Road vehicles -- Implementation of World-Wide Harmonized On-Board Diagnostics (WWH-OBD) communication requirements

This part of ISO 27145 provides an overview of the structure and the partitioning of the different parts of ISO 27145 and shows the relationship between the parts. In addition, it outlines the use case scenarios where the ISO 27145 series is used. All terminology that is common throughout the ISO 27145 series is also outlined. ISO 27145 is intended to become the single communication standard for access to OBD-related information. To allow for a smooth migration from the existing communication standards to this future world-wide communication standard, the initial communication concept is based on the ISO 15765 series, i.e. Diagnostic communication over Control Area Network (DoCAN). The intention is for the future communication concept to be based on the ISO 13400 series, i.e. Diagnostic communication over Internet Protocol (DoIP) utilizing Ethernet. In view of the usage of standard network layer protocols, future extensions to optional physical layers (e.g. wireless) are possible. ISO 27145 has been extended to define the world-wide harmonized On-Board Diagnostics (OBD) communication standard. Based on the results of the initialization, the external test equipment determines which protocol and diagnostic services are supported by the vehicle's emissions-related system, i.e. — legislated OBD: ISO 15031 series (based on DoCAN), and — legislated WWH-OBD: ISO 27145 series (based on DoCAN and DoIP). IMPORTANT — Use cases deriving from country-specific implementation of Global

Véhicules routiers -- Mise en application des exigences de communication pour le diagnostic embarqué harmonisé à l'échelle mondiale (WWH-OBD)

General Information

Status
Published
Publication Date
13-Aug-2012
Current Stage
6060 - International Standard published
Start Date
05-Jun-2012
Completion Date
14-Aug-2012
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INTERNATIONAL ISO
STANDARD 27145-1
First edition
2012-08-15
Road vehicles — Implementation of
World-Wide Harmonized On-Board
Diagnostics (WWH-OBD) communication
requirements —
Part 1:
General information and use case definition
Véhicules routiers — Mise en application des exigences de
communication pour le diagnostic embarqué harmonisé à l’échelle
mondiale (WWH-OBD) — Partie 1: Informations générales et définition
de cas d’usage
Reference number
ISO 27145-1:2012(E)
ISO 2012
---------------------- Page: 1 ----------------------
ISO 27145-1:2012(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2012

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,

electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s

member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 27145-1:2012(E)
Contents Page

Foreword ............................................................................................................................................................................iv

0 Introduction ........................................................................................................................................................... v

0.1 Overview ................................................................................................................................................................ v

0.2 SAE document reference concept .................................................................................................................. v

0.3 SAE digital annex revision procedure .......................................................................................................... vi

1 Scope ...................................................................................................................................................................... 1

2 Normative references ......................................................................................................................................... 1

3 Terms, definitions and abbreviated terms .................................................................................................... 2

3.1 Terms and definitions ......................................................................................................................................... 2

3.2 Abbreviated terms ............................................................................................................................................... 3

4 Conventions .......................................................................................................................................................... 4

5 Document overview ............................................................................................................................................ 4

6 WWH-OBD use case overview ......................................................................................................................... 7

6.1 Overview ................................................................................................................................................................ 7

6.2 WWH-OBD use case clusters ........................................................................................................................... 7

7 WWH-OBD use case definition ........................................................................................................................ 8

7.1 UC 1 — Information about the emissions-related OBD system state ................................................... 8

7.2 UC 2 — Information about active and confirmed emissions-related malfunctions .......................... 9

7.3 UC 3 — Information related to diagnosis for the purpose of repair ....................................................10

8 Vehicle on-board diagnostic ......................................................................................................................... 11

8.1 VOBD definition ................................................................................................................................................ 11

8.2 The VOBD system ............................................................................................................................................. 11

8.3 The VOBD data set ............................................................................................................................................14

8.4 The VOBD access method ..............................................................................................................................14

Bibliography .....................................................................................................................................................................19

© ISO 2012 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 27145-1:2012(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies

(ISO member bodies). The work of preparing International Standards is normally carried out through ISO

technical committees. Each member body interested in a subject for which a technical committee has been

established has the right to be represented on that committee. International organizations, governmental and

non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International

Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards

adopted by the technical committees are circulated to the member bodies for voting. Publication as an

International Standard requires approval by at least 75 % of the member bodies casting a vote.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent

rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 27145-1 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 3, Electrical

and electronic equipment.

This first edition of ISO 21745-1 cancels and replaces ISO/PAS 27145-1:2006, which has been technically revised.

ISO 27145 consists of the following parts, under the general title Road vehicles — Implementation of World‑Wide

Harmonized On‑Board Diagnostics (WWH‑OBD) communication requirements:
— Part 1: General information and use case definition
— Part 2: Common data dictionary
— Part 3: Common message dictionary
— Part 4: Connection between vehicle and test equipment
The following parts are under preparation:
— Part 6: External test equipment
iv © ISO 2012 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 27145-1:2012(E)
0 Introduction
0.1 Overview

The ISO 27145 series includes the communication between the vehicle’s on-board diagnostics (OBD) systems

and external test equipment within the scope of the World-Wide Harmonized On-Board Diagnostics Global

Technical Regulations (WWH-OBD GTR).

