of engine conditions in association with engine misfire. Upon
detection of the misfire percentages described in paragraphs
(h)(2)(ii)(A) and (h)(2)(ii)(B) of this section, the following engine
conditions must be stored for use in determining similar conditions:
engine speed, load, and warm up status of the first misfire event that
resulted in pending DTC storage.

MIL deactivation in association with engine misfire. The MIL may be
deactivated after three sequential drive cycles in which similar
conditions have been encountered without an exceedance of the misfire
percentages described in paragraphs (h)(2)(ii)(A) and (h)(2)(ii)(B) of
this section.

(h)(3) EGR system

Exhaust gas recirculation system monitoring.

General. The OBD system must monitor the EGR system on engines so
equipped for low and high flow rate malfunctions.  The individual
electronic components (e.g., actuators, valves, sensors) that are used
in the EGR system must be monitored in accordance with the comprehensive
component requirements in paragraph (i)(3) of this section.

EGR system malfunction criteria.

The OBD system must detect a malfunction of the EGR system prior to a
decrease from the manufacturer’s specified EGR flow rate that would
cause an engine’s emissions to exceed the emissions thresholds for
“other monitors” as shown in Table 2 of this paragraph (h).  For
engines in which no failure or deterioration of the EGR system that
causes a decrease in flow could result in an engine’s emissions
exceeding the applicable emissions thresholds, the OBD system must
detect a malfunction when the system has no detectable amount of EGR
flow.

The OBD system must detect a malfunction of the EGR system prior to an
increase from the manufacturer’s specified EGR flow rate that would
cause an engine’s emissions to exceed the emissions thresholds for
“other monitors” as shown in Table 2 of this paragraph (h).  For
engines in which no failure or deterioration of the EGR system that
causes an increase in flow could result in an engine’s emissions
exceeding the applicable emissions thresholds, the OBD system must
detect a malfunction when the system has reached its control limits such
that it cannot reduce EGR flow.

EGR system monitoring conditions.

The manufacturer must define the monitoring conditions for malfunctions
identified in paragraph (h)(3)(ii) of this section in accordance with
paragraphs (c) and  (d) of this section. For purposes of tracking and
reporting as required by paragraph (d)(1) of this section, all monitors
used to detect malfunctions identified in paragraph (h)(3)(ii) of this
section must be tracked separately but reported as a single set of
values as specified in paragraph (e)(1)(iii) of this section.

The manufacturer may disable temporarily the EGR monitor under
conditions when monitoring may not be reliable (e.g., when freezing may
affect performance of the system). To do so, the manufacturer must be
able to demonstrate that the monitor is unreliable when such conditions
exist.

EGR system MIL activation and DTC storage.  The MIL must activate and
DTCs must be stored according to the provisions of paragraph (b) of this
section.

(h)(4) Cold start strategy

Cold start emission reduction strategy monitoring.

General. If an engine incorporates a specific engine control strategy to
reduce cold start emissions, the OBD system must monitor the key
components (e.g., idle air control valve), other than secondary air,
while the control strategy is active to ensure proper operation of the
control strategy.

Cold start strategy malfunction criteria.

The OBD system must detect a malfunction prior to any failure or
deterioration of the individual components associated with the cold
start emission reduction control strategy that would cause an engine’s
emissions to exceed the emissions thresholds for “other monitors” as
shown in Table 2 of this paragraph (h).  The manufacturer must establish
the malfunction criteria based on data from one or more representative
engine(s) and provide an engineering evaluation for establishing the
malfunction criteria for the remainder of the manufacturer’s product
line.

Where no failure or deterioration of a component used for the cold start
emission reduction strategy could result in an engine’s emissions
exceeding the applicable emissions thresholds, the individual component
must be monitored for proper functional response while the control
strategy is active in accordance with the malfunction criteria in
paragraphs (i)(3)(ii) and (i)(3)(iii) of this section.

Cold start strategy monitoring conditions. The manufacturer must define
monitoring conditions for malfunctions identified in paragraph
(h)(4)(ii) of this section in accordance with paragraphs (c) and  (d) of
this section.

Cold start strategy MIL activation and DTC storage. The MIL must
activate and DTCs must be stored according to the provisions of
paragraph (b) of this section.

(h)(5) Secondary air system

Secondary air system monitoring.

General. The OBD system on engines equipped with any form of secondary
air delivery system must monitor the proper functioning of the secondary
air delivery system including all air switching valves(s). The
individual electronic components (e.g., actuators, valves, sensors) that
are used in the secondary air system must be monitored in accordance
with the comprehensive component requirements in paragraph (i)(3) of
this section. For purposes of this paragraph (h)(5), “air flow” is
defined as the air flow delivered by the secondary air system to the
exhaust system.  For engines using secondary air systems with multiple
air flow paths/distribution points, the air flow to each bank (i.e., a
group of cylinders that share a common exhaust manifold, catalyst, and
control sensor) must be monitored in accordance with the malfunction
criteria in paragraph (h)(5)(ii) of this section. Also for purposes of
this paragraph (h)(5), “normal operation” is defined as the
condition when the secondary air system is activated during catalyst
and/or engine warm-up following engine start.  “Normal operation”
does not include the condition when the secondary air system is turned
on intrusively for the sole purpose of monitoring.

Secondary air system malfunction criteria.

Except as provided in paragraph (h)(5)(ii)(C) of this section, the OBD
system must detect a secondary air system malfunction prior to a
decrease from the manufacturer’s specified air flow during normal
operation that would cause an engine’s emissions to exceed the
emissions thresholds for “other monitors” as shown in Table 2 of
this paragraph (h).

Except as provided in paragraph (h)(5)(ii)(C) of this section, the OBD
system must detect a secondary air system malfunction prior to an
increase from the manufacturer’s specified air flow during normal
operation that would cause an engine’s emissions to exceed the
emissions thresholds for “other monitors” as shown in Table 2 of
this paragraph (h).

For engines in which no deterioration or failure of the secondary air
system would result in an engine’s emissions exceeding the applicable
emissions thresholds, the OBD system must detect a malfunction when no
detectable amount of air flow is delivered by the secondary air system
during normal operation.

Secondary air system monitoring conditions. The manufacturer must define
monitoring conditions for malfunctions identified in paragraph
(h)(5)(ii) of this section in accordance with paragraphs (c) and  (d) of
this section. For purposes of tracking and reporting as required by
paragraph (d)(1) of this section, all monitors used to detect
malfunctions identified in paragraph (h)(5)(ii) of this section must be
tracked separately but reported as a single set of values as specified
in paragraph (e)(1)(iii) of this section.

Secondary air system MIL activation and DTC storage. The MIL must
activate and DTCs must be stored according to the provisions of
paragraph (b) of this section.

(h)(6) Catalyst system

Catalyst system monitoring.

General. The OBD system must monitor the catalyst system for proper
conversion capability.

Catalyst system malfunction criteria. The OBD system must detect a
catalyst system malfunction when the catalyst system’s conversion
capability decreases to the point that emissions exceed the emissions
thresholds for the catalyst system as shown in Table 2 of this paragraph
(h).

Catalyst system monitoring conditions. The manufacturer must define
monitoring conditions for malfunctions identified in paragraph
(h)(6)(ii) of this section in accordance with paragraphs (c) and  (d) of
this section. For purposes of tracking and reporting as required by
paragraph (d)(1) of this section, all monitors used to detect
malfunctions identified in paragraph (h)(6)(ii) of this section must be
tracked separately but reported as a single set of values as specified
in paragraph (e)(1)(iii) of this section.

Catalyst system MIL activation and DTC storage.

The MIL must activate and DTCs must be stored according to the
provisions of paragraph (b) of this section.

The monitoring method for the catalyst system must be capable of
detecting when a catalyst DTC has been erased (except OBD system self
erasure), but the catalyst has not been replaced (e.g., catalyst
overtemperature histogram approaches are not acceptable).

(h)(7) Evaporative system

Evaporative system monitoring.

General. The OBD system must verify purge flow from the evaporative
system and monitor the complete evaporative system, excluding the tubing
and connections between the purge valve and the intake manifold, for
vapor leaks to the atmosphere.  Individual components of the evaporative
system (e.g. valves, sensors) must be monitored in accordance with the
comprehensive components requirements in paragraph (i)(3) of this
section.

Evaporative system malfunction criteria.

Purge monitor. The OBD system must detect an evaporative system
malfunction when no purge flow from the evaporative system to the engine
can be detected by the OBD system.

Leak monitor. The OBD system must detect an evaporative system
malfunction when the complete evaporative system contains a leak or
leaks that cumulatively are greater than or equal to a leak caused by a
0.150 inch diameter hole.

The manufacturer may demonstrate that detection of a larger hole is more
appropriate than that specified in paragraph (h)(7)(ii)(B) of this
section. To do so, the manufacturer must demonstrate through data and/or
engineering analyses that holes smaller than the proposed detection size
would not result in evaporative or running loss emissions that exceed
1.5 times the applicable evaporative emissions standards. Upon such a
demonstration, the proposed detection size could be substituted for the
requirement of paragraph (h)(7)(ii)(B) of this section.

Evaporative system monitoring conditions.

The manufacturer must define monitoring conditions for malfunctions
identified in paragraph (h)(7)(ii)(A) of this section in accordance with
paragraphs (c) and  (d) of this section.

The manufacturer must define monitoring conditions for malfunctions
identified in paragraph (h)(7)(ii)(B) of this section in accordance with
paragraphs (c) and  (d) of this section. For purposes of tracking and
reporting as required by paragraph (d)(1) of this section, all monitors
used to detect malfunctions identified in paragraph (h)(7)(ii)(B) of
this section must be tracked separately but reported as a single set of
values as specified in paragraph (e)(1)(iii) of this section.

The manufacturer may disable or abort an evaporative system monitor when
the fuel tank level is over 85 percent of nominal tank capacity or
during a refueling event.

The manufacturer may request Administrator approval to run the
evaporative system monitor during only those drive cycles characterized
as cold starts provided such a condition is needed to ensure reliable
monitoring. In making the request, the manufacturer must demonstrate
through data and/or engineering analyses that a reliable monitor can
only be run on drive cycles that begin with a specific set of cold start
criteria. A set of cold start criteria based solely on ambient
temperature exceeding engine coolant temperature will not be acceptable.

The OBD system may disable temporarily the evaporative purge system to
run an evaporative system leak monitor.

Evaporative system MIL activation and DTC storage.

Except as provided for in paragraph (h)(7)(iv)(B) of this section, the
MIL must activate and DTCs must be stored according to the provisions of
paragraph (b) of this section.

If the OBD system is capable of discerning that a system leak is being
caused by a missing or improperly secured gas cap, the OBD system need
not activate the MIL or store a DTC provided the vehicle is equipped
with an alternative indicator for notifying the operator of the gas cap
problem. The alternative indicator must be of sufficient illumination
and location to be readily visible under all lighting conditions. If the
vehicle is not equipped with such an alternative indicator, the MIL must
activate and a DTC be stored as required in paragraph (h)(7)(iv)(A) of
this section; however, these may be deactivated and erased,
respectively, if the OBD system determines that the gas cap problem has
been corrected and the MIL has not been activated for any other
malfunction. The Administrator may approve other strategies that provide
equivalent assurance that a vehicle operator will be notified promptly
of a missing or improperly secured gas cap and that corrective action
will be undertaken.

(h)(8) Exhaust gas sensors

Exhaust gas sensor monitoring.

General.

The OBD system must monitor for malfunctions the output signal, response
rate, and any other parameter that can affect emissions of all primary
(i.e., fuel control) exhaust gas sensors (e.g., oxygen, wide-range
air/fuel). Both the lean-to-rich and rich-to-lean response rates must be
monitored.

The OBD system must also monitor all secondary exhaust gas sensors
(those used for secondary fuel trim control or as a monitoring device)
for proper output signal, activity, and response rate.

For engines equipped with heated exhaust gas sensor, the OBD system must
monitor the heater for proper performance.

Primary exhaust gas sensor malfunction criteria.

The OBD system must detect a malfunction prior to any failure or
deterioration of the exhaust gas sensor output voltage, resistance,
impedance, current, response rate, amplitude, offset, or other
characteristic(s) (including drift or bias corrected for by secondary
sensors) that would cause an engine’s emissions to exceed the
emissions thresholds for “other monitors” as shown in Table 2 of
this paragraph (h).

The OBD system must detect malfunctions of the exhaust gas sensor caused
by either a lack of circuit continuity or out-of-range values.

