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ECE/TRANS/180/Add.18/Amend.1
January 18, 2021
GLOBAL REGISTRY
Created on November 18, 2004, Pursuant to Article 6 of the
AGREEMENT CONCERNING THE ESTABLISHING OF GLOBAL TECHNICAL
REGULATIONS FOR WHEELED VEHICLES, EQUIPMENT AND PARTS WHICH
CAN BE FITTED AND/OR BE USED ON WHEELED VEHICLES
(ECE/TRANS/132 and Corr.1)
DONE AT GENEVA ON JUNE 25, 1998
Addendum 18:
UN GLOBAL TECHNICAL REGULATION NO. 18
UN GLOBAL TECHNICAL REGULATION ON THE MEASUREMENT PROCEDURE
FOR TWO- OR THREE-WHEELED MOTOR VEHICLES WITH REGARD TO
ON-BOARD DIAGNOSTICS
(ESTABLISHED IN THE GLOBAL REGISTRY ON NOVEMBER 17, 2016)
Incorporating:
Amendment 1 dated January 18, 2021

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UN GLOBAL TECHNICAL REGULATION NO. 18
I. STATEMENT OF TECHNICAL RATIONALE AND JUSTIFICATION
A. INTRODUCTION
1. The industry producing two- and three-wheeled vehicles in the scope of this United Nations
Global Technical Regulation (UN GTR) is a global one, with companies selling their
products in many different countries. The Contracting Parties to the 1998 Agreement have
determined that work should be undertaken to address the environmental and propulsion
unit performance requirements of two- and three-wheeled light motor vehicles, among
others as a way to help improve air quality internationally. Currently, the UN GTR is directed
at harmonizing On-Board Diagnostic requirements (OBD) for two- and three-wheeled
vehicles, similar as targeted with UN GTR No. 5 for heavy duty vehicles. This common set
of agreed rules in the area of OBD allows the Contracting Parties to realize their own
domestic objectives and to pursue their own levels of priorities. Nonetheless, as discussed
in more detail below, the UN GTR has been structured in a manner that facilitates a wider
application of OBD to other vehicle systems and objectives in the future.
2. This UN GTR establishes harmonized functional requirements for OBD and a procedure to
test and verify the environmental OBD functions (Test Type VIII). The functional
requirements and test procedures were developed so that they would be able to provide an
internationally harmonized set of functional OBD requirements with respect to the
"infra-structure" on-board of a vehicle in the scope of this UN GTR, which determines
hardware and software design in a technology neutral way and that considers technical
feasibility and cost-effectiveness.
3. The UN GTR also covers harmonized requirements to conduct the environmental
verification test procedure (Test Type VIII) relating to OBD, which is a test procedure by
simulating a failure of an emission relevant component in the powertrain management
system and its emission control system. Subsequently the OBD system reaction and
containment of the failure is monitored and reported during Type I test tailpipe emission
verification tests.
4. OBD should not oblige manufacturers to change or add fuelling or ignition hardware and
should not impose fitting of an electronic carburettor, electronic fuel injection or
electronically controlled ignition coils, providing the vehicle complies with the applicable
environmental performance requirements. Compliance with the OBD requirements implies
that if fuel delivery, spark delivery or intake air hardware is electronically controlled, the
applicable input or output circuits need to be monitored, limited to the items and failure
modes listed in Table A2/1 of Annex 2.
5. This UN GTR is based on the work of the Informal Working Group (IWG) on Environmental
and Propulsion unit Performance Requirements (EPPR) of vehicles, from now on referred to
as EPPR IWG, which held its first meeting during the sixty-fifth GRPE in January 2013 and
on the initial proposal by the European Union (EU, represented by the European
Commission (EC)).

---

2. Methodology for Deriving Harmonized Test Procedures for the UN GTR
11. The European Commission launched an EPPR study for L-Category vehicles in
January 2012 with the objective to develop proposals to update UN GTR No. 2 for technical
progress and to develop proposals for UN GTRs and Regulations with respect to
harmonized EPPR legislation not yet covered at the international level for two- and
three-wheeled vehicles, e.g. crankcase and evaporative emission test requirements,
on-board diagnostic requirements, propulsion unit performance requirements, etc. The
output of this comprehensive study was submitted for the review and comments of the
EPPR IWG with the objective to identify concerns and to provide base proposals ready for
further enhancements by the EPPR IWG in order to accommodate the needs at the
international level to assess a vehicle with respect to on-board diagnostics in a scientifically
based, objective and globally accepted way.
12. The outcome of this work was among others the development of the UN GTR 18 on OBD
based on the EC regulation. Based on the same EC regulation the first draft of the
amendment to UN GTR 18 to include OBD II was drawn. This text then further evolved in
many different revisions and was modified in iterative steps to reflect the discussions and
decisions by the Group over the period 2018 - 2020.
13. Because the need of one of the Contracting Parties, the work was divided into two phases in
order to provide the basis of the national regulation on areas of urgency, leaving for the
second phase the rest of the areas to be addressed in the amendment. The work of phase
one was concluded in March 2019 (GRPE-79-23).
D. DISCUSSION OF THE ISSUES ADDRESSED BY THE UN GTR
1. List of Issues
14. This UN GTR brings together the harmonized test procedures with regard to on-board
diagnostic requirements for the certification of vehicles in the scope of this UN GTR. The
process to develop this UN GTR followed the methodology discussed in Chapter C.2, where
important issues discussed and addressed during the development were, among others:
(a)
(b)
(c)
Access to OBD; in particular access to vehicle security features
Catalytic converter monitoring
Environmental performance related functions and functional safety ('limp-home'
operating mode which significantly reduces engine torque).
(d) Introduction by the Contracting Parties of OTL 2 and OTL 1.

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3. Scope
17. The EPPR IWG has discussed at length which vehicle types should be in the scope of the
UN GTR. One of the objectives of the Group was to discuss the substantive requirements of
two-wheeled vehicles first followed by a discussion if these requirements should as well be
applied to three-wheeled vehicles. In particular it was debated whether or not the
classification criteria laid down in Paragraph 2. of Special Resolution No. 1 (S.R.1) on
Category 3 vehicles should be referenced in detail or using a more generic wording,
e.g. two- and three-wheeled vehicles or motorcycles allowing for more flexibility to allow
alignment with domestic classification of three-wheeled vehicles.
18. The EPPR IWG discussed possible solutions how three-wheeled vehicles could be included
in the scope of the UN GTR given the fact that S.R.1 contains recommended classification
criteria for Category 3 vehicles that might require an update for technical progress. Finally, it
was agreed to put "Category 3" vehicls in Paragraph 2. of the UN GTR and to reference
S.R.1 in a footnote.
19. Contracting Parties may expand the scope to other types of three-wheeled vehicles in order
to align with their domestic classifications of three-wheeled vehicles as deemed appropriate.
4. Definitions
20. The definitions used in the UN GTR are aligned as much as possible with definitions in
international legislation and from the work of the Vehicle Propulsion System Definitions
(VPSD) Group operating under GRPE with the goal to harmonize high level powertrain
definitions as well as from other regional legislation as listed in Chapter C.1. The definitions
set out in Mutual Resolution No. 2 were re-used where possible in this UN GTR.
21. In the definition of "useful life" a reference to a period of time has been included, because of
the following reasons:
(a)
(b)
Firstly, the general life cycle for industrial products is prescribed by its life period, so
the time is the necessary parameter to define the life cycle. For instance, if a vehicle
with the product warranty for "ten years and total mileage of one-hundred-thousand
kilometres" has only one kilometre as total mileage but is 20-years old, the vehicle
should not be regarded as in-warranty.
Secondly, the definition in the UN GTR on crankcase and evaporative emissions is
also referring to the period of distance and time.
5. Requirements
22. Regarding functional requirements for OBD, the UN GTR contains the following main items:
(a) Minimum monitoring requirements for OBD Stage I;
(b)
(c)
(d)
Provisions regarding design of the Malfunction Indicator (MI), diagnostic trouble
codes, diagnostic signals and connection interfaces;
Provisions regarding access to OBD information;
Definition of propulsion unit families with regard to OBD.