It has been established in order to apply the unified diagnostic services (specified in ISO 14229-1) to

WWH-OBD systems.

The ISO 27145 series includes the communication between the vehicle’s WWH-OBD systems and external

(off-board) “generic” test equipment within the scope of the country-specific regulatory requirements.

To achieve this, it is based on the Open Systems Interconnection (OSI) Basic Reference Model specified

in ISO/IEC 7498-1 and ISO/IEC 10731, which structures communication systems into seven layers. Where

mapped on this model, the services specified by ISO 27145 are divided into

— diagnostic services (layer 7), specified in ISO 27145-3 with reference to ISO 14229-1,

— presentation layer (layer 6), specified in ISO 27145-2 with reference to SAE J1930-DA, SAE J1939 Companion

Spreadsheet (SPNs), SAE J1939-73:2010, Appendix A (FMIs), SAE J1979-DA and SAE J2012-DA,

— session layer services (layer 5), specified in ISO 14229-2,

— transport layer services (layer 4), specified in ISO 27145-4 with reference to ISO 13400-2, ISO 15765-2

and ISO 15765-4,

— network layer services (layer 3), specified in ISO 27145-4 with reference to ISO 15765-4, ISO 15765-2 and

ISO 13400-2,

— data link layer (layer 2), specified in ISO 27145-4 with reference to ISO 11898-1, ISO 11898-2, ISO 15765-4,

ISO 13400-3 and IEEE 802.3, and

— physical layer (layer 1), specified in ISO 27145-4 with reference to ISO 11898-1, ISO 11898-2, ISO 15765-4,

ISO 13400-3 and IEEE 802.3,
in accordance with Table 1.
Table 1 — WWH-OBD specification reference applicable to the OSI layers
Applicability OSI seven layer WWH-OBD reference
Application (layer 7) ISO 14229-1, ISO 27145-3
ISO 27145-2,
Presentation (layer 6) SAE J1930-DA, SAE J1939 Companion Spreadsheet (SPNs),
SAE J1939-73:2010, Appendix A (FMIs), SAE J1979-DA, SAE J2012-DA
Seven layers
according to
Session (layer 5) ISO 14229-2
ISO/IEC 7498-
Transport (layer 4)
ISO 15765-2 DoCAN, ISO 13400-2 DoIP
1 and ISO/
ISO 15765-4 DoCAN TCP and IP
IEC 10731
Network (layer 3)
ISO 27145-4
Data link (layer 2) ISO 11898-1 CAN DLL,
ISO 13400-3 DoIP,
ISO 11898-2 CAN HS,
IEEE 802.3
Physical (layer 1)
ISO 15765-4 DoCAN
0.2 SAE document reference concept

ISO 27145 makes reference to several SAE documents which contain the terms, data and diagnostic trouble

code (DTC) definitions.
© ISO 2012 – All rights reserved v
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ISO 27145-1:2012(E)

ISO 27145-2 defines a common data dictionary for the ISO 27145 series, according to the definitions in the

following documents (see Figure 1):

— SAE J1930-DA: this digital annex contains all standardized naming objects, terms and abbreviated terms.

— SAE J1939 Companion Spreadsheet and SAE J1939-73: SAE J1939 Companion Spreadsheet indexes

names for suspect parameter numbers (SPNs) that provide an alternative presentation format for

SAE J2012-DA DTCs. SPNs are combined with failure mode indicators (FMIs) to form the full alternative

presentation. FMIs are described in SAE J1939-73:2010, Appendix A.

NOTE The SAE J1939 Companion Spreadsheet is a document which supplements the SAE J1939 family of

standards and contains SPNs and parameter group numbers (PGNs).

— SAE J1979-DA: this digital annex contains all standardized data items such as data identifiers (DIDs), test

identifiers (TIDs), monitor identifiers (MIDs) and infotype identifiers (ITIDs).

— SAE J2012-DA: this digital annex contains all standardized data items such as DTC definitions and FTB

(failure type byte) definitions.
ISO 27145-2
WWH-OBD
common data dictionary
1 2
SAE J1930-DA
SAE J1939
digital annex of
SAE J1939-73:2010
SAE J2012-DA
[Companion
SAE J1979-DA electrical /electronic
[Appendix A]
digital annex of
Spreadsheet]
digital annex of E/E systems diagnostic
diagnostic trouble
diagnostic test modes terms, definitions,
code definitions
abbreviations and
acronyms
Key
1 SAE digital annexes: data definitions
2 SAE J1939 series of documents: DTC definitions
Figure 1 — SAE digital annex document reference
0.3 SAE digital annex revision procedure

New regulatory requirements drive new in-vehicle technology to lower emissions, improve safety, etc. It is

important to standardize new technology-related OBD monitor data and DTCs in order to support the external

(off-board) “generic” test equipment. All relevant information is proposed by the automotive industry, represented

by members of the appropriate SAE task force.