The OBD system must detect a malfunction of the exhaust gas sensor when
a sensor failure or deterioration causes the fuel system to stop using
that sensor as a feedback input (e.g., causes default or open-loop
operation).

The OBD system must detect a malfunction of the exhaust gas sensor when
the sensor output voltage, resistance, impedance, current, amplitude,
activity, or other characteristics are no longer sufficient for use as
an OBD system monitoring device (e.g., for catalyst monitoring).

Secondary exhaust gas sensor malfunction criteria.

The OBD system must detect a malfunction prior to any failure or
deterioration of the exhaust gas sensor voltage, resistance, impedance,
current, response rate, amplitude, offset, or other characteristic(s)
that would cause an engine’s emissions to exceed the emissions
thresholds for “other monitors” as shown in Table 2 of this
paragraph (h).

The OBD system must detect malfunctions of the exhaust gas sensor caused
by a lack of circuit continuity.

To the extent feasible, the OBD system must detect a malfunction of the
exhaust gas sensor when the sensor output voltage, resistance,
impedance, current, amplitude, activity, offset, or other
characteristics are no longer sufficient for use as an OBD system
monitoring device (e.g., for catalyst monitoring).

The OBD system must detect malfunctions of the exhaust gas sensor caused
by out-of-range values.

The OBD system must detect a malfunction of the exhaust gas sensor when
a sensor failure or deterioration causes the fuel system (e.g., fuel
control) to stop using that sensor as a feedback input (e.g., causes
default or open-loop operation).

Exhaust gas sensor heater malfunction criteria.

The OBD system must detect a malfunction of the heater performance when
the current or voltage drop in the heater circuit is no longer within
the manufacturer’s specified limits for normal operation (i.e., within
the criteria required to be met by the component vendor for heater
circuit performance at high mileage).  Other malfunction criteria for
heater performance malfunctions may be used upon demonstrating via data
or engineering analyses that the monitoring reliability and timeliness
is equivalent to the stated criteria in this paragraph (h)(8)(iv)(A).

The OBD system must detect malfunctions of the heater circuit including
open or short circuits that conflict with the commanded state of the
heater (e.g., shorted to 12 Volts when commanded to 0 Volts (ground)).

Primary exhaust gas sensor monitoring conditions.

The manufacturer must define monitoring conditions for malfunctions
identified in paragraphs (h)(8)(ii)(A) and (h)(8)(ii)(D) of this section
in accordance with paragraphs (c) and  (d) of this section. For purposes
of tracking and reporting as required by paragraph (d)(1) of this
section, all monitors used to detect malfunctions identified in
paragraphs (h)(8)(ii)(A) and (h)(8)(ii)(D) of this section must be
tracked separately but reported as a single set of values as specified
in paragraph (e)(1)(iii) of this section.

Except as provided for in paragraph (h)(8)(v)(C) of this section,
monitoring for malfunctions identified in paragraphs (h)(8)(ii)(B) and
(h)(8)(ii)(C) of this section must be conducted continuously.

The manufacturer may disable continuous primary exhaust gas sensor
monitoring when a primary exhaust gas sensor malfunction cannot be
distinguished from other effects (e.g., disable out-of-range low
monitoring during fuel cut conditions).  To do so, the manufacturer must
demonstrate via data or engineering analyses that a properly functioning
sensor cannot be distinguished from a malfunctioning sensor and that the
disablement interval is limited only to that necessary for avoiding
false detection.

Secondary exhaust gas sensor monitoring conditions.

The manufacturer must define monitoring conditions for malfunctions
identified in paragraphs (h)(8)(iii)(A) through (h)(8)(iii)(C) of this
section in accordance with paragraphs (c) and  (d) of this section.

Except as provided for in paragraph (h)(8)(vi)(C) of this section,
monitoring for malfunctions identified in paragraphs (h)(8)(iii)(D) and
(h)(8)(iii)(E) of this section must be conducted continuously.

The manufacturer may disable continuous secondary exhaust gas sensor
monitoring when a secondary exhaust gas sensor malfunction cannot be
distinguished from other effects (e.g., disable out-of-range low
monitoring during fuel cut conditions).  To do so, the manufacturer must
demonstrate via data or engineering analyses that a properly functioning
sensor cannot be distinguished from a malfunctioning sensor and that the
disablement interval is limited only to that necessary for avoiding
false detection.

Exhaust gas sensor heater monitoring conditions.

The manufacturer must define monitoring conditions for malfunctions
identified in paragraph (h)(8)(iv)(A) of this section in accordance with
paragraphs (c) and  (d) of this section.

Monitoring for malfunctions identified in paragraph (h)(8)(iv)(B) of
this section must be conducted continuously.

Exhaust gas sensor MIL activation and DTC storage. The MIL must activate
and DTCs must be stored according to the provisions of paragraph (b) of
this section.

(h)(9) VVT system

Variable valve timing (VVT) system monitoring.

General. The OBD system must monitor the VVT system on engines so
equipped for target error and slow response malfunctions.  The
individual electronic components (e.g., actuators, valves, sensors) that
are used in the VVT system must be monitored in accordance with the
comprehensive components requirements in paragraph (i)(3) of this
section.

VVT system malfunction criteria.

VVT system target error. The OBD system must detect a malfunction prior
to any failure or deterioration in the capability of the VVT system to
achieve the commanded valve timing and/or control within a crank angle
and/or lift tolerance that would cause an engine’s emissions to exceed
the emission thresholds for “other monitors” as shown in Table 2 of
this paragraph (h).

VVT slow response. The OBD system must detect a malfunction prior to any
failure or deterioration in the capability of the VVT system to achieve
the commanded valve timing and/or control within a
manufacturer-specified time that would cause an engine’s emissions to
exceed the emission thresholds for “other monitors” as shown in
Table 2 of this paragraph (h).

For engines in which no failure or deterioration of the VVT system could
result in an engine’s emissions exceeding the applicable emissions
thresholds of paragraphs (h)(9)(ii)(A) and (h)(9)(ii)(B) of this
paragraph (h), the OBD system must detect a malfunction of the VVT
system when proper functional response of the system to computer
commands does not occur.

VVT system monitoring conditions. Manufacturers must define the
monitoring conditions for VVT system malfunctions identified in
paragraph (h)(9)(ii) of this section in accordance with paragraphs (c)
and (d) of this section, with the exception that monitoring must occur
every time the monitoring conditions are met during the drive cycle
rather than once per drive cycle as required in paragraph (c)(2) of this
section.  For purposes of tracking and reporting as required in
paragraph (d)(1) of this section, all monitors used to detect
malfunctions identified in paragraph (h)(9)(ii) of this section must be
tracked separately but reported as a single set of values as specified
in paragraph (e)(1)(iii) of this section.

VVT MIL activation and DTC storage. The MIL must activate and DTCs must
be stored according to the provisions of paragraph (b) of this section.

(i) Monitoring requirements for all engines

OBD monitoring requirements for all engines.

(i)(1) Cooling system

Engine cooling system monitoring.

General.

The OBD system must monitor the thermostat on engines so equipped for
proper operation.

The OBD system must monitor the engine coolant temperature (ECT) sensor
for electrical circuit continuity, out-of-range values, and rationality
malfunctions.

For engines that use a system other than the cooling system and ECT
sensor (e.g., oil temperature, cylinder head temperature) to determine
engine operating temperature for emission control purposes (e.g., to
modify spark or fuel injection timing or quantity), the manufacturer may
forego cooling system monitoring and instead monitor the components or
systems used in their approach.  To do so, the manufacturer must to
submit data and/or engineering analyses that demonstrate that their
monitoring plan is as reliable and effective as the monitoring required
in this paragraph (i)(1).

Malfunction criteria for the thermostat.

The OBD system must detect a thermostat malfunction if, within the
manufacturer specified time interval following engine start, any of the
following conditions occur:  the coolant temperature does not reach the
highest temperature required by the OBD system to enable other
diagnostics; and, the coolant temperature does not reach a warmed-up
temperature within 20 degrees Fahrenheit of the manufacturer’s nominal
thermostat regulating temperature.  For the second of these two
conditions, the manufacturer may use a lower temperature for this
criterion provided the manufacturer can demonstrate that the fuel, spark
timing, and/or other coolant temperature-based modification to the
engine control strategies would not cause an emissions increase greater
than or equal to 50 percent of any of the applicable emissions
standards.

The manufacturer may use alternative malfunction criteria to those of
paragraph (i)(1)(ii)(A) of this section and/or alternative monitoring
conditions to those of paragraph (i)(1)(iv) of this section that are a
function of temperature at engine start on engines that do not reach the
temperatures specified in the malfunction criteria when the thermostat
is functioning properly. To do so, the manufacturer is required to
submit data and/or engineering analyses that demonstrate that a properly
operating system does not reach the specified temperatures and that the
possibility is minimized for cooling system malfunctions to go
undetected thus disabling other OBD monitors.

The manufacturer may request Administrator approval to forego monitoring
of the thermostat if the manufacturer can demonstrate that a
malfunctioning thermostat cannot cause a measurable increase in
emissions during any reasonable driving condition nor cause any
disablement of other OBD monitors.

Malfunction criteria for the ECT sensor.

Circuit integrity. The OBD system must detect malfunctions of the ECT
sensor related to a lack of circuit continuity or out-of-range values.

Time to reach closed-loop/feedback enable temperature. The OBD system
must detect if, within the manufacturer specified time interval
following engine start, the ECT sensor does not achieve the highest
stabilized minimum temperature that is needed to initiate
closed-loop/feedback control of all affected emission control systems
(e.g., fuel system, EGR system).  The manufacturer specified time
interval must be a function of the engine coolant temperature and/or
intake air temperature at startup.  The manufacturer time interval must
be supported by data and/or engineering analyses demonstrating that it
provides robust monitoring and minimizes the likelihood of other OBD
monitors being disabled. The manufacturer may forego the requirements of
this paragraph (i)(1)(iii)(B) provided the manufacturer does not use
engine coolant temperature or the ECT sensor to enable
closed-loop/feedback control of any emission control systems.

Stuck in range below the highest minimum enable temperature. To the
extent feasible when using all available information, the OBD system
must detect a malfunction if the ECT sensor inappropriately indicates a
temperature below the highest minimum enable temperature required by the
OBD system to enable other monitors (e.g., an OBD system that requires
ECT to be greater than 140 degrees Fahrenheit to enable a diagnostic
must detect malfunctions that cause the ECT sensor to inappropriately
indicate a temperature below 140 degrees Fahrenheit).  The manufacturer
may forego this requirement for temperature regions in which the
monitors required under paragraphs (i)(1)(ii) or (i)(1)(iii)(B) of this
section will detect ECT sensor malfunctions as defined in this paragraph
(i)(1)(iii)(C).

Stuck in range above the lowest maximum enable temperature. The OBD
system must detect a malfunction if the ECT sensor inappropriately
indicates a temperature above the lowest maximum enable temperature
required by the OBD system to enable other monitors (e.g., an OBD system
that requires an engine coolant temperature less than 90 degrees
Fahrenheit at startup prior to enabling an OBD monitor must detect
malfunctions that cause the ECT sensor to indicate inappropriately a
temperature above 90 degrees Fahrenheit).  The manufacturer may forego
this requirement within temperature regions in which the monitors
required under paragraphs (i)(1)(ii), (i)(1)(iii)(B), and (i)(1)(iii)(C)
of this section will detect ECT sensor malfunctions as defined in this
paragraph (i)(1)(iii)(D) or in which the MIL will be activated according
to the provisions of paragraph (b)(2)(v) of this section. The
manufacturer may also forego this monitoring within temperature regions
where a temperature gauge on the instrument panel indicates a
temperature in the “red zone” (engine overheating zone) and displays
the same temperature information as used by the OBD system.

Monitoring conditions for the thermostat.

The manufacturer must define the monitoring conditions for malfunctions
identified in paragraph (i)(1)(ii)(A) of this section in accordance with
paragraph (c) of this section. Additionally, except as provided for in
paragraphs (i)(1)(iv)(B) and (i)(1)(iv)(C) of this section, monitoring
for malfunctions identified in paragraph (i)(1)(ii)(A) of this section
must be conducted once per drive cycle on every drive cycle in which the
ECT sensor indicates, at engine start, a temperature lower than the
temperature established as the malfunction criteria in paragraph
(i)(1)(ii)(A) of this section.

The manufacturer may disable thermostat monitoring at ambient engine
start temperatures below 20 degrees Fahrenheit.