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II.
TEXT OF THE UN GLOBAL TECHNICAL REGULATION
1. PURPOSE
1.1. This UN GTR prescribes the requirements for On-Board Diagnostic (OBD) systems
to detect, record and/or communicate failures of specific vehicle and engine
systems that affect the environmental performance of these systems, as described
in the specific Annexes to this UN GTR.
1.2. In addition, this UN GTR specifies the elements concerning the OBD system to
facilitate the diagnosis, efficient and effective repair and maintenance of specific
vehicle and engine systems without containing mandatory prescriptions for this
purpose.
1.3. OBD should not oblige manufacturers to change or add fuelling or ignition hardware
and should not impose fitting of an electronic carburettor, electronic fuel injection or
electronically controlled ignition coils, providing the vehicle complies with the
applicable environmental performance requirements. Compliance with the OBD
requirements implies that if fuel delivery, spark delivery or intake air hardware is
electronically controlled, the applicable input or output circuits need to be monitored,
limited to the items and failure modes listed in Table A2/1 of Annex 2.
2. SCOPE AND APPLICATION
Vehicle with
PI engine
Vehicle with
CI engine
Two- and three-wheeled vehicles of Category 3 equipped with a propulsion unit in
accordance with Table 1.
Table 1
Scope with Regard to the Propulsion Unit and Fuel Type
Propulsion unit and fuel type
Functional
OBD
Test Type VIII
Mono-fuel Petrol Yes Yes
Mono-fuel Diesel Yes Yes

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3.13. A "key cycle" consists of engine key-on, engine cranking and idling where a
malfunction would be detected if present, followed by engine key-off.
3.14. "Limp-home" means an operation mode triggered by the control system that
restricts fuel quantity, intake air quantity, spark delivery or other powertrain control
variables resulting in significant reduction of output torque under default mode;
3.15. "Malfunction Indicator (MI)" for Category 3 vehicle* means a visible indicator that
clearly informs the driver of the vehicle in the event of malfunction(s);
3.16. "Malfunction" for Category 3 vehicle* means the failure of a component or system
that would result in emissions exceeding the OBD threshold limits (OTL) set out in
Paragraph 5.5.1. of general requirements, the circuit failure or the OBD system
being unable to fulfil the basic monitoring requirements;
A Contracting Party may require triggering of Limp-home as the definition of
"malfunction for Category 3 vehicle*".
3.17. "On-Board Diagnostic(OBD) system" for category 3 vehicle* means an electronic
system fitted on-board of a vehicle that has the capability of identifying the likely
area of malfunction by means of fault codes stored in a computer memory which
can be accessed by means of a generic scan tool;
3.18. "Pending fault code" is a diagnostic trouble code stored upon the initial detection
of a malfunction prior to illumination of the malfunction indicator.
3.19. "Permanent emission default mode" refers to a case where the engine
management controller permanently switches to a setting that does not require an
input from a failed component or system where such a failed component or system
would result in increasing emissions from the vehicle exceeding the OBD threshold
limits set out in this UN GTR;
3.20. "Power take-off unit" means an engine-driven output provision for the purposes of
powering ancillary, vehicle‐mounted equipment;
3.21. "Repair information" means all information required for diagnosis, servicing,
inspection, periodic monitoring or repair of the vehicle and which the manufacturers
provide for their authorized dealers/repair shops or for manufacturers of
replacement or retrofit components which are compatible with the vehicle OBD
system. Where necessary, such information shall include service handbooks,
technical manuals, diagnosis information (e.g. minimum and maximum theoretical
values for measurements), wiring diagrams, the software calibration identification
number applicable to a vehicle type, instructions for individual and special cases,
information provided concerning tools and equipment, data record information and
bi-directional monitoring and test data as specified in Paragraph 3.8. of Annex 1.
The manufacturer shall also make accessible, where appropriate on payment, the
technical information required for the repair or maintenance of motor vehicles unless
that information is covered by an intellectual property right or constitutes essential,
secret know-how which is identified in an appropriate form; in such case, the
necessary technical information shall not be withheld improperly;

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4. List of Acronyms and Symbols
Item
Unit
Term
APS
–
accelerator (pedal/handle) position sensor
CAN
–
controller area network
CARB
–
California air resources board
CI
–
compression ignition engine
CO
mg/km
carbon monoxide
CO
mg/km
carbon dioxide
CVN
calibration verification number
deNO
nitric oxide reduction system
DF
deterioration factors
DTC
diagnostic trouble code
ECU
–
engine control unit
EGR
exhaust gas recirculation system
EPA
–
United States Environmental Protection Agency
ETC
–
electronic throttle control
HC
mg/km
hydrocarbons
ID
–
identifier
ISO
–
international standardisation organisation
IUPR
in-use performance ratio
IUPR
in-use performance ratio of a specific monitor
KAM
keep alive memory
MI
–
malfunction indicator
NMHC
mg/km
non-methane hydrocarbon
NO
mg/km
nitrogen oxides
OBD
on-board diagnosis
ODX
–
open diagnostic data exchange
OTL
OBD threshold limits
PCU
–
powertrain control unit
PI
–
positive ignition engine
PID
–
parameter identifier

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5.3.2.1. Access to the OBD system required for the inspection, diagnosis, servicing or repair
of the vehicle shall be unrestricted and standardised. All OBD relevant diagnostic
trouble codes shall be consistent with Paragraph 3.11. of Annex 1.
5.3.2.2. At the manufacturer's discretion, to aid technicians in the efficient repair of vehicles,
the OBD system may be extended to monitor and report on any other on-board
system. Extended diagnostic systems shall not be considered as falling under the
scope of certification requirements.
5.3.3. Monitoring Requirements of Electric Circuit and Electronics Failure
For the purposes of Paragraph 5.3.1., 5.3.7. and 5.3.8, the electric circuit and
electronic failure diagnostics with regard to OBD shall at a minimum contain the
sensor and actuator diagnostics as well as the internal diagnostics of the electronic
control units required in Table A2/1 of Annex 2.
5.3.4. Monitoring Requirements for Vehicles Equipped with Positive-ignition Engines
The OBD system shall indicate the failure of an emission-related component or
system when that failure results in emissions exceeding the OBD threshold limits
referred to in Paragraph 5.5.1. In satisfying the requirements of Paragraph 5.3.1.,
the OBD system shall, at a minimum, monitor for:
5.3.4.1. Catalytic Converter Deterioration and Performance
The reduction in the efficiency of the catalytic converter with respect to emissions of
hydrocarbons and nitrogen oxides shall be monitored. Manufacturers may monitor
the front catalyst alone or in combination with the next catalyst(s) downstream. Each
monitored catalyst or catalyst combination shall be considered to be malfunctioning
if the emissions exceed the NMHC or NO thresholds identified in Paragraph 5.5.1.
5.3.4.2. Notwithstanding Paragraph 5.3.4.1., a Contracting Party may choose not to require
the monitoring of the catalytic converter.
(a)
(b)
A Contracting Party not requiring the monitoring of the catalytic converter may
prescribe other conditions that the exhaust system needs to satisfy.
A Contracting Party may apply Paragraph 5.3.4.2. to limited vehicle class(es).
5.3.4.3. Engine Misfire
The presence of engine misfire in the engine operating region bounded by the
following lines:
(a)
(b)
Low speed limit: A minimum speed of 2,500min or normal idle speed
+1,000min , whichever is the lower
High speed limit: A maximum speed of 8,000min or 1,000min greater than
the highest speed occurring during a Type I test cycle or maximum design
engine speed minus 500min , whichever is lower