The manufacturer may request Administrator approval to suspend or
disable thermostat monitoring if the engine is subjected to conditions
that could lead to false diagnosis. To do so, the manufacturer must
submit data and/or engineering analyses that demonstrate that the
suspension or disablement is necessary.  In general, the manufacturer
will not be allowed to suspend or disable the thermostat monitor on
engine starts where the engine coolant temperature at engine start is
more than 35 degrees Fahrenheit lower than the thermostat malfunction
threshold temperature determined under paragraph (i)(1)(ii)(A) of this
paragraph (i)(1).

Monitoring conditions for the ECT sensor.

Except as provided for in paragraph (i)(1)(v)(E) of this section, the
OBD system must monitor continuously for malfunctions identified in
paragraph (i)(1)(iii)(A) of this section (i.e., circuit integrity and
out-of-range).

The manufacturer must define the monitoring conditions for malfunctions
identified in paragraph (i)(1)(iii)(B) of this section in accordance
with paragraph (c) of this section.  Additionally, except as provided
for in paragraph (i)(1)(v)(D) of this section, monitoring for
malfunctions identified in paragraph (i)(1)(iii)(B) of this section must
be conducted once per drive cycle on every drive cycle in which the ECT
sensor indicates a temperature lower than the closed-loop enable
temperature at engine start (i.e., all engine start temperatures greater
than the ECT sensor out-of-range low temperature and less than the
closed-loop enable temperature).

The manufacturer must define the monitoring conditions for malfunctions
identified in paragraphs (i)(1)(iii)(C) and (i)(1)(iii)(D) of this
section in accordance with paragraphs (c) and (d) of this section.

The manufacturer may suspend or delay the monitor for the time to reach
closed-loop enable temperature if the engine is subjected to conditions
that could lead to false diagnosis (e.g., vehicle operation at idle for
more than 50 to 75 percent of the warm-up time).

The manufacturer may request Administrator approval to disable
continuous ECT sensor monitoring when an ECT sensor malfunction cannot
be distinguished from other effects.  To do so, the manufacturer must
submit data and/or engineering analyses that demonstrate a properly
functioning sensor cannot be distinguished from a malfunctioning sensor
and that the disablement interval is limited only to that necessary for
avoiding false detection.

Engine cooling system MIL activation and DTC storage. The MIL must
activate and DTCs must be stored according to the provisions of
paragraph (b) of this section.

(i)(2) Crankcase ventilation system

Crankcase ventilation (CV) system monitoring.

General. The OBD system must monitor the CV system on engines so
equipped for system integrity.  Engines not required to be equipped with
CV systems are exempt from monitoring the CV system.  For diesel
engines, the manufacturer must submit a plan for Administrator prior to
OBD certification. That plan must include descriptions of the monitoring
strategy, malfunction criteria, and monitoring conditions for CV system
monitoring.  The plan must demonstrate that the CV system monitor is of
equivalent effectiveness, to the extent feasible, to the malfunction
criteria and the monitoring conditions of this paragraph (i)(2).

Crankcase ventilation system malfunction criteria.

For the purposes of this paragraph (i)(2), “CV system” is defined as
any form of crankcase ventilation system, regardless of whether it
utilizes positive pressure.  “CV valve” is defined as any form of
valve or orifice used to restrict or control crankcase vapor flow.
Further, any additional external CV system tubing or hoses used to
equalize crankcase pressure or to provide a ventilation path between
various areas of the engine (e.g., crankcase and valve cover) are
considered part of the CV system “between the crankcase and the CV
valve” and subject to the malfunction criteria in paragraph
(i)(2)(ii)(B) of this section.

Except as provided for in paragraphs (i)(2)(ii)(C) through (i)(2)(ii)(E)
of this section, the OBD system must detect a malfunction of the CV
system when a disconnection of the system occurs between either the
crankcase and the CV valve, or between the CV valve and the intake
manifold.

The manufacturer may forego monitoring for a disconnection between the
crankcase and the CV valve provided the CV system is designed such that
the CV valve is fastened directly to the crankcase such that it is
significantly more difficult to remove the CV valve from the crankcase
than to disconnect the line between the CV valve and the intake manifold
(taking aging effects into consideration).  To do so, the manufacturer
must be able to provide data and/or an engineering evaluation
demonstrating that the CV system is so designed.

The manufacturer may forego monitoring for a disconnection between the
crankcase and the CV valve provided the CV system is designed such that
it uses tubing connections between the CV valve and the crankcase that
are:  resistant to deterioration or accidental disconnection;
significantly more difficult to disconnect than is the line between the
CV valve and the intake manifold; and, not subject to disconnection per
the manufacturer’s repair procedures for any non-CV system repair. To
do so, the manufacturer must be able to provide data and/or engineering
evaluation demonstrating that the CV system is so designed.

The manufacturer may forego monitoring for a disconnection between the
CV valve and the intake manifold provided the CV system is designed such
that any disconnection either causes the engine to stall immediately
during idle operation, or is unlikely to occur due to a CV system design
that is integral to the induction system (e.g., machined passages rather
than tubing or hoses).  To do so, the manufacturer must be able to
provide data and/or an engineering evaluation demonstrating that the CV
system is so designed.

Crankcase ventilation system monitoring conditions. The manufacturer
must define the monitoring conditions for malfunctions identified in
paragraph (i)(2) of this section in accordance with paragraphs (c) and
(d) of this section.

Crankcase ventilation system MIL activation and DTC storage. The MIL
must activate and DTCs must be stored according to the provisions of
paragraph (b) of this section.  The stored DTC need not identify
specifically the CV system (e.g., a DTC for idle speed control or fuel
system monitoring can be stored) if the manufacturer can demonstrate
that additional monitoring hardware is necessary to make such an
identification and provided the manufacturer’s diagnostic and repair
procedures for the detected malfunction include directions to check the
integrity of the CV system.

(i)(3) Comprehensive components

Comprehensive component monitoring.

General. Except as provided for in paragraph (i)(4) of this section, the
OBD system must detect a malfunction of any electronic engine component
or system not otherwise described in paragraphs (g), (h), (i)(1), and
(i)(2) of this section that either provides input to (directly or
indirectly, such components may include the crank angle sensor, knock
sensor, throttle position sensor, cam position sensor, intake air
temperature sensor, boost pressure sensor, manifold pressure sensor,
mass air flow sensor, exhaust temperature sensor, exhaust pressure
sensor, fuel pressure sensor, fuel composition sensor of a flexible fuel
vehicle, etc.) or receives commands from (such components or systems may
include the idle speed control system, glow plug system, variable length
intake manifold runner systems, supercharger or turbocharger electronic
components, heated fuel preparation systems, the wait-to-start lamp on
diesel applications, the MIL, etc.) the onboard computer(s) and meets
either of the criteria described in paragraphs (i)(3)(i)(A) and/or
(i)(3)(i)(B) of this section.  Note that, for the purposes of this
paragraph (i)(3), “electronic engine component or system” does not
include components that are driven by the engine and are not related to
the control of the fueling, air handling, or emissions of the engine
(e.g., power take-off (PTO) components, air conditioning system
components, and power steering components).

It can affect emissions during any reasonable in-use driving condition.
The manufacturer must be able to provide emission data showing that the
component or system, when malfunctioning and installed on a suitable
test engine, does not have an emission effect.

It is used as part of the monitoring strategy for any other monitored
system or component.

Comprehensive component malfunction criteria for input components.

The OBD system must detect malfunctions of input components caused by a
lack of circuit continuity and out-of-range values. In addition, where
feasible, rationality checks must also be done and shall verify that a
sensor output is neither inappropriately high nor inappropriately low
(i.e., “two-sided” monitoring).

To the extent feasible, the OBD system must separately detect and store
different DTCs that distinguish rationality malfunctions from lack of
circuit continuity and out-of-range malfunctions.  For lack of circuit
continuity and out-of-range malfunctions, the OBD system must, to the
extent feasible, separately detect and store different DTCs for each
distinct malfunction (e.g., out-of-range low, out-of-range high, open
circuit).  The OBD system is not required to store separate DTCs for
lack of circuit continuity malfunctions that cannot be distinguished
from other out-of-range circuit malfunctions.

For input components that are used to activate alternative strategies
that can affect emissions (e.g., AECDs, engine shutdown systems), the
OBD system must conduct rationality checks to detect malfunctions that
cause the system to activate erroneously or deactivate the alternative
strategy.  To the extent feasible when using all available information,
the rationality check must detect a malfunction if the input component
inappropriately indicates a value that activates or deactivates the
alternative strategy.  For example, for an alternative strategy that
activates when the intake air temperature is greater than 120 degrees
Fahrenheit, the OBD system must detect malfunctions that cause the
intake air temperature sensor to indicate inappropriately a temperature
above 120 degrees Fahrenheit.

For engines that require precise alignment between the camshaft and the
crankshaft, the OBD system must monitor the crankshaft position
sensor(s) and camshaft position sensor(s) to verify proper alignment
between the camshaft and crankshaft in addition to monitoring the
sensors for circuit continuity and proper rationality.  Proper alignment
monitoring between a camshaft and a crankshaft is required only in cases
where both are equipped with position sensors.  For engines equipped
with VVT systems and a timing belt or chain, the OBD system must detect
a malfunction if the alignment between the camshaft and crankshaft is
off by one or more cam/crank sprocket cogs (e.g., the timing belt/chain
has slipped by one or more teeth/cogs).  If a manufacturer demonstrates
that a single tooth/cog misalignment cannot cause a measurable increase
in emissions during any reasonable driving condition, the OBD system
must detect a malfunction when the minimum number of teeth/cogs
misalignment has occurred that does cause a measurable emission
increase.

Comprehensive component malfunction criteria for output
components/systems.

The OBD system must detect a malfunction of an output component/system
when proper functional response does not occur in response to computer
commands.  If such a functional check is not feasible, the OBD system
must detect malfunctions of output components/systems caused by a lack
of circuit continuity or circuit malfunction (e.g., short to ground or
high voltage).  For output component lack of circuit continuity
malfunctions and circuit malfunctions, the OBD system is not required to
store different DTCs for each distinct malfunction (e.g., open circuit,
shorted low).  Manufacturers are not required to activate an output
component/system when it would not normally be active for the sole
purpose of performing a functional check of it as required in this
paragraph (i)(3).

For gasoline engines, the idle control system must be monitored for
proper functional response to computer commands. For gasoline engines
using monitoring strategies based on deviation from target idle speed, a
malfunction must be detected when either of the following conditions
occurs: the idle speed control system cannot achieve the target idle
speed within 200 revolutions per minute (rpm) above the target speed or
100 rpm below the target speed; or, the idle speed control system cannot
achieve the target idle speed within the smallest engine speed tolerance
range required by the OBD system to enable any other monitors.
Regarding the former of these conditions, the manufacturer may use
larger engine speed tolerances.  To do so, the manufacturer must be able
to provide data and/or engineering analyses that demonstrate that the
tolerances can be exceeded without a malfunction being present.

For diesel engines, the idle control system must be monitored for proper
functional response to computer commands. For diesel engines, a
malfunction must be detected when either of the following conditions
occurs: the idle fuel control system cannot achieve the target idle
speed or fuel injection quantity within +/-50 percent of the
manufacturer-specified fuel quantity and engine speed tolerances; or,
the idle fuel control system cannot achieve the target idle speed or
fueling quantity within the smallest engine speed or fueling quantity
tolerance range required by the OBD system to enable any other monitors.

Glow plugs/intake air heater systems must be monitored for proper
functional response to computer commands and for circuit continuity
malfunctions.  The glow plug/intake air heater circuit(s) must be
monitored for proper current and voltage drop.  The manufacturer may use
other monitoring strategies but must be able to provide data and/or
engineering analyses that demonstrate reliable and timely detection of
malfunctions.  The OBD system must also detect a malfunction when a
single glow plug no longer operates within the manufacturer’s
specified limits for normal operation.  If a manufacturer can
demonstrate that a single glow plug malfunction cannot cause a
measurable increase in emissions during any reasonable driving
condition, the OBD system must instead detect a malfunction when the
number of glow plugs needed to cause an emission increase is
malfunctioning.  To the extent feasible, the stored DTC must identify
the specific malfunctioning glow plug(s).

The wait-to-start lamp circuit and the MIL circuit must be monitored for
malfunctions that cause either lamp to fail to activate when commanded
to do so (e.g., burned out bulb).

Monitoring conditions for input components.