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5.3.4.6. For direct injection positive ignition engines, any malfunction that could lead to
emissions exceeding the particulate mass (PM) OBD threshold limits provided in
Paragraph 5.5.1. shall be monitored in accordance with the requirements of this
section for compression ignition engines.
5.3.5. Monitoring Requirements for Vehicles Equipped with Compression Ignition Engines
The OBD system shall indicate the failure of an emission-related component or
system when that failure results in emissions exceeding the OBD threshold limits
referred to in Paragraph 5.5.1.
In satisfying the requirements of Paragraph 5.3.1., the OBD system shall, at a
minimum, monitor for:
5.3.5.1. Catalytic Converter Deterioration and Performance.
Reduction in the efficiency of the catalytic converter, where fitted;
5.3.5.2. Notwithstanding Paragraph 5.3.5.1., a Contracting Party may choose not to require
the monitoring of the catalytic converter.
5.3.5.3. The functionality and integrity of the particulate trap, where fitted.
5.3.5.4. The fuel-injection system electronic fuel quantity and timing actuator(s) is/are
monitored for circuit continuity and total functional failure.
5.3.5.5. Malfunctions and the reduction in efficiency of the EGR system, shall be monitored.
5.3.5.6. Malfunctions and the reduction in efficiency of a NO after-treatment system using a
reagent and the reagent dosing subsystem shall be monitored.
5.3.5.7. Malfunctions and the reduction in efficiency of NO after-treatment not using a
reagent shall be monitored.
5.3.6. If active, the emission control system components or systems, or emission-related
powertrain components or systems, which are connected to a computer shall be
monitored, the failure of which may result in tailpipe emissions exceeding the OBD
threshold limits given in Paragraph 5.5.1.
5.3.7.
(a)
Unless otherwise monitored, any other electronic powertrain component
connected to a computer relevant for environmental performance, including
any relevant sensors to enable monitoring functions to be carried out, shall be
monitored for electric/electronic circuit failures. In particular these electronic
components shall be continuously monitored for any electric circuit continuity
failure, shorted electric circuits, electric range/performance and stuck signal
of the emissions control system.
(b)
A Contracting Party may require in addition that any other electronic
powertrain component connected to a computer relevant for functional safety,
including any relevant sensors to enable monitoring functions to be carried
out, shall be monitored for electric/electronic circuit failures.

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5.3.11.2. Engine Misfire in Vehicles Equipped with Positive-ignition Engines.
5.3.11.2.1. Manufacturers may adopt higher misfire percentage malfunction criteria than those
declared to the authority, under specific engine speed and load conditions where it
can be demonstrated to the authority that the detection of lower levels of misfire
would be unreliable. In terms of OBD monitoring, it is that percentage of misfires out
of a total number of firing events (as declared by the manufacturer) that would result
in emissions exceeding the OBD threshold limits set out in Paragraph 5.5.1., or that
percentage that could lead to an exhaust catalyst(s) overheating, causing
irreversible damage.
5.3.11.2.2. When a manufacturer can demonstrate to the authority that the detection of higher
levels of misfire percentages is still not feasible, or that misfire cannot be
distinguished from other effects (e.g. rough roads, transmission shifts, after engine
starting, etc.), the misfire monitoring system may be disabled when such conditions
exist.
5.3.11.3. Identification of deterioration or malfunctions may also be done outside a driving
cycle (e.g. after engine shutdown).
5.3.12. Activation of the Malfunction Indicator (MI)
5.3.12.1. The OBD system shall incorporate a malfunction indicator readily perceivable to the
vehicle operator. The MI shall not be used for any purposes other than to indicate
emergency start-up or limp-home routines to the driver. The MI shall be visible in all
reasonable lighting conditions. When activated, it shall display a symbol in
conformity with ISO 2575:2010, Symbol F.01. A vehicle shall not be equipped with
more than one general purpose MI for emission-related problems or powertrain
faults leading to significantly reduced torque. Separate specific purpose tell-tales
(e.g. brake system, fasten seat belt, oil pressure, etc.) are permitted. The use of red
colour for an MI is prohibited.
5.3.12.2. For strategies requiring more than two preconditioning cycles for MI activation, the
manufacturer shall provide data and/or an engineering evaluation which adequately
demonstrate that the monitoring system is equally effective and timely in detecting
component deterioration. Strategies requiring on average more than ten driving
cycles for MI activation are not accepted.
(a)
(b)
The MI shall also activate whenever the powertrain control enters a
permanent emission default mode of operation if the OBD threshold limits in
Paragraph 5.5.1. are exceeded or if the OBD system is unable to fulfil the
basic monitoring requirements laid down in Paragraph 5.3.4 or 5.3.5.
A Contracting Party may require in addition that the MI shall activate
whenever the powertrain control enters a limp home mode.
5.3.12.3. The MI shall operate in a distinct warning mode, e.g. a flashing light, during any
period in which engine misfire occurs at a level likely to cause catalyst damage, as
specified by the manufacturer.

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5.3.13.3. The MI may be activated at levels of emissions below the OBD threshold limits set
out in Paragraph 5.5.1.
5.3.13.4. The MI may be activated if a default mode is active without significant reduction of
propulsion torque.
5.3.14. Extinguishing the MI
5.3.14.1. If misfire at levels likely to cause catalyst damage (as specified by the manufacturer)
is no longer taking place, or if the engine is operated after changes to speed and
load conditions where the level of misfire will not cause catalyst damage, the MI
may be switched back to the previous state of activation during the first driving cycle
on which the misfire level was detected and to the normal activated mode on
subsequent driving cycles. If the MI is switched back to the previous state of
activation, the corresponding fault codes and stored freeze-frame conditions may be
erased.
5.3.14.2. For all other malfunctions, the MI may be deactivated after three subsequent
sequential driving cycles during which the monitoring system responsible for
activating the MI ceases to detect the malfunction and if no other malfunction has
been identified that would independently activate the MI.
5.3.15. Erasing a Diagnostic Trouble Code
5.3.15.1. The OBD system may erase a diagnostic trouble code and the distance travelled
and freeze-frame information if the same fault is not re-registered in at least
40 engine warm-up cycles.
5.3.15.2. Stored faults shall not be erased by disconnection of the on-board computer from
the vehicle power supply or by disconnection or failure of the vehicle battery or
batteries.
5.3.16. Additional Provisions for Vehicles Employing Engine Shut-off Strategies
5.3.16.1. Driving Cycle
5.3.16.1.1. Autonomous engine restarts commanded by the engine control system following an
engine stall may be considered a new driving cycle or a continuation of the existing
driving cycle.
5.4. Requirements Relating to the Certification of On-board Diagnostic Systems
5.4.1. A manufacturer may ask the responsible authority to accept an OBD system for
certification even if the system contains one or more deficiencies so that the specific
requirements of this UN GTR are not fully met.