The OBD system must monitor input components continuously for
out-of-range values and circuit continuity. The manufacturer may disable
continuous monitoring for circuit continuity and out-of-range values
when a malfunction cannot be distinguished from other effects.  To do
so, the manufacturer must be able to provide data and/or engineering
analyses that demonstrate that a properly functioning input component
cannot be distinguished from a malfunctioning input component and that
the disablement interval is limited only to that necessary for avoiding
false malfunction detection.

For input component rationality checks (where applicable), the
manufacturer must define the monitoring conditions for detecting
malfunctions in accordance with paragraphs (c) and (d) of this section,
with the exception that rationality checks must occur every time the
monitoring conditions are met during the drive cycle rather than once
per drive cycle as required in paragraph (c)(2) of this section.

Monitoring conditions for output components/systems.

The OBD system must monitor output components/systems continuously for
circuit continuity and circuit malfunctions. The manufacturer may
disable continuous monitoring for circuit continuity and circuit
malfunctions when a malfunction cannot be distinguished from other
effects.  To do so, the manufacturer must be able to provide data and/or
engineering analyses that demonstrate that a properly functioning output
component/system cannot be distinguished from a malfunctioning one and
that the disablement interval is limited only to that necessary for
avoiding false malfunction detection.

For output component/system functional checks, the manufacturer must
define the monitoring conditions for detecting malfunctions in
accordance with paragraphs (c) and (d) of this section. Specifically for
the idle control system, the manufacturer must define the monitoring
conditions for detecting malfunctions in accordance with paragraphs (c)
and (d) of this section, with the exception that functional checks must
occur every time the monitoring conditions are met during the drive
cycle rather than once per drive cycle as required in paragraph (c)(2)
of this section.

Comprehensive component MIL activation and DTC storage.

Except as provided for in paragraphs (i)(3)(vi)(B) and (i)(3)(vi)(C) of
this section, the MIL must activate and DTCs must be stored according to
the provisions of paragraph (b) of this section.

The MIL need not be activated in conjunction with storing a MIL-on DTC
for any comprehensive component if: the component or system, when
malfunctioning, could not cause engine emissions to increase by 15
percent or more of the applicable FTP standard during any reasonable
driving condition; or, the component or system is not used as part of
the monitoring strategy for any other system or component that is
required to be monitored.

The MIL need not be activated if a malfunction has been detected in the
MIL circuit that prevents the MIL from activating (e.g., burned out bulb
or light-emitting diode, LED). Nonetheless, the electronic MIL status
(see paragraph (k)(4)(ii) of this section) must be reported as MIL
commanded-on and a MIL-on DTC must be stored.

(i)(4) Other emission control systems

Other emission control system monitoring.

General. For other emission control systems that are either not
addressed in paragraphs (g) through (i)(3) of this section (e.g.,
hydrocarbon traps, homogeneous charge compression ignition control
systems), or addressed in paragraph (i)(3) of this section but not
corrected or compensated for by an adaptive control system (e.g., swirl
control valves), the manufacturer must submit a plan for Administrator
approval of the monitoring strategy, malfunction criteria, and
monitoring conditions prior to introduction on a production engine.  The
plan must demonstrate the effectiveness of the monitoring strategy, the
malfunction criteria used, the monitoring conditions required by the
monitor, and, if applicable, the determination that the requirements of
paragraph (i)(4)(ii) of this section are satisfied.

For engines that use emission control systems that alter intake air flow
or cylinder charge characteristics by actuating valve(s), flap(s), etc.,
in the intake air delivery system (e.g., swirl control valve systems),
the manufacturer, in addition to meeting the requirements of paragraph
(i)(4)(i) of this section, may elect to have the OBD system monitor the
shaft to which all valves in one intake bank are physically attached
rather than performing a functional check of the intake air flow,
cylinder charge, or individual valve(s)/flap(s).  For non-metal shafts
or segmented shafts, the monitor must verify all shaft segments for
proper functional response (e.g., by verifying that the segment or
portion of the shaft farthest from the actuator functions properly).
For systems that have more than one shaft to operate valves in multiple
intake banks, the manufacturer is not required to add more than one set
of detection hardware (e.g., sensor, switch) per intake bank to meet
this requirement.

(i)(5) Exceptions to monitoring requirements

Exceptions to OBD monitoring requirements.

The Administrator may revise the PM filtering performance malfunction
criteria for DPFs to exclude detection of specific failure modes such as
partially melted substrates, if the most reliable monitoring method
developed requires it.

The manufacturer may disable an OBD system monitor at ambient engine
start temperatures below 20 degrees Fahrenheit (low ambient temperature
conditions may be determined based on intake air or engine coolant
temperature at engine start) or at elevations higher than 8,000 feet
above sea level.  To do so, the manufacturer must submit data and/or
engineering analyses that demonstrate that monitoring is unreliable
during the disable conditions.  A manufacturer may request that an OBD
system monitor be disabled at other ambient engine start temperatures by
submitting data and/or engineering analyses demonstrating that
misdiagnosis would occur at the given ambient temperatures due to their
effect on the component itself (e.g., component freezing).

The manufacturer may disable an OBD system monitor when the fuel level
is 15 percent or less of the nominal fuel tank capacity for those
monitors that can be affected by low fuel level or running out of fuel
(e.g., misfire detection).  To do so, the manufacturer must submit data
and/or engineering analyses that demonstrate that monitoring at the
given fuel levels is unreliable, and that the OBD system is still able
to detect a malfunction if the component(s) used to determine fuel level
indicates erroneously a fuel level that causes the disablement.

The manufacturer may disable OBD monitors that can be affected by engine
battery or system voltage levels.

 For an OBD monitor affected by low vehicle battery or system voltages,
manufacturers may disable monitoring when the battery or system voltage
is below 11.0 Volts.  The manufacturer may use a voltage threshold
higher than 11.0 Volts to disable monitors but must submit data and/or
engineering analyses that demonstrate that monitoring at those voltages
is unreliable and that either operation of a vehicle below the
disablement criteria for extended periods of time is unlikely or the OBD
system monitors the battery or system voltage and will detect a
malfunction at the voltage used to disable other monitors.

For an OBD monitor affected by high engine battery or system voltages,
the manufacturer may disable monitoring when the battery or system
voltage exceeds a manufacturer-defined voltage.  To do so, the
manufacturer must submit data and/or engineering analyses that
demonstrate that monitoring above the manufacturer-defined voltage is
unreliable and that either the electrical charging system/alternator
warning light will be activated (or voltage gauge would be in the “red
zone”) or the OBD system monitors the battery or system voltage and
will detect a malfunction at the voltage used to disable other monitors.

The manufacturer may also disable affected OBD monitors in systems
designed to accommodate the installation of power take off (PTO) units
provided monitors are disabled only while the PTO unit is active and the
OBD readiness status (see paragraph (k)(4)(i) of this section) is
cleared by the onboard computer (i.e., all monitors set to indicate
“not complete” or “not ready”) while the PTO unit is activated.
If monitors are so disabled and when the disablement ends, the readiness
status may be restored to its state prior to PTO activation.

(i)(6) Feedback control system

Feedback control system monitoring. If the engine is equipped with
feedback control of any of the systems covered in paragraphs (g), (h)
and (i) of this section, then the OBD system must detect as malfunctions
the conditions specified in this paragraph (i)(6) for each of the
individual feedback controls.

The OBD system must detect when the system fails to begin feedback
control within a manufacturer specified time interval.

When any malfunction or deterioration causes open loop or limp-home
operation.

When feedback control has used up all of the adjustment allowed by the
manufacturer.

A manufacturer may temporarily disable monitoring for malfunctions
specified in paragraph (i)(6)(iii) of this section during conditions
that the specific monitor cannot distinguish robustly between a
malfunctioning system and a properly operating system.  To do so, the
manufacturer is required to submit data and/or engineering analyses
demonstrating that the individual feedback control system, when
operating as designed on an engine with all emission controls working
properly, routinely operates during these conditions while having used
up all of the adjustment allowed by the manufacturer.   In lieu of
detecting, with a system specific monitor, the malfunctions specified in
paragraphs (i)(6)(i) and (i)(6)(ii) of this section the OBD system may
monitor the individual parameters or components that are used as inputs
for individual feedback control systems provided that the monitors
detect all malfunctions that meet the criteria of paragraphs (i)(6)(i)
and (i)(6)(ii) of this section.

(j) Production evaluation testing

Production evaluation testing.

[Reserved.]

Verification of monitoring requirements.

Within either the first six months of the start of engine production or
the first three months of the start of vehicle production, whichever is
later, the manufacturer must conduct a complete evaluation of the OBD
system of one or more production vehicles (test vehicles) and submit the
results of the evaluation to the Administrator.

Selection of test vehicles.

For each engine selected for monitoring system demonstration in
paragraph (l) of this section, the manufacturer must evaluate one
production vehicle equipped with an engine from the same engine family
and rating as the demonstration engine. The vehicle selection must be
approved by the Administrator.

If the manufacturer is required to test more than one test vehicle, the
manufacturer may test an engine in lieu of a vehicle for all but one of
the required test vehicles.

The requirement for submittal of data from one or more of the test
vehicles may be waived if data have been submitted previously for all of
the engine ratings and variants.

Evaluation requirements.

The evaluation must demonstrate the ability of the OBD system on the
selected test vehicle to detect a malfunction, activate the MIL, and,
where applicable, store an appropriate DTC readable by a scan tool when
a malfunction is present and the monitoring conditions have been
satisfied for each individual monitor required by this section.

The evaluation must verify that the malfunction of any component used to
enable another OBD monitor but that does not itself result in MIL
activation (e.g., fuel level sensor) will not inhibit the ability of
other OBD monitors to detect malfunctions properly.

The evaluation must verify that the software used to track the numerator
and denominator for the purpose of determining in-use monitoring
frequency increments as required by paragraph (d)(2) of this section.

Malfunctions may be implanted mechanically or simulated electronically,
but internal onboard computer hardware or software changes shall not be
used to simulate malfunctions.  For monitors that are required to
indicate a malfunction before emissions exceed an emission threshold,
manufacturers are not required to use malfunctioning components/systems
set exactly at their malfunction criteria limits.  Emission testing is
not required to confirm that the malfunction is detected before the
appropriate emission thresholds are exceeded.

The manufacturer must submit a proposed test plan for approval prior to
performing evaluation testing.  The test plan must identify the method
used to induce a malfunction for each monitor.

If the demonstration of a specific monitor cannot be reasonably
performed without causing physical damage to the test vehicle (e.g.,
onboard computer internal circuit malfunctions), the manufacturer may
omit the specific demonstration.

For evaluation of test vehicles selected in accordance with paragraph
(j)(2)(ii) of this section, the manufacturer is not required to
demonstrate monitors that were demonstrated prior to certification as
required in paragraph (l) of this section.

The manufacturer must submit a report of the results of all testing
conducted as required by paragraph (j)(2) of this section. The report
must identify the method used to induce a malfunction in each monitor,
the MIL activation status, and the DTC(s) stored.

Verification of in-use monitoring performance ratios.

The manufacturer must collect and report in-use monitoring performance
data representative of production vehicles (i.e., engine rating and
chassis application combination).  The manufacturer must collect and
report the data to the Administrator within 12 months after the first
production vehicle was first introduced into commerce.

The manufacturer must separate production vehicles into the monitoring
performance groups and submit data that represents each of these groups.
The groups shall be based on the following criteria:

Emission control system architecture.  All engines that use the same or
similar emissions control system architecture (e.g., EGR with DPF and
SCR; EGR with DPF and NOx adsorber; EGR with DPF-only) and associated
monitoring system would be in the same emission architecture category.

Vehicle application type. Within an emission architecture category,
engines shall be separated into one of three vehicle application types:
engines intended primarily for line-haul chassis applications, engines
intended primarily for urban delivery chassis applications, and all
other engines.

The manufacturer may use an alternative grouping method to collect
representative data.  To do so, the manufacturer must show that the
alternative groups include production vehicles using similar emission
controls, OBD strategies, monitoring condition calibrations, and vehicle
application driving/usage patterns such that they are expected to have
similar in-use monitoring performance. The manufacturer will still be
required to submit one set of data for each of the alternative groups.

For each monitoring performance group, the data must include all of the
in-use performance tracking data (i.e., all numerators, denominators,
the general denominator, and the ignition cycle counter), the date the
data were collected, the odometer reading, the VIN, and the calibration
ID.