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5.5.1.
Pollutant (mg/km)
CO HC NMHC NO PM
OTL 1
Principal
OTL 2
Enhanced
PI Class 1/2
2170
1400
–
350
–
PI Class 3
2170
630
–
450
–
CI
2170
630
–
900
–
PI
1900
–
250
300
50
CI
1900
–
320
540
50
5.5.2. Contracting Parties may either introduce OTL 2 directly or after the introduction of
OTL 1.
5.6. Propulsion Family Definition with Regard to OBD and in Particular to Test
Type VIII
5.6.1. A representative parent vehicle shall be selected to test and demonstrate to the
responsible authority the functional on-board diagnostic requirements set out in
Annex 1 and to verify the Test Type VIII requirements laid down in Annex 6 based
on the propulsion family definition laid down in Table A7/1 of Annex 7 or vehicle
parameters referred to Annex 5. All members of the family shall comply with the
applicable requirements and OBD threshold limits set out in this UN GTR.
5.7. Documentation
The vehicle manufacturer shall complete the information document in accordance
with the items listed in Annex 8 and submit it to the responsible authority.
5.8. Contracting Parties may implement IUPR requirements set out in this UN GTR. In
case Contracting Parties implement IUPR requirements, they may either implement
the requirements of IUPR of greater than or equal to 0.1 directly or after the
implementation of IUPR demonstration set out in this UN GTR.
5.9. Contracting Parties may introduce the requirements of access to OBD information
set out in this UN GTR.
5.10. Notwithstanding Paragraph 5.7., Contracting Parties may choose not to introduce
the requirements of Administrative provisions set out in Annex 8 of this UN GTR.

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3.2. If available, the following signals in addition to the required freeze-frame information shall be
made available on demand through the serial port on the standardised diagnostic connector,
if the information is available to the on-board computer or can be determined using
information available to the on-board computer: diagnostic trouble codes, engine coolant
temperature, fuel control system status (closed-loop, open-loop, other), fuel trim, ignition
timing advance, intake air temperature, manifold air pressure, air flow rate, engine speed,
throttle position sensor output value, secondary air status (upstream, downstream or
atmosphere), calculated load value, vehicle speed and fuel pressure.
(a)
(b)
The signals shall be provided in standard units based on the specifications in
Paragraph 3.10. Actual signals shall be clearly identified separately from default value.
A Contracting Party may require in addition that actual signals shall be clearly identified
separately from limp-home signals.
3.3. For all control systems for which specific on-board evaluation tests are conducted (catalyst,
oxygen sensor, etc.) except, if applicable, misfire detection, fuel system monitoring and
comprehensive component monitoring, the results of the most recent test performed by the
vehicle and the limits to which the system is compared shall be made available through the
serial data port on the standardised diagnostic connector according to the specifications in
Paragraph 3.12. For the monitored components and systems excepted above, a pass/fail
indication for the most recent test results shall be available through the standardised
diagnostic connector.
All OBD in-use performance data that have to be stored under Paragraph 4.6. shall be made
available through the serial data port on the standardised diagnostic connector according to
the specifications in Paragraph 3.12.
3.4. The OBD requirements to which the vehicle is certified and the major control systems
monitored by the OBD system in accordance with the specifications in Paragraph 3.10. shall
be made available through the serial data port on the standardised diagnostic data link
connector according to the specifications in Paragraph 3.8.
3.5. The software identification number (Cal ID) and calibration verification numbers (CVN) shall
be made available through the serial port on the standardised diagnostic data link connector.
Both numbers shall be provided in a standardised format in accordance with the
specifications in Paragraph 3.10.
3.6. The diagnostic system is not required to evaluate components during malfunction if such
evaluation would result in a risk to safety or component failure.
3.7. The diagnostic system shall provide for standardised and unrestricted access to OBD and
conform with the following ISO Standards or SAE specification. Later versions may be used at
the manufacturers' discretion.

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3.12. The connection interface between the vehicle and the diagnostic tester shall be standardised
and meet all the requirements of ISO 19689:2016 "Motorcycles and Mopeds –
Communication between vehicle and external equipment for diagnostics – Diagnostic
connector and related electrical circuits, specification and use" or ISO 15031-3:2004 "Road
vehicles – Communication between vehicle and external test equipment for emissions-related
diagnostics – Part 3: Diagnostic connector and related electric circuits: specification and use".
The preferred installation position is under the seating position. Any other position of the
diagnostic connector shall be subject to the responsible authority's agreement and be readily
accessible by service personnel but protected from tampering by non-qualified personnel. The
position of the connection interface shall be clearly indicated in the user manual.
3.13. The vehicle manufacturer may use an alternative connection interface upon request. Where
an alternative connection interface is used, the vehicle manufacturer shall provide an adapter
enabling connection to a generic scan tool. Such an adapter shall be provided in a
non-discriminating manner to all independent operators.
4. EACH MONITOR OF THE OBD SYSTEM SHALL BE EXECUTED
4.1. General Requirements
4.1.1. Each monitor of the OBD system shall be executed at least once per driving cycle, in which
the monitoring conditions in Paragraph 5.3.11. of this regulation are met. Manufacturers shall
not use the calculated ratio (or any element thereof) or any other indication of monitor
frequency as a monitoring condition for any monitor.
4.1.2. The in-use performance ratio ('IUPR') of a specific monitor M of the OBD systems and in-use
performance of pollution control devices shall be:
Equation 1-1:
IUPR = NumeratorM/DenominatorM
4.1.3. Comparison of Numerator and Denominator gives an indication of how often a specific
monitor is operating relative to vehicle operation. To ensure all manufacturers are tracking
IUPRM in the same manner, detailed requirements are given for defining and incrementing
these counters.
4.1.4. The manufacturer shall demonstrate to the responsible authority the functionality of IUPR
determination.
If, in accordance with the requirements of this Annex, the vehicle is equipped with a specific
monitor M, IUPR shall be greater than or equal to 0.1 for all monitors M.
4.1.5. The requirements of this point are deemed to be met for a particular monitor M, if for all
vehicles of a particular vehicle and propulsion family manufactured in a particular calendar
year the following statistical conditions hold:
(a)
(b)
The average IUPR is equal or above the minimum value applicable to the monitor;
More than 50% of all vehicles have an IUPR equal or above the minimum value
applicable to the monitor.

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4.3.2. In addition to the requirements of Paragraph 4.3.1:
Secondary air system monitor denominator(s) shall be incremented if the commanded 'on'
operation of the secondary air system occurs for a time greater than or equal to 10s. For
purposes of determining this commanded 'on' time, the OBD system shall not include time
during intrusive operation of the secondary air system solely for the purposes of monitoring.
Denominators of monitors of systems only active during cold start shall be incremented if the
component or strategy is commanded 'on' for a time greater than or equal to 10s.
The denominator(s) for monitors of Variable Valve Timing (VVT) and/or control systems shall
be incremented if the component is commanded to function (e.g. commanded 'on', 'open',
'closed', 'locked', etc.) on two or more occasions during the driving cycle or for a time greater
than or equal to 10s, whichever occurs first.
For the following monitors, the denominator(s) shall be incremented by one if, in addition to
meeting the requirements of this point on at least one driving cycle, at least 800 cumulative
kilometres of vehicle operation have been experienced since the last time the denominator
was incremented:
(a)
(b)
Diesel oxidation catalyst;
Diesel particulate filter.
4.4. Ignition Cycle Counter
4.4.1. The ignition cycle counter indicates the number of ignition cycles a vehicle has experienced.
The ignition cycle counter may not be incremented more than once per driving cycle.
4.5. General Denominator
4.5.1. The general denominator is a counter measuring the number of times a vehicle has been
operated. It shall be incremented within 10s, if the following criteria are satisfied on a single
driving cycle:
(a)
(b)
(c)
Cumulative time since engine start is greater than or equal to 600s at an elevation of
less than 2,440m above sea level or an ambient pressure of more than 75.7kPa and an
ambient temperature of 266.2K (–7°C) or more;
Cumulative vehicle operation at or above 25km/h occurs for 300s or more at an
elevation of less than 2,440m above sea level or an ambient pressure of more than
75.7kPa and an ambient temperature of 266.2K (–7°C) or more;
Continuous vehicle operation at idle (i.e. accelerator pedal released by driver and
vehicle speed of 1.6km/h or less) for 30s or more at an elevation of less than 2,440m
above sea level or an ambient pressure of more than 75.7kPa and an ambient
temperature of 266.2K (–7°C) or more.
The general denominator may also be incremented outside the boundary conditions for
altitude or ambient pressure and ambient temperature.

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4.6.5. If either the numerator or denominator for a specific monitor reaches its maximum value, both
counters for that specific monitor shall be divided by two before being incremented again in
accordance with Paragraphs 4.2 and 4.3. If the ignition cycle counter or the general
denominator reaches its maximum value, the respective counter shall change to zero at its
next increment in accordance with Paragraphs 4.4 and 4.5 respectively.
4.6.6. Each counter shall be reset to zero only when a non-volatile memory reset occurs
(e.g. reprogramming event, etc.) 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 module (e.g. battery
disconnect, etc.).
4.6.7. The manufacturer shall take measures to ensure that the values of numerator and
denominator cannot be reset or modified, except in cases provided for explicitly in this point.
4.7. Disablement of Numerators and Denominators and of the General Denominator
4.7.1. Within 10s of detection of a malfunction which disables a monitor required to meet the
monitoring conditions of this Annex (i.e. a pending or confirmed code is stored), the OBD
system shall disable further incrementing of the corresponding numerator and denominator
for each monitor that is disabled. When the malfunction is no longer detected (i.e. the pending
code is erased through self-clearing or a scan tool command), incrementing of all
corresponding numerators and denominators shall resume within 10s.
4.7.2. Within 10s of the start of a power take-off unit (PTO) that disables a monitor required to meet
the monitoring conditions of this Annex, the OBD system shall disable further incrementing of
the corresponding numerator and denominator for each monitor that is disabled. When the
PTO operation ends, incrementing of all corresponding numerators and denominators shall
resume within 10s.
4.7.3. The OBD system shall disable further incrementing of the numerator and denominator of a
specific monitor within 10s, if a malfunction of any component used to determine the criteria
within the definition of the specific monitor's denominator (i.e. vehicle speed, ambient
temperature, elevation, idle operation, engine cold start or time of operation) has been
detected and the corresponding pending fault code has been stored. Incrementing of the
numerator and denominator shall resume within 10s when the malfunction is no longer
present (e.g. pending code erased through self-clearing or by a scan tool command).
4.7.4. The OBD system shall disable further incrementing of the general denominator within 10s if a
malfunction has been detected of any component used to determine whether the criteria in
Paragraph 4.5 are satisfied (i.e. vehicle speed, ambient temperature, elevation, idle operation
or time of operation) and the corresponding pending fault code has been stored. The general
denominator may not be disabled from incrementing for any other condition. Incrementing of
the general denominator shall resume within 10s when the malfunction is no longer present
(e.g. pending code erased through self-clearing or by a scan tool command).

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5.2.4. This information may be provided in the form of a table, as follows:
Table A1/1
Template OBD Information List
Component
Diagnostic trouble code
Monitoring strategy
Fault detection criteria
MI activation criteria
Secondary parameters
Preconditioning
Demonstration test
Default mode
Catalyst
P0420
Oxygen
sensor 1
and 2
signals
Difference
between
sensor 1
and sensor
2 signals
3rd cycle Engine speed,
engine load,
A/F mode,
catalyst
temperature
Two Type I
cycles
Type I
None
5.2.5. If a responsible authority receives a request from any interested components, diagnostic tools
or test equipment manufacturer for information on the OBD system of a vehicle that has been
certified by that responsible authority to a previous version of this Regulation (if any),
(a)
(b)
(c)
That responsible authority shall, within 30 days, ask the manufacturer of the vehicle in
question to make available the information required in Paragraphs 5.1. and 5.2.;
The vehicle manufacturer shall submit this information to that responsible authority
within two months of the request;
That responsible authority shall transmit this information to the other Contracting
Parties' responsible authorities and shall attach this information to the vehicle
certification information.
5.2.6. Information can be requested only for replacement or service components that are subject to
certification or for components that form part of a system subject to certification.
5.2.7. The request for repair information shall identify the exact specification of the vehicle model for
which the information is required. It shall confirm that the information is required for the
development of replacement or retrofit parts or components or diagnostic tools or test
equipment.

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ANNEX 2
MINIMUM MONITORING REQUIREMENTS FOR ELECTRIC CIRCUIT DIAGNOSTICS OF AN
ON-BOARD DIAGNOSTIC (OBD) SYSTEM
1. SUBJECT MATTER
The following minimum monitoring requirements shall apply for OBD systems regarding
electric circuit diagnostics.
2. SCOPE AND MONITORING REQUIREMENTS
(a)
(b)
If fitted, the following listed sensors and actuators shall be monitored for electric circuit
malfunctions which may cause emissions to exceed the designated OBD threshold
limits laid down to in Paragraph 5.5.1. of general requirements.
If fitted, a Contracting Party may require in addition that the following listed sensors and
actuators shall be monitored for electric circuit malfunctions which may lead to
activation of a default mode that results in a significant reduction of propulsion torque.
2.1. At a minimum the monitored devices with mandatory circuit diagnostics shall be the following:

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Table A2/1 (Cont'd)
No.
Device Circuits Circuit Continuity Circuit Rationality
Basic
monitoring
requirement
Comment
No.
Level, refer to 2.3.
Circuit High
Circuit Low
Open Circuit
Out of Range
Performance/
Plausibility
Signal stuck
Device not
operational/Device
not present
12
13
14
15
Intake air temperature
sensor
Knock sensor
(Non-resonance type)
Knock sensor
(Resonance type)
Manifold absolute
pressure sensor
1 Yes Yes Yes Yes Yes Yes
3 Yes
3 Yes
1 Yes Yes Yes Yes Yes Yes
16 Mass air flow sensor 1 Yes Yes Yes Yes Yes Yes
17
18
19
20
21
Engine oil temperature
sensor
O exhaust sensor
(binary/linear) signals
Fuel (high) pressure
sensor
Fuel storage
temperature sensor
Throttle position
sensor
1 Yes Yes Yes Yes Yes Yes
1 Yes Yes Yes Yes Yes Yes
1 Yes Yes Yes Yes Yes Yes
1 Yes Yes Yes Yes Yes Yes
1 Yes Yes Yes Yes Yes Yes
22 Vehicle speed sensor 3 Yes Yes
23 Wheel speed sensor 3 Yes Yes