The manufacturer must submit a plan to the Administrator that details
the types of production vehicles in each monitoring performance group,
the number of vehicles per group to be sampled, the sampling method, the
timeline to collect the data, and the reporting format. The plan must
provide for effective collection of data from, at least, 15 vehicles per
monitoring performance group and provide for data that represent a broad
range of temperature conditions. The plan shall not, by design, exclude
or include specific vehicles in an attempt to collect data only from
vehicles expected to have the highest in-use performance ratios.

The 12 month deadline for reporting may be extended to 18 months if the
manufacturer can show that the delay is justified.  In such a case, an
interim report of progress to date must be submitted within the 12 month
deadline.

(k) Standardization requirements

Standardization requirements.

Reference materials. The OBD system must 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 §86.1:

SAE material. Copies of these materials may be obtained from the Society
of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA
15096–0001.

SAE J1930 “Electrical/Electronic Systems Diagnostic Terms,
Definitions, Abbreviations, and Acronyms – Equivalent to ISO/TR
15031-2:April 30, 2002,” April 2002.

SAE J1939 “Recommended Practice for a Serial Control and
Communications Vehicle Network” and the associated subparts included
in SAE HS-1939, “Truck and Bus Control and Communications Network
Standards Manual,” 2006 Edition.

[Reserved.]

SAE J1978 “OBD II Scan Tool – Equivalent to ISO/DIS 15031-4:
December 14, 2001,” April 2002.

SAE J1979 “E/E Diagnostic Test Modes – Equivalent to ISO/DIS
15031-5:April 30, 2002,” April 2002.

SAE J2012 “Diagnostic Trouble Code Definitions – Equivalent to
ISO/DIS 15031-6:April 30, 2002,” April 2002.

SAE J2403 “Medium/Heavy-Duty E/E Systems Diagnosis Nomenclature,”
August 2004.

SAE J2534 “Recommended Practice for Pass-Thru Vehicle
Reprogramming,” February 2002.

ISO materials. Copies of these materials may be obtained from the
International Organization for Standardization, Case Postale 56,
CH–1211 Geneva 20, Switzerland.

ISO 15765-4:2001 “Road Vehicles-Diagnostics on Controller Area Network
(CAN) - Part 4: Requirements for emission-related systems,” December
2001.

The manufacturer defined data link connector must be accessible to a
trained service technician.

[Reserved.]

Required emission related functions. The following functions must be
implemented and must be accessible by, at a minimum, a manufacturer scan
tool:

Ready status. The OBD system must indicate “complete” or “not
complete” for each of the installed monitored components and systems
identified in paragraphs (g), (h) with the exception of (h)(4), and
(i)(3) of this section. All components or systems identified in
paragraphs (h)(1), (h)(2), or (i)(3) of this section that are monitored
continuously must always indicate “complete.” Components or systems
that are not subject to being monitored continuously must immediately
indicate “complete” upon the respective monitor(s) being executed
fully and determining that the component or system is not
malfunctioning.  A component or system must also indicate “complete”
if, after the requisite number of decisions necessary for determining
MIL status has been executed fully, the monitor indicates a malfunction
of the component or system.  The status for each of the monitored
components or systems must indicate “not complete” whenever
diagnostic memory has been cleared or erased by a means other than that
allowed in paragraph (b) of this section.  Normal vehicle shut down
(i.e., key-off/engine-off) shall not cause the status to indicate “not
complete.”

The manufacturer may request that the ready status for a monitor be set
to indicate “complete” without the monitor having completed if
monitoring is disabled for a multiple number of drive cycles due to the
continued presence of extreme operating conditions (e.g., cold ambient
temperatures, high altitudes).  Any such request must specify the
conditions for monitoring system disablement and the number of drive
cycles that would pass without monitor completion before ready status
would be indicated as “complete.”

For the evaporative system monitor, the ready status must be set in
accordance with this paragraph (k)(4)(i) when both the functional check
of the purge valve and, if applicable, the leak detection monitor of the
hole size specified in paragraph  (h)(7)(ii)(B) of this section indicate
that they are complete.

If the manufacturer elects to indicate ready status through the MIL in
the key-on/engine-off position as provided for in paragraph (b)(1)(iii)
of this section, the ready status must be indicated in the following
manner: If the ready status for all monitored components or systems is
“complete,” the MIL shall remain continuously activated in the
key-on/engine-off position for at least 10-20 seconds.  If the ready
status for one or more of the monitored components or systems is “not
complete,” after at least 5 seconds of operation in the
key-on/engine-off position with the MIL activated continuously, the MIL
shall blink once per second for 5-10 seconds.  The data stream value for
MIL status as required in paragraph (k)(4)(ii) of this section must
indicate “commanded off” during this sequence unless the MIL has
also been “commanded on” for a detected malfunction.

Data stream. The following signals must be made available on demand
through the data link connector.  The actual signal value must always be
used instead of a limp home value.

For gasoline engines.

Calculated load value, engine coolant temperature, engine speed, vehicle
speed, and time elapsed since engine start.

Absolute load, fuel level (if used to enable or disable any other
monitors), barometric pressure (directly measured or estimated), engine
control module system voltage, and commanded equivalence ratio.

Number of stored MIL-on DTCs, catalyst temperature (if directly measured
or estimated for purposes of enabling the catalyst monitor(s)), monitor
status (i.e., disabled for the rest of this drive cycle, complete this
drive cycle, or not complete this drive cycle) since last engine
shut-off for each monitor used for ready status, distance traveled (or
engine run time for engines not using vehicle speed information) while
MIL activated, distance traveled (or engine run time for engines not
using vehicle speed information) since DTC memory last erased, and
number of warm-up cycles since DTC memory last erased, OBD requirements
to which the engine is certified (e.g., California OBD, EPA OBD,
European OBD, non-OBD) and MIL status (i.e., commanded-on or
commanded-off).

For diesel engines.

Calculated load (engine torque as a percentage of maximum torque
available at the current engine speed), driver’s demand engine torque
(as a percentage of maximum engine torque), actual engine torque (as a
percentage of maximum engine torque), reference engine maximum torque,
reference maximum engine torque as a function of engine speed (suspect
parameter numbers (SPN) 539 through 543 defined by SAE J1939 within
parameter group number (PGN) 65251 for engine configuration), engine
coolant temperature, engine oil temperature (if used for emission
control or any OBD monitors), engine speed, and time elapsed since
engine start.

Fuel level (if used to enable or disable any other monitors), vehicle
speed (if used for emission control or any OBD monitors), barometric
pressure (directly measured or estimated), and engine control module
system voltage.

Number of stored MIL-on DTCs, monitor status (i.e., disabled for the
rest of this drive cycle, complete this drive cycle, or not complete
this drive cycle) since last engine shut-off for each monitor used for
ready status, distance traveled (or engine run time for engines not
using vehicle speed information) while MIL activated, distance traveled
(or engine run time for engines not using vehicle speed information)
since DTC memory last erased, number of warm-up cycles since DTC memory
last erased, OBD requirements to which the engine is certified (e.g.,
California OBD, EPA OBD, European OBD, non-OBD), and MIL status (i.e.,
commanded-on or commanded-off).

NOx NTE control area status (i.e., inside control area, outside control
area, inside manufacturer-specific NOx NTE carve-out area, or deficiency
active area) and PM NTE control area status (i.e., inside control area,
outside control area, inside manufacturer-specific PM NTE carve-out
area, or deficiency active area).

For purposes of the calculated load and torque parameters in paragraph
(k)(4)(ii)(B)(1) of this section, manufacturers must report the most
accurate values that are calculated within the applicable electronic
control unit (e.g., the engine control module).  Most accurate, in this
context, must be of sufficient accuracy, resolution, and filtering to be
used for the purposes of in-use emission testing with the engine still
in a vehicle (e.g., using portable emission measurement equipment).

For all engines so equipped.

Absolute throttle position, relative throttle position, fuel control
system status (e.g., open loop, closed loop), fuel trim, fuel pressure,
ignition timing advance, fuel injection timing, intake air/manifold
temperature, engine intercooler temperature, manifold absolute pressure,
air flow rate from mass air flow sensor, secondary air status (upstream,
downstream, or atmosphere), ambient air temperature, commanded purge
valve duty cycle/position, commanded EGR valve duty cycle/position,
actual EGR valve duty cycle/position, EGR error between actual and
commanded, PTO status (active or not active), redundant absolute
throttle position (for electronic throttle or other systems that utilize
two or more sensors), absolute pedal position, redundant absolute pedal
position, commanded throttle motor position, fuel rate, boost pressure,
commanded/target boost pressure, turbo inlet air temperature, fuel rail
pressure, commanded fuel rail pressure, DPF inlet pressure, DPF inlet
temperature, DPF outlet pressure, DPF outlet temperature, DPF delta
pressure, exhaust pressure sensor output, exhaust gas temperature sensor
output, injection control pressure, commanded injection control
pressure, turbocharger/turbine speed, variable geometry turbo position,
commanded variable geometry turbo position, turbocharger compressor
inlet temperature, turbocharger compressor inlet pressure, turbocharger
turbine inlet temperature, turbocharger turbine outlet temperature,
waste gate valve position, and glow plug lamp status.

Oxygen sensor output, air/fuel ratio sensor output, NOx sensor output,
and evaporative system vapor pressure.

Freeze frame.

“Freeze frame” information required to be stored pursuant to
paragraphs (b)(2)(iv), (h)(1)(iv)(D), and (h)(2)(vi) of this section
must be made available on demand through the data link connector.

“Freeze frame” conditions must include the DTC that caused the data
to be stored along with all of the signals required in paragraphs
(k)(4)(ii)(A)(1) or (k)(4)(ii)(B)(1) of this section.  Freeze frame
conditions must also include all of the signals required on the engine
in paragraphs (k)(4)(ii)(A)(2) and (k)(4)(ii)(B)(2) of this section,
and paragraph (k)(4)(ii)(C)(1) of this section that are used for
diagnostic or control purposes in the specific monitor or
emission-critical powertrain control unit that stored the DTC.

Only one frame of data is required to be recorded.  The manufacturer may
choose to store additional frames provided that at least the required
frame can be read by, at a minimum, a manufacturer scan tool.

Diagnostic trouble codes.

For all monitored components and systems, any stored pending, MIL-on,
and previous-MIL-on DTCs must be made available through the diagnostic
connector.

The stored DTC must, to the extent possible, pinpoint the probable cause
of the malfunction or potential malfunction. To the extent feasible, the
manufacturer must use separate DTCs for every monitor where the monitor
and repair procedure or probable cause of the malfunction is different.
In general, rationality and functional checks must use different DTCs
than the respective circuit integrity checks. Additionally, input
component circuit integrity checks must use different DTCs for distinct
malfunctions (e.g., out-of-range low, out-of-range high, open circuit).

The manufacturer must use appropriate standard-defined DTCs whenever
possible.  With Administrator approval, the manufacturer may use
manufacturer-defined DTCs in accordance with the applicable standard’s
specifications.  To do so, the manufacturer must be able to show a lack
of available standard-defined DTCs, uniqueness of the monitor or
monitored component, expected future usage of the monitor or component,
and estimated usefulness in providing additional diagnostic and repair
information to service technicians.  Manufacturer-defined DTCs must be
used in a consistent manner (i.e., the same DTC shall not be used to
represent two different failure modes) across a manufacturer’s entire
product line.

A pending or MIL-on DTC (as required in paragraphs (g) through (i) of
this section) must be stored and available to, at a minimum, a
manufacturer scan tool within 10 seconds after a monitor has determined
that a malfunction or potential malfunction has occurred. A permanent
DTC must be stored and available to, at a minimum, a manufacturer scan
tool no later than the end of an ignition cycle in which the
corresponding MIL-on DTC that caused MIL activation has been stored.

Pending DTCs for all components and systems (including those monitored
continuously and non-continuously) must be made available through the
diagnostic connector. A manufacturer using alternative statistical
protocols for MIL activation as allowed in paragraph (b)(2)(iii) of this
section must submit the details of their protocol for setting pending
DTCs. The protocol must be, overall, equivalent to the requirements of
this paragraph (k)(4)(iv)(E) and provide service technicians with a
quick and accurate indication of a potential malfunction.