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2.2. If there are more of the same device types fitted on the vehicle listed in Table A2/1 of
Annex 2, those devices shall be separately monitored and reported in case of malfunctions.
2.3. Sensors and actuators shall be associated with a specific diagnostic level that defines which
type of diagnostic monitoring shall be performed as follows:
2.3.1. Level 1: sensor/actuator of which at least two circuit continuity symptoms can be detected and
reported (i.e. short circuit to ground, short circuit to power and open circuit).
2.3.2. Level 2: sensor/actuator of which at least one circuit continuity symptom can be detected and
reported (i.e. short circuit to ground, short circuit to power and open circuit).
2.3.3. Level 3: sensor/actuator of which at least one symptom can be detected, but not reported
separately.
2.4. Two out of three symptoms in circuit continuity as well as in circuit rationality monitoring
diagnostic may be combined, e.g.
(a)
(b)
(c)
(d)
Circuit high or open and low circuit;
High and low or open circuit;
Signal out of range or circuit performance and signal stuck;
Circuit high and out of range high or circuit low and out of range low.
2.5. Exemptions Regarding Detection
Exemption from detecting certain electric circuit monitoring symptoms may be granted in the
following cases if the manufacturer can demonstrate to the satisfaction of the responsible
authority that:
2.5.1. A listed malfunction will not cause emissions to exceed the designated OBD threshold limits
set out in Paragraph 5.5.1. of general requirements; or
2.5.2. A listed malfunction will not cause a significant torque loss; or
2.5.3. The only feasible monitoring strategy would negatively affect vehicle functional safety or
driveability in a significant way.

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ANNEX 3
IN-USE PERFORMANCE RATIO
1. INTRODUCTION
1.1. This annex sets out the in-use performance ratio of a specific monitor M of the OBD systems
(IUPR M) requirements for vehicles in the scope of this UN GTR, certified in accordance with
this UN GTR.
2. AUDIT OF IUPR M
2.1. At the request of the responsible authority, the manufacturer shall report to the responsible
authority on warranty claims, warranty repair works and OBD faults recorded at servicing,
according to a format agreed at certification. The information shall detail the frequency and
substance of faults for emissions-related components and systems. The reports shall be filed at
least once in the vehicle's production cycle, for each vehicle model for the duration of 5 years of
age or the distance as specified in the durability test by the contracting party, whichever is
sooner.
2.2. Parameters Defining IUPR Family
For defining the IUPR family the OBD family parameters listed in Annex 5 shall be used.
2.3. Information Requirements
An audit of IUPR M will be conducted by the responsible authority on the basis of information
supplied by the manufacturer. Such information shall include in particular, the following:
2.3.1. The name and address of the manufacturer;
2.3.2. The name, address, telephone and fax numbers and e-mail address of his authorised
representative within the areas covered by the manufacturer's information;
2.3.3. The model name(s) of the vehicles included in the manufacturer's information;
2.3.4. Where appropriate, the list of vehicle types covered within the manufacturer's information,
i.e. for OBD and IUPR M, the OBD family in accordance with Annex 5;
2.3.5. The vehicle identification number (VIN) codes applicable to these vehicle types within the
family (VIN prefix);
2.3.6. The numbers of the certifications applicable to these vehicle types within the IUPR family,
including, where applicable, the numbers of all extensions and field fixes/recalls (re-works);
2.3.7. Details of extensions, field fixes/recalls to those certifications for the vehicles covered within the
manufacturer's information (if requested by the responsible authority);
2.3.8. The period of time over which the manufacturer's information was collected;

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3. SELECTION OF VEHICLES FOR IUPR M
3.1. The manufacturer's sampling shall be drawn from at least two different geographical regions
with substantially different vehicle operating conditions. Factors such as differences in fuels,
ambient conditions, average road speeds, and urban/highway driving split shall be taken into
consideration in the selection.
3.2. In selecting the geographical regions for sampling vehicles, the manufacturer may select
vehicles from a geographical region that is considered to be particularly representative. In this
case, the manufacturer shall demonstrate to the responsible authority which granted the
certification that the selection is representative (e.g. by the market having the largest annual
sales of a vehicle family within the Contracting Party). When a family requires more than one
sample lot to be tested as defined in Paragraph 3.3, the vehicles in the second and third
sample lots shall reflect different vehicle operating conditions from those selected for the first
sample.
3.3. Sample Size
3.3.1. The number of sample lots shall depend on the annual sales volume of an OBD family in the
Contracting Party, as defined in the following table:
Table A3/1
Number of Sample Lots
Contracting Party registrations
- per calendar year (for tailpipe emissions tests)
- of vehicles of an OBD family with IUPR in the sampling period
up to 100,000 1
100,001 to 200,000 2
above 200,000 3
Number of
sample
lots
3.3.2. For IUPR, the number of sample lots to be taken is described in the table in Paragraph 3.3.1.
(Table A3/1 of Annex 3) and is based on the number of vehicles of an IUPR family that are
certified with IUPR
For the first sampling period of an IUPR family, all of the vehicle types in the family that are
certified with IUPR shall be considered to be subject to sampling. For subsequent sampling
periods, only vehicle types which have not been previously tested or are covered by emissions
certifications that have been extended since the previous sampling period shall be considered
to be subject to sampling.
For families consisting of fewer than 5,000 Contracting Party registrations that are subject to
sampling within the sampling period, the minimum number of vehicles in a sample lot is six. For
all other families, the minimum number of vehicles in a sample lot to be sampled is 15.

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ANNEX 4
SELECTING CRITERIA FOR VEHICLES WITH RESPECT TO IN USE PERFORMANCE RATIOS
1. INTRODUCTION
1.1. This Annex sets out the criteria referred to in Section 4 of Annex 1 regarding the selection of
vehicles for testing and the procedures for IUPR M.
2. SELECTION CRITERIA
The criteria for acceptance of a selected vehicle are defined for IUPR M in Sections 2.1. to 2.5.
2.1. The vehicle shall belong to a vehicle type that is certified under this UN GTR. It shall be
registered and have been used in the territory of the Contracting Party.
2.2. The vehicle shall have been in service for at least 3,000km or 6 months, whichever the later,
and for no more than the durability mileages given for the relevant vehicles category mentioned
in the durability provisions specified by the contracting party or 5 years, whichever the sooner.
2.3. For checking IUPR M, the test sample shall include only vehicles that:
(a)
Have collected sufficient vehicle operation data for the monitor to be tested.
For monitors required to meet the in-use monitor performance ratio and to track and
report ratio data pursuant to Paragraph 4.6.1. of Annex 1, sufficient vehicle operation
data shall mean the denominator meets the criteria set forth below. The denominator, as
defined in Paragraphs 4.3 and 4.5 of Annex 1, for the monitor to be tested must have a
value equal to or greater than one of the following values:
(i)
(ii)
(iii)
15 for evaporative system monitors, secondary air system monitors, and monitors
utilising a denominator incremented in accordance with Paragraph 4.3.2. of
Annex 1 (e.g. cold start monitors, air conditioning system monitors, etc.); or
5 for particulate filter monitors and oxidation catalyst monitors utilising a
denominator incremented in accordance with Paragraph 4.3.2. of Annex 1; or
30 for catalyst, oxygen sensor, EGR, VVT, and all other component monitors.
(b)
Have not been tampered with or equipped with add-on or modified parts that would
cause the OBD system not to comply with the requirements of this regulation.
2.4. If any service has taken place, it shall be to the manufacturer's recommended service intervals.
2.5. The vehicle shall exhibit no indications of abuse (e.g. racing, overloading, mis-fuelling, or other
misuse), or other factors (e. g. tampering) that could affect emission performance. The fault
code and mileage information stored in the computer shall be taken into account. A vehicle
shall not be selected for testing if the information stored in the computer shows that the vehicle
has operated after a fault code was stored and a relatively prompt repair was not carried out.
2.6. There shall have been no unauthorised major repair to the engine or major repair of the
vehicle.

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3.6.6. A copy of the information transmitted to the vehicle owner.
3.6.7. A brief description of the system which the manufacturer uses to assure an adequate supply of
component or systems for fulfilling the remedial action. It shall be indicated when there will be
an adequate supply of components or systems to initiate the campaign.
3.6.8. A copy of all instructions to be sent to those persons who are to perform the repair.
3.6.9. A description of the impact of the proposed remedial measures on the emissions, fuel
consumption, driveability, and safety of each vehicle type, covered by the plan of remedial
measures with data, technical studies, etc. which support these conclusions.
3.6.10. Any other information, reports or data the responsible authority may reasonably determine is
necessary to evaluate the plan of remedial measures.
3.6.11. Where the plan of remedial measures includes a recall, a description of the method for
recording the repair shall be submitted to the responsible authority. If a label is used, an
example of it shall be submitted.
3.7. The manufacturer may be required to conduct reasonably designed and necessary tests on
components and vehicles incorporating a proposed change, repair, or modification to
demonstrate the effectiveness of the change, repair, or modification.
3.8. The manufacturer is responsible for keeping a record of every vehicle recalled and repaired
and the workshop which performed the repair. The responsible authority shall have access to
the record on request for a period of 5 years from the implementation of the plan of remedial
measures.
3.9. The repair and/or modification or addition of new equipment shall be recorded in a certificate
supplied by the manufacturer to the vehicle owner.

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1. INTRODUCTION
ANNEX 6
TEST TYPE VIII REQUIREMENTS: OBD ENVIRONMENTAL TESTS
1.1. This Annex describes the procedure for Type VIII testing on environmental On-Board
Diagnostics (OBD). The procedure describes methods for checking the function of the OBD
system on the vehicle by simulating failure of emission-relevant components in the powertrain
management system and emission-control system.
1.2. The manufacturer shall make available the defective components or electrical devices to be
used to simulate failures. When measured over the appropriate Test Type I cycle, such
defective components or devices shall not cause the vehicle emissions to exceed by more
than 20% the OBD threshold limits set out in Paragraph 5.5.1. of general requirements. For
failures (circuit continuity/circuit rationality/basic monitoring requirement), the emissions may
exceed the OBD threshold limits set out in Paragraph 5.5.1. of general requirements by more
than 20%.
1.3. When the vehicle is tested with the defective component or device fitted, the OBD system
shall be certified if the malfunction indicator is activated. The system shall also be certified if
the malfunction indicator is activated below the OBD threshold limits.
2. The test procedures in this Annex shall be mandatory for vehicles equipped with an OBD
system. This obligation concerns compliance with all provisions of this Annex.
3. DESCRIPTION OF TESTS
3.1. Test Vehicle
3.1.1. The environmental OBD verification and demonstration tests shall be carried out on a test
vehicle, that shall be properly maintained and used, dependent on the chosen durability test
method using the test procedures set-out in this Annex and in the applicable
World-harmonised Motorcycle Test Cycle (WMTC) set out in UN GTR No 2.
3.1.2. In case of applying the durability test procedure, the test vehicles shall be equipped with the
aged emission components used for durability tests as well as for the purposes of this Annex
and the OBD environmental tests shall be finally verified and reported at the conclusion of the
durability testing. At the request of the manufacturer, a suitable aged and representative
vehicle may be used for these OBD demonstration tests.
3.1.3. In case the OBD demonstration test requires emission measurements, the Type VIII test shall
be carried out on the test vehicles used for the durability test. Type VIII tests shall be finally
verified and reported at the conclusion of the durability testing.
3.1.4. In case of applying the fixed deterioration factors (DF) set out in GTR No.2, the applicable
deterioration factors shall be multiplied with the emission test results. If the responsible
authority allows, in case of misfire demonstration, alternatively experimentally determined
deterioration factors from the durability test may be used. This demo method may be used to
avoid damage during misfire testing to the deteriorated catalyst created by durability testing
and may be used on request of the manufacturer if it submits data and/or an engineering
evaluation which adequately demonstrates to the responsible authority the risk of damage to
the deteriorated catalyst.

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5. TEST VEHICLE AND TEST FUEL
5.1. Test Vehicle
5.3. Test Fuel
The test vehicles shall meet the requirements of UN GTR No. 2. The manufacturer shall set
the system or component for which detection is to be demonstrated at or beyond the criteria
limit prior to operating the vehicle over the emissions test cycle appropriate for the
classification of the vehicle. To determine correct functionality of the diagnostic system, the
test vehicle shall then be operated over the appropriate Type I test cycle according to its
classification set out in UN GTR No. 2.
The reference fuel to test the vehicle shall be specified by the Contracting Party and be of the
same specification as the reference fuel used to conduct the Type I tailpipe emissions after
cold start. The selected fuel type shall not be changed during any of the test phases.
6. TEST TEMPERATURE AND PRESSURE
6.1. The test temperature and ambient pressure shall meet the requirements of the Type I test as
set out in UN GTR No. 2.
7. TEST EQUIPMENT
Chassis dynamometer
7.1. The chassis dynamometer shall meet the requirements of UN GTR No. 2.
8. OBD ENVIRONMENTAL VERIFICATION TEST PROCEDURES
8.1. The operating test cycle on the chassis dynamometer shall meet the requirements of
UN GTR No. 2.
8.1.1. The Type I test need not be performed for the demonstration of electrical failures (short/open
circuit). The manufacturer may demonstrate these failure modes using driving conditions in
which the component is used and the monitoring conditions are encountered. Those
conditions shall be documented in the certification documentation.
8.2. Vehicle Preconditioning
8.2.1. According to the propulsion type and after introduction of one of the failure modes referred to
in Paragraph 8.3., the vehicle shall be preconditioned by driving at least two consecutive
appropriate Type I tests. For vehicles equipped with a compression ignition engine, additional
preconditioning of two appropriate Type I test cycles is permitted.
8.2.2. At the request of the manufacturer, alternative preconditioning methods may be used.
8.2.3. The use of additional preconditioning cycles or alternative preconditioning methods shall be
documented in the certification documentation.