Permanent DTC for all components and systems must be made available
through the diagnostic connector in a format that distinguishes
permanent DTCs from pending DTCs, MIL-on DTCs, and previous-MIL-on DTCs.
A MIL-on DTC must be stored as a permanent DTC no later than the end of
the ignition cycle and subsequently at all times that the MIL-on DTC is
commanding the MIL on. Permanent DTCs must be stored in non-volatile
random access memory (NVRAM) and shall not be erasable by any scan tool
command or by disconnecting power to the on-board computer. Permanent
DTCs must be erasable if the engine control module is reprogrammed and
the ready status described in paragraph (k)(4)(i) of this section for
all monitored components and systems are set to “not complete.” The
OBD system must have the ability to store a minimum of four current
MIL-on DTCs as permanent DTCs in NVRAM.  If the number of MIL-on DTCs
currently commanding activation of the MIL exceeds the maximum number of
permanent DTCs that can be stored, the OBD system must store the
earliest detected MIL-on DTC as permanent DTC.  If additional MIL-on
DTCs are stored when the maximum number of permanent DTCs is already
stored in NVRAM, the OBD system shall not replace any existing permanent
DTC with the additional MIL-on DTCs.

Test results.

Except as provided for in paragraph (k)(4)(v)(G) of this section, for
all monitored components and systems identified in paragraphs (g) and
(h) of this section, results of the most recent monitoring of the
components and systems and the test limits established for monitoring
the respective components and systems must be stored and available
through the data link.

The test results must be reported such that properly functioning
components and systems (e.g., “passing” systems) do not store test
values outside of the established test limits.  Test limits must include
both minimum and maximum acceptable values and must be defined so that a
test result equal to either test limit is a “passing” value, not a
“failing” value.

[Reserved.]

The test results must be stored until updated by a more recent valid
test result or the DTC memory of the OBD system computer is cleared.
Upon DTC memory being cleared, test results reported for monitors that
have not yet completed with valid test results since the last time the
fault memory was cleared must report values of zero for the test result
and test limits.

All test results and test limits must always be reported and the test
results must be stored until updated by a more recent valid test result
or the DTC memory of the OBD system computer is cleared.

The OBD system must store and report unique test results for each
separate monitor.

The requirements of this paragraph (k)(4)(v) do not apply to continuous
fuel system monitoring, cold start emission reduction strategy
monitoring, and continuous circuit monitoring.

Software calibration identification (CAL ID). On all engines, a single
software calibration identification number (CAL ID) for each monitor or
emission critical control unit(s) must be made available through the
data link connector.  A unique CAL ID must be used for every
emission-related calibration and/or software set having at least one bit
of different data from any other emission-related calibration and/or
software set.  Control units coded with multiple emission or diagnostic
calibrations and/or software sets must indicate a unique CAL ID for each
variant in a manner that enables an off-board device to determine which
variant is being used by the vehicle.  Control units that use a strategy
that will result in MIL activation if the incorrect variant is used
(e.g., control units that contain variants for manual and automatic
transmissions but will activate the MIL if the selected variant does not
match the type of transmission mated to the engine) are not required to
use unique CAL IDs.

Software calibration verification number (CVN).

All engines must use an algorithm to calculate a single calibration
verification number (CVN) that verifies the on-board computer software
integrity for each monitor or emission critical control unit that is
electronically reprogrammable.  The CVN must be made available through
the data link connector.  The CVN must indicate whether the
emission-related software and/or calibration data are valid and
applicable for the given vehicle and CAL ID.

The CVN algorithm used to calculate the CVN must be of sufficient
complexity that the same CVN is difficult to achieve with modified
calibration values.

The CVN must be calculated at least once per drive cycle and stored
until the CVN is subsequently updated.  Except for immediately after a
reprogramming event or a non-volatile memory clear or for the first 30
seconds of engine operation after a volatile memory clear or battery
disconnect, the stored value must be made available through the data
link connector to, at a minimum, a manufacturer scan tool.  The stored
CVN value shall not be erased when DTC memory is erased or during normal
vehicle shut down (i.e., key-off/engine-off).

[Reserved.]

Vehicle identification number (VIN).

All vehicles must have the vehicle identification number (VIN) available
through the data link connector to, at a minimum, a manufacturer scan
tool.  Only one electronic control unit per vehicle may report the VIN
to a scan tool.

If the VIN is reprogrammable, all emission-related diagnostic
information identified in paragraph (k)(4)(ix)(A) of this section must
be erased in conjunction with reprogramming of the VIN.

Erasure of diagnostic information.

For purposes of this paragraph (k)(4)(ix), “emission-related
diagnostic information” includes all of the following:  ready status
as required by paragraph (k)(4)(i) of this section; data stream
information as required by paragraph (k)(4)(ii) of this section
including the number of stored MIL-on DTCs, distance traveled while MIL
activated, number of warm-up cycles since DTC memory last erased, and
distance traveled since DTC memory last erased; freeze frame information
as required by paragraph (k)(4)(iii) of this section; pending, MIL-on,
and previous-MIL-on DTCs as required by paragraph (k)(4)(iv) of this
section; and, test results as required by paragraph (k)(4)(v) of this
section.

For all engines, the emission-related diagnostic information must be
erased if commanded by any scan tool and may be erased if the power to
the on-board computer is disconnected.  If any of the emission-related
diagnostic information is commanded to be erased by any scan tool, all
emission-related diagnostic information must be erased from all
diagnostic or emission critical control units.  The OBD system shall not
allow a scan tool to erase a subset of the emission-related diagnostic
information (e.g., the OBD system shall not allow a scan tool to erase
only one of three stored DTCs or only information from one control unit
without erasing information from the other control unit(s)).

In-use performance ratio tracking requirements.

For each monitor required in paragraphs (g) through (i) of this section
to separately report an in-use performance ratio, manufacturers must
implement software algorithms to report a numerator and denominator.

For the numerator, denominator, general denominator, and ignition cycle
counters required by paragraph (e) of this section, the following
numerical value specifications apply:

Each number shall have a minimum value of zero and a maximum value of
65,535 with a resolution of one.

Each number shall be reset to zero only when a non-volatile random
access memory (NVRAM) reset occurs (e.g., reprogramming event) or, if
the numbers are stored in keep-alive memory (KAM), when KAM is lost due
to an interruption in electrical power to the control unit (e.g.,
battery disconnect).  Numbers shall not be reset to zero under any other
circumstances including when a scan tool command to clear DTCs or reset
KAM is received.

To avoid overflow problems, if either the numerator or denominator for a
specific component reaches the maximum value of 65,535 ±2, both numbers
shall be divided by two before either is incremented again.

To avoid overflow problems, if the ignition cycle counter reaches the
maximum value of 65,535 ±2, the ignition cycle counter shall rollover
and increment to zero on the next ignition cycle.

To avoid overflow problems, if the general denominator reaches the
maximum value of 65,535 ±2, the general denominator shall rollover and
increment to zero on the next drive cycle that meets the general
denominator definition.

If a vehicle is not equipped with a component (e.g., oxygen sensor bank
2, secondary air system), the corresponding numerator and denominator
for that specific component shall always be reported as zero.

For the ratio required by paragraph (e) of this section, the following
numerical value specifications apply:

The ratio shall have a minimum value of zero and a maximum value of
7.99527 with a resolution of 0.000122.

The ratio for a specific component shall be considered to be zero
whenever the corresponding numerator is equal to zero and the
corresponding denominator is not zero.

The ratio for a specific component shall be considered to be the maximum
value of 7.99527 if the corresponding denominator is zero or if the
actual value of the numerator divided by the denominator exceeds the
maximum value of 7.99527.

Engine run time tracking requirements.

For all gasoline and diesel engines, the manufacturer must implement
software algorithms to track and report individually the amount of time
the engine has been operated in the following conditions:

Total engine run time.

Total idle run time (with “idle” defined as accelerator pedal
released by the driver, vehicle speed less than or equal to one mile per
hour, engine speed greater than or equal to 50 to 150 rpm below the
normal, warmed-up idle speed (as determined in the drive position for
vehicles equipped with an automatic transmission), and power take-off
not active).

Total run time with power take off active.

For each counter specified in paragraph (k)(6)(i) of this section, the
following numerical value specifications apply:

Each number shall be a four-byte value with a minimum value of zero, a
resolution of one second per bit, and an accuracy of +/- ten seconds per
drive cycle.

Each number shall be reset to zero only when a non-volatile memory reset
occurs (e.g., reprogramming event).  Numbers shall not be reset to zero
under any other circumstances including when a scan tool (generic or
enhanced) command to clear fault codes or reset KAM is received.

To avoid overflow problems, if any of the individual counters reach the
maximum value, all counters shall be divided by two before any are
incremented again.

The counters shall be made available to, at a minimum, a manufacturer
scan tool and may be rescaled when transmitted from a resolution of one
second per bit to no more than three minutes per bit.

(l) Monitoring system demonstration requirements for certification

Monitoring system demonstration requirements for certification.

(l)(1) General

General.

The manufacturer must submit emissions test data from one or more
durability demonstration test engines (test engines).

The Administrator may approve other demonstration protocols if the
manufacturer can provide comparable assurance that the malfunction
criteria are chosen based on meeting the malfunction criteria
requirements and that the timeliness of malfunction detection is within
the constraints of the applicable monitoring requirements.

For flexible fuel engines capable of operating on more than one fuel or
fuel combinations, the manufacturer must submit a plan for providing
emission test data.  The plan must demonstrate that testing will
represent properly the expected in-use fuel or fuel combinations.

(l)(2) Selection of test engines

Selection of test engines.

Prior to submitting any applications for certification for a model year,
the manufacturer must notify the Administrator regarding the planned
engine families and engine ratings within each family for that model
year.  The Administrator will select the engine family(ies) and the
specific engine rating within the engine family(ies) that the
manufacturer shall use as demonstration test engines.  The selection of
test vehicles for production evaluation testing as specified in
paragraph (j)(2) of this section may take place during this selection
process.

The manufacturer must provide emissions test data from the OBD parent
rating as defined in paragraph (o)(1) of this section.

For the test engine, the manufacturer must use an engine aged for a
minimum of 125 hours fitted with exhaust aftertreatment emission
controls aged to be representative of useful life aging.  The
manufacturer is required to submit a description of the accelerated
aging process and/or supporting data.  The process and/or data must
demonstrate assurance that deterioration of the exhaust aftertreatment
emission controls is stabilized sufficiently such that it represents
emission control performance at the end of the useful life.

(l)(3) Required testing

Required testing. Except as otherwise described in this paragraph
(l)(3), the manufacturer must perform single malfunction testing based
on the applicable test with the components/systems set at their
malfunction criteria limits as determined by the manufacturer for
meeting the emissions thresholds required in paragraphs (g), (h), and
(i) of this section.

Required testing for diesel-fueled/compression ignition engines.

Fuel system.  The manufacturer must perform a separate test for each
malfunction limit established by the manufacturer for the fuel system
parameters (e.g., fuel pressure, injection timing) specified in
paragraphs (g)(1)(ii)(A) through (g)(1)(ii)(C) of this section.  When
performing a test for a specific parameter, the fuel system must be
operating at the malfunction criteria limit for the applicable parameter
only.  All other parameters must be operating with normal
characteristics.  In conducting the fuel system demonstration tests, the
manufacturer may use computer modifications to cause the fuel system to
operate at the malfunction limit if the manufacturer can demonstrate
that the computer modifications produce test results equivalent to an
induced hardware malfunction.

[Reserved.]

EGR system.  The manufacturer must perform a separate test for each
malfunction limit established by the manufacturer for the EGR system
parameters (e.g., low flow, high flow, slow response) specified in
paragraphs (g)(3)(ii)(A) through (g)(3)(ii)(C) of this section and in
(g)(3)(ii)(E) of this section.  In conducting the EGR system slow
response demonstration tests, the manufacturer may use computer
modifications to cause the EGR system to operate at the malfunction
limit if the manufacturer can demonstrate that the computer
modifications produce test results equivalent to an induced hardware
malfunction.

Turbo boost control system.  The manufacturer must perform a separate
test for each malfunction limit established by the manufacturer for the
turbo boost control system parameters (e.g., underboost, overboost,
response) specified in paragraphs (g)(4)(ii)(A) through (g)(4)(ii)(C) of
this section and in (g)(4)(ii)(E) of this section.

NMHC catalyst.  The manufacturer must perform a separate test for each
monitored NMHC catalyst(s).  The catalyst(s) being evaluated must be
deteriorated to the applicable malfunction limit established by the
manufacturer for the monitoring required by paragraph (g)(5)(ii)(A) of
this section and using methods established by the manufacturer in
accordance with paragraph (l)(7) of this section.  For each monitored
NMHC catalyst(s), the manufacturer must also demonstrate that the OBD
system will detect a catalyst malfunction with the catalyst at its
maximum level of deterioration (i.e., the substrate(s) completely
removed from the catalyst container or “empty” can).  Emissions data
are not required for the empty can demonstration.

NOx catalyst.  The manufacturer must perform a separate test for each
monitored NOx catalyst(s) (e.g., SCR catalyst).  The catalyst(s) being
evaluated must be deteriorated to the applicable malfunction criteria
established by the manufacturer for the monitoring required by
paragraphs (g)(6)(ii)(A) and (g)(6)(ii)(B) of this section and using
methods established by the manufacturer in accordance with paragraph
(l)(7) of this section.  For each monitored NOx catalyst(s), the
manufacturer must also demonstrate that the OBD system will detect a
catalyst malfunction with the catalyst at its maximum level of
deterioration (i.e., the substrate(s) completely removed from the
catalyst container or “empty” can).  Emissions data are not required
for the empty can demonstration.

NOx adsorber.  The manufacturer must perform a test using a NOx
adsorber(s) deteriorated to the applicable malfunction limit established
by the manufacturer for the monitoring required by paragraph
(g)(7)(ii)(A) of this section. The manufacturer must also demonstrate
that the OBD system will detect a NOx adsorber malfunction with the NOx
adsorber at its maximum level of deterioration (i.e., the substrate(s)
completely removed from the container or “empty” can).  Emissions
data are not required for the empty can demonstration.

Diesel particulate filter.  The manufacturer must perform a separate
test using a DPF deteriorated to the applicable malfunction limits
established by the manufacturer for the monitoring required by
paragraphs (g)(8)(ii)(A), (g)(8)(ii)(B), and (g)(8)(ii)(D) of this
section.  The manufacturer must also demonstrate that the OBD system
will detect a DPF malfunction with the DPF at its maximum level of
deterioration (i.e., the filter(s) completely removed from the filter
container or “empty” can).  Emissions data are not required for the
empty can demonstration.

Exhaust gas sensor.  The manufacturer must perform a separate test for
each malfunction limit established by the manufacturer for the
monitoring required in paragraphs (g)(9)(ii)(A), (g)(9)(iii)(A), and
(g)(9)(iv)(A) of this section.  When performing a test, all exhaust gas
sensors used for the same purpose (e.g., for the same feedback control
loop, for the same control feature on parallel exhaust banks) must be
operating at the malfunction criteria limit for the applicable parameter
only.  All other exhaust gas sensor parameters must be operating with
normal characteristics.

VVT system.  The manufacturer must perform a separate test for each
malfunction limit established by the manufacturer for the monitoring
required in paragraphs (g)(10)(ii)(A) and (g)(10)(ii)(B) of this
section.  In conducting the VVT system demonstration tests, the
manufacturer may use computer modifications to cause the VVT system to
operate at the malfunction limit if the manufacturer can demonstrate
that the computer modifications produce test results equivalent to an
induced hardware malfunction.

For each of the testing requirements of this paragraph (l)(3)(i), if the
manufacturer has established that only a functional check is required
because no failure or deterioration of the specific tested system could
result in an engine’s emissions exceeding the applicable emissions
thresholds, the manufacturer is not required to perform a demonstration
test; however, the manufacturer is required to provide the data and/or
engineering analysis used to determine that only a functional test of
the system(s) is required.

Required testing for gasoline-fueled/spark-ignition engines.

Fuel system. For engines with adaptive feedback based on the primary
fuel control sensor(s), the manufacturer must perform a test with the
adaptive feedback based on the primary fuel control sensor(s) at the
rich limit(s) and a test at the lean limit(s) established by the
manufacturer as required by paragraph (h)(1)(ii)(A) of this section to
detect a malfunction before emissions exceed applicable emissions
thresholds. For engines with feedback based on a secondary fuel control
sensor(s) and subject to the malfunction criteria in paragraph
(h)(1)(ii)(A) of this section, the manufacturer must perform a test with
the feedback based on the secondary fuel control sensor(s) at the rich
limit(s) and a test at the lean limit(s) established by the manufacturer
as required by paragraph (h)(1)(ii)(A) of this section to detect a
malfunction before emissions exceed the applicable emissions thresholds.
For other fuel metering or control systems, the manufacturer must
perform a test at the criteria limit(s). For purposes of fuel system
testing as required by this paragraph (l)(3)(ii)(A), the malfunction(s)
induced may result in a uniform distribution of fuel and air among the
cylinders. Non uniform distribution of fuel and air used to induce a
malfunction shall not cause misfire.  In conducting the fuel system
demonstration tests, the manufacturer may use computer modifications to
cause the fuel system to operate at the malfunction limit. To do so, the
manufacturer must be able to demonstrate that the computer modifications
produce test results equivalent to an induced hardware malfunction.

Misfire. The manufacturer must perform a test at the malfunction
criteria limit specified in paragraph (h)(2)(ii)(B) of this section.

EGR system. The manufacturer must perform a test at each flow limit
calibrated to the malfunction criteria specified in paragraphs
(h)(3)(ii)(A) and (h)(3)(ii)(B) of this section.

Cold start emission reduction strategy. The manufacturer must perform a
test at the malfunction criteria for each component monitored according
to paragraph (h)(4)(ii)(A) of this section.

Secondary air system. The manufacturer must perform a test at each flow
limit calibrated to the malfunction criteria specified in paragraphs
(h)(5)(ii)(A) and (h)(5)(ii)(B) of this section.

Catalyst. The manufacturer must perform a test using a catalyst system
deteriorated to the malfunction criteria specified in paragraph
(h)(6)(ii) of this section using methods established by the manufacturer
in accordance with paragraph (l)(7)(ii) of this section.  The
manufacturer must also demonstrate that the OBD system will detect a
catalyst system malfunction with the catalyst system at its maximum
level of deterioration (i.e., the substrate(s) completely removed from
the catalyst container or “empty” can).  Emission data are not
required for the empty can demonstration.

Exhaust gas sensor. The manufacturer must perform a test with all
primary exhaust gas sensors used for fuel control simultaneously
possessing a response rate deteriorated to the malfunction criteria
limit specified in paragraph (h)(8)(ii)(A) of this section.  The
manufacturer must also perform a test for any other primary or secondary
exhaust gas sensor parameter under parargraphs (h)(8)(ii)(A) and
(h)(8)(iii)(A) of this section that can cause engine emissions to exceed
the applicable emissions thresholds (e.g., shift in air/fuel ratio at
which oxygen sensor switches, decreased amplitude).  When performing
additional test(s), all primary and secondary (if applicable) exhaust
gas sensors used for emission control must be operating at the
malfunction criteria limit for the applicable parameter only.  All other
primary and secondary exhaust gas sensor parameters must be operating
with normal characteristics.

VVT system. The manufacturer must perform a test at each target error
limit and slow response limit calibrated to the malfunction criteria
specified in (h)(9)(ii)(A) and (h)(9)(ii)(B) of this section.  In
conducting the VVT system demonstration tests, the manufacturer may use
computer modifications to cause the VVT system to operate at the
malfunction limit. To do so, the manufacturer must be able to
demonstrate that the computer modifications produce test results
equivalent to an induced hardware malfunction.

For each of the testing requirements of this paragraph (l)(3)(ii), if
the manufacturer has established that only a functional check is
required because no failure or deterioration of the specific tested
system could cause an engine’s emissions to exceed the applicable
emissions thresholds, the manufacturer is not required to perform a
demonstration test; however the manufacturer is required to provide the
data and/or engineering analyses used to determine that only a
functional test of the system(s) is required.

Required testing for all engines.

Other emission control systems.  The manufacturer must conduct
demonstration tests for all other emission control components (e.g.,
hydrocarbon traps, adsorbers) designed and calibrated to a malfunction
limit based on an emissions threshold based on the requirements of
paragraph (i)(4) of this section.

For each of the testing requirements of paragraph (l)(3)(iii)(A) of this
section, if the manufacturer has established that only a functional
check is required because no failure or deterioration of the specific
tested system could result in an engine’s emissions exceeding the
applicable emissions thresholds, the manufacturer is not required to
perform a demonstration test; however, the manufacturer is required to
provide the data and/or engineering analysis used to determine that only
a functional test of the system(s) is required.

The manufacturer may electronically simulate deteriorated components but
shall not make any engine control unit modifications when performing
demonstration tests unless approved by the Administrator.  All equipment
necessary to duplicate the demonstration test must be made available to
the Administrator upon request.

(l)(4) Testing protocol

Testing protocol.

Preconditioning.  The manufacturer must use an applicable cycle for
preconditioning test engines prior to conducting each of the emission
tests required by paragraph (l)(3) of this section.  The manufacturer
may perform a single additional preconditioning cycle, identical to the
initial one, after a 20 minute hot soak but must demonstrate that such
an additional cycle is necessary to stabilize the emissions control
system.  A practice of requiring a cold soak prior to conducting
preconditioning cycles is not permitted.

Test sequence.

The manufacturer must set individually each system or component on the
test engine at the malfunction criteria limit prior to conducting the
applicable preconditioning cycle(s).  If a second preconditioning cycle
is permitted in accordance with paragraph (l)(4)(i) of this section, the
manufacturer may adjust the system or component to be tested before
conducting the second preconditioning cycle.  The manufacturer shall not
replace, modify, or adjust the system or component after the last
preconditioning cycle has been completed.

After preconditioning, the test engine must be operated over the
applicable cycle to allow for the initial detection of the tested system
or component malfunction.  This test cycle may be omitted from the
testing protocol if it is unnecessary.  If required by the monitoring
strategy being tested, a cold soak may be performed prior to conducting
this test cycle.

The test engine must then be operated over the applicable exhaust
emissions test.

[Reserved.]

The manufacturer may request approval to use an alternative testing
protocol for demonstration of MIL activation if the engine dynamometer
emission test cycle does not allow all of a given monitor’s enable
conditions to be satisfied.  The manufacturer may request the use of an
alternative engine dynamometer test cycle or the use of chassis testing
to demonstrate proper MIL activation.  To do so, the manufacturer must
demonstrate the technical necessity for using an alternative test cycle
and the degree to which the alternative test cycle demonstrates that
in-use operation with the malfunctioning component will result in proper
MIL activation.

(l)(5) Evaluation protocol

Evaluation protocol.  Full OBD engine ratings, as defined by paragraph
(o)(1) of this section, shall be evaluated according to the following
protocol:

For all tests conducted as required by paragraph (l) of this section,
the MIL must activate before the end of the first engine start portion
of the applicable test.

If the MIL activates prior to emissions exceeding the applicable
malfunction criteria limits specified in paragraphs (g) through (i) of
this section, no further demonstration is required.  With respect to the
misfire monitor demonstration test, if the manufacturer has elected to
use the minimum misfire malfunction criteria of one percent as allowed
in paragraph (h)(2)(ii)(B) of this section, no further demonstration is
required provided the MIL activates with engine misfire occurring at the
malfunction criteria limit.

If the MIL does not activate when the system or component is set at its
malfunction criteria limit(s), the criteria limit(s) or the OBD system
is not acceptable.

Except for testing of the catalyst or DPF system, if the MIL first
activates after emissions exceed the applicable malfunction criteria
specified in paragraphs (g) through (i) of this section, the test engine
shall be retested with the tested system or component adjusted so that
the MIL will activate before emissions exceed the applicable malfunction
criteria specified in paragraphs (g) through (i) of this section.  If
the component cannot be so adjusted because an alternative fuel or
emission control strategy is used when a malfunction is detected (e.g.,
open loop fuel control used after an oxygen sensor malfunction is
detected), the test engine shall be retested with the component adjusted
to the worst acceptable limit (i.e., the applicable OBD monitor
indicates that the component is performing at or slightly better than
the malfunction criteria limit).  When tested with the component so
adjusted, the MIL must not activate during the test and the engine
emissions must be below the applicable malfunction criteria specified in
paragraphs (g) through (i) of this section.

In testing the catalyst or DPF system, if the MIL first activates after
emissions exceed the applicable emissions threshold(s) specified in
paragraphs (g) and (h) of this section, the tested engine shall be
retested with a less deteriorated catalyst or DPF system (i.e., more of
the applicable engine out pollutants are converted or trapped).  For the
OBD system to be approved, testing shall be continued until the MIL
activates with emissions below the applicable thresholds of paragraphs
(g) and (h) of this section, or the MIL activates with emissions within
a range no more than 20 percent below the applicable emissions
thresholds and 10 percent or less above those emissions thresholds.