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8.4. OBD System Environmental Verification Tests
8.4.1. Vehicles fitted with positive-ignition engines:
After vehicle preconditioning in accordance with Paragraph 8.2., the test vehicle is driven over
the appropriate Type I test.
8.4.1.1. The malfunction indicator shall activate before the end of this test under any of the conditions
given in Paragraphs 8.4.1.2. to 8.4.1.6. The MI may also be activated during preconditioning.
The responsible authority may substitute those conditions with others in accordance with
Paragraph 8.4.1.6. However, the total number of failures simulated shall not exceed four for
the purpose of certification.
8.4.1.2. Replacement of a catalytic converter type with a deteriorated or defective catalytic converter
or electronic simulation of a deteriorated or defective catalytic converter that results in
emissions exceeding the THC OBD threshold limit, or, if applicable, the NMHC OBD threshold
limit, in Paragraph 5.5.1. of general requirements, unless excluded from catalytic converter
monitoring by application of Paragraph 5.3.4. 2. of the general requirements;
8.4.1.3. An induced misfire condition in line with those for misfire monitoring referred to in
Paragraph 5.3.4.3. of general requirements that results in emissions of any components
exceeding any of the applicable OBD threshold limits given in Paragraph 5.5.1. of general
requirements;
8.4.1.4. Replacement of an oxygen sensor with a deteriorated or defective oxygen sensor or
electronic simulation of a deteriorated or defective oxygen sensor that results in emissions
exceeding any of OBD threshold limits in Paragraph 5.5.1. of general requirements;
8.4.1.5. Electrical disconnection of the electronic evaporative purge control device (if equipped);
8.4.1.6.
(a)
Electrical disconnection of any other emission-related powertrain component connected
to a powertrain control unit/engine control unit/drive train control unit that results in
emissions exceeding any of the OBD threshold limits in Paragraph 5.5.1. of general
requirements.
(b)
A Contracting Party may require in addition that triggers an operation mode with
significantly reduced torque as compared with normal operation.
8.4.2. Vehicles fitted with compression-ignition engines:
8.4.2.1. After vehicle preconditioning in accordance with Paragraph 8.2., the test vehicle is driven in
the applicable Type I test.
The malfunction indicator shall activate before the end of this test under any of the conditions
in Paragraphs 8.4.2.2. to 8.4.2.5. The responsible authority may substitute those conditions
by others in accordance with Paragraph 8.4.2.5. However, the total number of failures
simulated shall not exceed four for the purposes of certification;

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ANNEX 7
PROPULSION UNIT FAMILY DEFINITION WITH REGARD TO ON-BOARD DIAGNOSTICS
1. A vehicle in the scope of this UN GTR may continue to be regarded as belonging to the same
vehicle propulsion family with regard to on-board diagnostics provided that the vehicle parameters
in Table A7/1 or vehicle parameters referred to in Annex 5 are identical and remain within the
prescribed and declared tolerances.
2. A representative parent vehicle shall be selected within the boundaries set by the classification
criteria laid down in Table A7/1 or vehicle parameters referred to in Annex 5.
The following propulsion family classification criteria shall apply:
Table A7/1
Classification Criteria Propulsion Family with Regard to On-board Diagnostics
No.
Classification Criteria Description
1. VEHICLE
1.1.
Category;
X
Note: Two-wheeled motorcycles and two-wheeled motorcycles with
sidecars are considered to be of the same family.
1.2. sub-category; X
1.3. the inertia of a vehicle variant(s) or version(s) within two inertia categories
above or below the nominal inertia category;
1.4. overall gear ratios (+/- 8%). X
2. PROPULSION FAMILY CHARACTERISTICS
2.1. number of engines; X
2.2. number of cylinders of the combustion engine; X
2.3. engine capacity (+/- 30%) of the combustion engine; X
2.4. number and control (variable cam phasing or lift) of combustion engine
valves;
2.5. fuel system (carburettor/scavenging port/port fuel injection/direct fuel
injection/common rail/pump-injector/other);
X
X
X

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ANNEX 8
ADMINISTRATIVE PROVISIONS
1. The vehicle manufacturer shall fill out the information and submit to the responsible
authority with regard to functional on-board diagnostics and Test Type VIII according to
the following template.
1.1. Where documents, diagrams or long descriptions are required the vehicle manufacturer
shall attach those as a separate file, appropriately marked in a clear and understandable
system and the marking shall be written/typed for all sheets in the space provided.
1.2. The following data shall be provided by the vehicle manufacturer.
1.2.1. On-board Diagnostics (OBD) Functional Requirements
1.2.1.1. OBD System General Information
1.2.1.1.1. Written description and/or drawing of the Malfunction Indicator (MI);
1.2.1.1.2. List and purpose of all components monitored by the OBD system:
1.2.1.1.3. Written description (general working principles) for all OBD circuit (open circuit, shorted
low and high, rationality) and electronics (PCU/ECU internal and communication)
diagnostics:
1.2.1.1.4. Written description (general working principles) for all diagnostic functionality triggering
any operating mode which significantly reduces engine torque in case of fault detection;
1.2.1.1.5. Written description of the communication protocol(s) supported:
1.2.1.1.6. Physical location of diagnostic-connector (add drawings and photographs):
1.2.1.1.7. Written description in case of compliance with OBD (general working principles):
1.2.1.1.7.1. Positive-ignition engines
1.2.1.1.7.1.1. Catalyst monitoring:
1.2.1.1.7.1.2. Misfire detection:
1.2.1.1.7.1.3. Oxygen sensor monitoring:
1.2.1.1.7.1.4. Other components monitored by the OBD system:
1.2.1.1.7.2. Compression-ignition engines
1.2.1.1.7.2.1. Catalyst monitoring:
1.2.1.1.7.2.2. Particulate filter monitoring:
1.2.1.1.7.2.3. Electronic fuelling system monitoring:

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1.2.1.2.5. Description of Electronic Throttle Control (ETC) Diagnostic Fault Codes.
1.2.1.3. Communication Protocol Information
1.2.1.3.1. The following information shall be referenced to a specific vehicle make, model and
variant, or identified using other workable definitions such as VIN or vehicle and systems
identification:
1.2.1.3.2. Any protocol information system needed to enable complete diagnostics in addition to the
standards prescribed in Paragraph 3.8. of Annex 1., such as additional hardware or
software protocol information, parameter identification, transfer functions, "keep alive"
requirements, or error conditions;
1.2.1.3.3. Details of how to obtain and interpret all diagnostic trouble codes not in accordance with
the standards prescribed in Paragraph 3.11. of Annex 1;
1.2.1.3.4. A list of all available live data parameters including scaling and access information;
1.2.1.3.5. A list of all available functional tests including device activation or control and the means to
implement them;
1.2.1.3.6. Details of how to obtain all component and status information, time stamps, pending DTC
and freeze frames;
1.2.1.3.7. PCU/ECU identification and variant coding;
1.2.1.3.8. Details of how to reset service lights;
1.2.1.3.9. Location of diagnostic connector and connector details;
1.2.1.3.10. Engine code identification.
1.2.1.4. Test and Diagnosis of OBD Monitored Components
1.2.1.4.1. A description of tests to confirm its functionality, at the component or in the harness
1.2.2. On-board Diagnostics Environmental Test Type VIII Requirements
1.2.2.1. Details of test vehicle(s), its powertrain and pollution-control devices explicitly documented
and listed, emission test laboratory equipment and settings.
1.2.2.1.1. The manufacturer shall enter the emission laboratory test type VIII results TR TTVIIIx in
the tables below (both in mg/km and in % of OTx):
Test Type VIII OBD environmental results

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