If an OBD system is determined to be unacceptable by the criteria of
this paragraph (l)(5) of this section, the manufacturer may recalibrate
and retest the system on the same test engine.  In such a case, the
manufacturer must confirm, by retesting, that all systems and components
that were tested prior to the recalibration and are affected by it still
function properly with the recalibrated OBD system.

(l)(6) Confirmatory testing

Confirmatory testing.

The Administrator may perform confirmatory testing to verify the
emission test data submitted by the manufacturer as required by this
paragraph (l) of this section comply with its requirements and the
malfunction criteria set forth in paragraphs (g) through (i) of this
section.  Such confirmatory testing is limited to the test engine
required by paragraph (l)(2) of this section.

To conduct this confirmatory testing, the Administrator may install
appropriately deteriorated or malfunctioning components (or simulate
them) in an otherwise properly functioning test engine of an engine
rating represented by the demonstration test engine in order to test any
of the components or systems required to be tested by paragraph (l) of
this section.  The manufacturer shall make available, if requested, an
engine and all test equipment (e.g., malfunction simulators,
deteriorated components) necessary to duplicate the manufacturer’s
testing.  Such a request from the Administrator shall occur within six
months of reviewing and approving the demonstration test engine data
submitted by the manufacturer for the specific engine rating.

(l)(7) Catalyst aging

Catalyst aging.

Diesel catalysts. For purposes of determining the catalyst malfunction
limits for the monitoring required by paragraphs (g)(5)(ii)(A),
(g)(5)(ii)(B), and (g)(6)(ii)(A) of this section, where those catalysts
are monitored individually, the manufacturer must use a catalyst
deteriorated to the malfunction criteria using methods established by
the manufacturer to represent real world catalyst deterioration under
normal and malfunctioning engine operating conditions.  For purposes of
determining the catalyst malfunction limits for the monitoring required
by paragraphs (g)(5)(ii)(A), (g)(5)(ii)(B), and (g)(6)(ii)(A) of this
section, where those catalysts are monitored in combination with other
catalysts, the manufacturer must submit their catalyst system aging and
monitoring plan to the Administrator as part of their certification
documentation package.  The plan must include the description, emission
control purpose, and location of each component, the monitoring strategy
for each component and/or combination of components, and the method for
determining the applicable malfunction criteria including the
deterioration/aging process.

Gasoline catalysts. For the purposes of determining the catalyst system
malfunction criteria in paragraph (h)(6)(ii) of this section, the
manufacturer must use a catalyst system deteriorated to the malfunction
criteria using methods established by the manufacturer to represent real
world catalyst deterioration under normal and malfunctioning operating
conditions. The malfunction criteria must be established by using a
catalyst system with all monitored and unmonitored (downstream of the
sensor utilized for catalyst monitoring) catalysts simultaneously
deteriorated to the malfunction criteria except for those engines that
use fuel shutoff to prevent over-fueling during engine misfire
conditions. For such engines, the malfunction criteria must be
established by using a catalyst system with all monitored catalysts
simultaneously deteriorated to the malfunction criteria while
unmonitored catalysts shall be deteriorated to the end of the engine’s
useful life.

(m) Certification documentation

Certification documentation requirements.

When submitting an application for certification of an engine, the
manufacturer must submit the following documentation. If any of the
items listed here are standardized for all of the manufacturer’s
engines, the manufacturer may, for each model year, submit one set of
documents covering the standardized items for all of its engines.

For the required documentation that is not standardized across all
engines, the manufacturer may be allowed to submit documentation for
certification from one engine that is representative of other engines.
All such engines shall be considered to be part of an OBD certification
documentation group.  To represent the OBD group, the chosen engine must
be certified to the most stringent emissions standards and OBD
monitoring requirements and cover all of the emissions control devices
for the engines in the group and covered by the submitted documentation.
 Such OBD groups must be approved in advance of certification.

Upon approval, one or more of the documentation requirements of this
paragraph (m) of this section may be waived or modified if the
information required is redundant or unnecessarily burdensome to
generate.

To the extent possible, the certification documentation must use SAE
J1930 or J2403 terms, abbreviations, and acronyms.

Unless otherwise specified, the following information must be submitted
as part of the certification application and prior to receiving a
certificate.

A description of the functional operation of the OBD system including a
complete written description for each monitoring strategy that outlines
every step in the decision-making process of the monitor.  Algorithms,
diagrams, samples of data, and/or other graphical representations of the
monitoring strategy shall be included where necessary to adequately
describe the information.

A table including the following information for each monitored component
or system (either computer-sensed or computer-controlled) of the
emissions control system:

Corresponding diagnostic trouble code.

Monitoring method or procedure for malfunction detection.

Primary malfunction detection parameter and its type of output signal.

Malfunction criteria limits used to evaluate output signal of primary
parameter.

Other monitored secondary parameters and conditions (in engineering
units) necessary for malfunction detection.

Monitoring time length and frequency of monitoring events.

Criteria for storing a diagnostic trouble code.

Criteria for activating a malfunction indicator light.

Criteria used for determining out-of-range values and input component
rationality checks.

Whenever possible, the table required by paragraph (m)(2)(ii) of this
section shall use the following engineering units:

Degrees Celsius for all temperature criteria.

KiloPascals (KPa) for all pressure criteria related to manifold or
atmospheric pressure.

Grams (g) for all intake air mass criteria.

Pascals (Pa) for all pressure criteria related to evaporative system
vapor pressure.

Miles per hour (mph) for all vehicle speed criteria.

Relative percent (%) for all relative throttle position criteria (as
defined in SAE J1979/J1939).

Voltage (V) for all absolute throttle position criteria (as defined in
SAE J1979/J1939).

Per crankshaft revolution (/rev) for all changes per ignition event
based criteria (e.g., g/rev instead of g/stroke or g/firing).

Per second (/sec) for all changes per time based criteria (e.g., g/sec).

Percent of nominal tank volume (%) for all fuel tank level criteria.

A logic flowchart describing the step-by-step evaluation of the enable
criteria and malfunction criteria for each monitored emission related
component or system.

Emissions test data, a description of the testing sequence (e.g., the
number and types of preconditioning cycles), approximate time (in
seconds) of MIL activation during the test, diagnostic trouble code(s)
and freeze frame information stored at the time of detection,
corresponding test results (e.g. SAE J1979 Mode/Service $06, SAE J1939
Diagnostic Message 8 (DM8)) stored during the test, and a description of
the modified or deteriorated components used for malfunction simulation
with respect to the demonstration tests specified in paragraph (l) of
this section.  The freeze frame data are not required for engines
subject to paragraph (o)(2) of this section.

For gasoline engines, data supporting the misfire monitor, including:

The established percentage of misfire that can be tolerated without
damaging the catalyst over the full range of engine speed and load
conditions.

Data demonstrating the probability of detection of misfire events by the
misfire monitoring system over the full engine speed and load operating
range for the following misfire patterns: random cylinders misfiring at
the malfunction criteria established in paragraph (h)(2)(ii)(B) of this
section, one cylinder continuously misfiring, and paired cylinders
continuously misfiring.

Data identifying all disablement of misfire monitoring that occurs
during the FTP.  For every disablement that occurs during the cycles,
the data shall identify: when the disablement occurred relative to the
driver’s trace, the number of engine revolutions during which each
disablement was present, and which disable condition documented in the
certification application caused the disablement.

Manufacturers are not required to use the durability demonstration
engine to collect the misfire data required by paragraph (m)(2)(vi) of
this section.

Data supporting the limit for the time between engine starting and
attaining the designated heating temperature for after-start heated
catalyst systems.

Data supporting the criteria used to detect a malfunction of the fuel
system, EGR system, boost pressure control system, catalyst, NOx
adsorber, DPF, cold start emission reduction strategy, secondary air,
evaporative system, VVT system, exhaust gas sensors, and other emission
controls that causes emissions to exceed the applicable malfunction
criteria specified in paragraphs (g) through (i) of this section.  For
diesel engine monitors required by paragraphs (g) and (i) of this
section that are required to indicate a malfunction before emissions
exceed an emission threshold based on any applicable standard (e.g., 2.5
times any of the applicable standards), the test cycle and standard
determined by the manufacturer to be the most stringent for each
applicable monitor in accordance with paragraph (f)(1) of this section.

A list of all electronic powertrain input and output signals (including
those not monitored by the OBD system) that identifies which signals are
monitored by the OBD system.  For input and output signals that are
monitored as comprehensive components, the listing shall also identify
the specific diagnostic trouble code for each malfunction criteria
(e.g., out-of-range low, out-of-range high, open circuit, rationality
low, rationality high).

A written description of all parameters and conditions necessary to
begin closed-loop/feedback control of emission control systems (e.g.,
fuel system, boost pressure, EGR flow, SCR reductant delivery, DPF
regeneration, fuel system pressure).

A written identification of the communication protocol utilized by each
engine for communication with a scan tool.

[Reserved.]

A written description of the method used by the manufacturer to meet the
requirements of paragraph (i)(2) of this section (crankcase ventilation
system monitoring) including diagrams or pictures of valve and/or hose
connections.

Build specifications provided to engine purchasers or chassis
manufacturers detailing all specifications or limitations imposed on the
engine purchaser relevant to OBD requirements or emissions compliance
(e.g., cooling system heat rejection rates).  A description of the
method or copies of agreements used to ensure engine purchasers or
chassis manufacturers will comply with the OBD and emissions relevant
build specifications (e.g., signed agreements, required audit/evaluation
procedures).

Any other information determined by the Administrator to be necessary to
demonstrate compliance with the requirements of this section.

(n) Deficiencies

Deficiencies.

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 is 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 shall not be
carried over from the previous model year except where unreasonable
hardware or software modifications are 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,
air-fuel ratio sensor, NOx sensor, engine misfire, evaporative leaks,
and diesel EGR, if equipped), with the possible exception of the special
provisions for alternative fueled engines. For alternative fueled
heavy-duty engines (e.g. natural gas, liquefied petroleum gas, methanol,
ethanol), 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 alternative fuel. At a minimum,
alternative fuel engines must be equipped with an OBD system meeting OBD
requirements to the extent feasible as approved by the Administrator.

In the event the manufacturer seeks to carry-over a deficiency from a
past model year to the current model year, the manufacturer must
re-apply for approval to do so. In considering the request to carry-over
a deficiency, the Administrator shall consider the manufacturer’s
progress towards correcting the deficiency.  The Administrator may not
allow manufacturers to carry over monitoring system deficiencies for
more than two model years unless it can be demonstrated that substantial
engine hardware modifications and additional lead time beyond two years
are necessary to correct the deficiency.

A deficiency shall not be granted retroactively (i.e., after the engine
has been certified).

(o) Implementation schedule

Implementation schedule. Except as provided for in paragraphs (o)(4) and
(o)(5) of this section, the requirements of this section must be met
according to the following provisions:

Full OBD. The manufacturer must implement an OBD system meeting the
requirements of this section on one engine rating within one engine
family of the manufacturer’s product line. This “full OBD” rating
will be known as the “OBD parent” rating.  The OBD parent rating
must be chosen as the rating having the highest weighted projected US
sales within the engine family having the highest weighted projected US
sales, with US sales being weighted by the useful life of the engine
rating.

Extrapolated OBD. For all other engine ratings within the engine family
from which the OBD parent rating has been selected, the manufacturer
must implement an OBD system meeting the requirements of this section
except that the OBD system is not required to detect a malfunction prior
to exceeding the emission thresholds shown in Table 1 of paragraph (g)
of this section and Table 2 of paragraph (h) of this section. These
extrapolated OBD engines will be know as the “OBD child” ratings. On
these OBD child ratings, rather than detecting a malfunction prior to
exceeding the emission thresholds, the manufacturer must submit a plan
for Administrator review and approval that details the engineering
evaluation the manufacturer will use to establish the malfunction
criteria for the OBD child ratings.  The plan must demonstrate both the
use of good engineering judgment in establishing the malfunction
criteria, and robust detection of malfunctions, including consideration
of differences of base engine, calibration, emission control components,
and emission control strategies.

Engine families other than those from which the parent and child ratings
have been selected, are not subject to the requirements of this section.

Small volume manufacturers, as defined in §86.094-14(b)(1) and (2), are
exempt from the requirements of §86.010-18.

Engines certified as alternative fueled engines are exempt from the
requirements of §86.010-18.