ISO 27145-2 references a “Change request form” for use with new data items to be defined by the SAE

task force for standardization. It is intended that the standardized data items be defined in SAE J1930-DA,

SAE J1979-DA, SAE J2012-DA and SAE J1939. It is intended that the documents be published on the SAE

store website once the information has been balloted and approved.
vi © ISO 2012 – All rights reserved
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ISO 27145-1:2012(E)

The revision request forms and instructions for updating the registers to ISO 27145 can be obtained on the

following data registration websites.

— For SAE J1930-DA: http://www.sae.org/servlets/works/committeeHome.do?comtID=TEVDS7

The column entitled “Resources” shows a document with the title: J1930-DA_Revision_Request_Form.

doc. Double click on the name to download the document with the filename: “SAE_J1930-DA_Revision_

Request_Form.doc”.
— For SAE J1939: http://www.sae.org/

Search “J1939 Request”, select “J1939 Request Processing Group”, and select “J1939 Request Processing

Form and Guidelines”.

— For SAE J1979-DA: http://www.sae.org/servlets/works/committeeHome.do?comtID=TEVDS14

The column entitled “Resources” shows a document with the title: J1979-DA_Revision_Request_Form.

doc. Double click on the name to download the document with the filename: “SAE_J1979-DA_Revision_

Request_Form.doc”.

— For SAE J2012-DA: http://www.sae.org/servlets/works/committeeHome.do?comtID=TEVDS9

The column entitled “Resources” shows a document with the title: J2012-DA_Revision_Request_Form.

doc. Double click on the name to download the document with the filename: “SAE_J2012-DA_Revision_

Request_Form.doc”.
It is intended that the revision request form be filled out with the request.

It is intended that e-mails with completed revision request forms as attachments be sent to:

E-mail: saej1930@sae.org
E-mail: saej1979@sae.org
E-mail: saej2012@sae.org
E-mail: saej1939@sae.org
© ISO 2012 – All rights reserved vii
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INTERNATIONAL STANDARD ISO 27145-1:2012(E)
Road vehicles — Implementation of World-Wide Harmonized
On-Board Diagnostics (WWH-OBD) communication
requirements —
Part 1:
General information and use case definition
1 Scope

This part of ISO 27145 provides an overview of the structure and the partitioning of the different parts of

ISO 27145 and shows the relationship between the parts. In addition, it outlines the use case scenarios where

the ISO 27145 series is used. All terminology that is common throughout the ISO 27145 series is also outlined.

ISO 27145 is intended to become the single communication standard for access to OBD-related information. To

allow for a smooth migration from the existing communication standards to this future world-wide communication

standard, the initial communication concept is based on the ISO 15765 series, i.e. Diagnostic communication

over Control Area Network (DoCAN).

The intention is for the future communication concept to be based on the ISO 13400 series, i.e. Diagnostic

communication over Internet Protocol (DoIP) utilizing Ethernet. In view of the usage of standard network layer

protocols, future extensions to optional physical layers (e.g. wireless) are possible.

ISO 27145 has been extended to define the world-wide harmonized On-Board Diagnostics (OBD) communication

standard. Based on the results of the initialization, the external test equipment determines which protocol and

diagnostic services are supported by the vehicle’s emissions-related system, i.e.

— legislated OBD: ISO 15031 series (based on DoCAN), and
— legislated WWH-OBD: ISO 27145 series (based on DoCAN and DoIP).

IMPORTANT — Use cases deriving from country-specific implementation of Global Technical

Regulation (GTR) No. 5 into local legislation are not included in this part of ISO 27145.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated

references, only the edition cited applies. For undated references, the latest edition of the referenced document

(including any amendments) applies.

ISO 14229-1, Road vehicles — Unified diagnostic services (UDS) — Part 1: Specification and requirements

ISO 14229-2, Road vehicles — Unified diagnostic services (UDS) — Part 2: Session layer services

ISO 27145-2, Road vehicles — Implementation of World‑Wide Harmonized On‑Board Diagnostics (WWH‑

OBD) communication requirements — Part 2: Common data dictionary

ISO 27145-3, Road vehicles — Implementation of World‑Wide Harmonized On‑Board Diagnostics (WWH‑

OBD) communication requirements — Part 3: Common message dictionary

ISO 27145-4, Road vehicles — Implementation of World‑Wide Harmonized On‑Board Diagnostics (WWH‑

OBD) communication requirements — Part 4: Connection between vehicle and test equipment

© ISO 2012 – All rights reserved 1
---------------------- Page: 8 ----------------------
ISO 27145-1:2012(E)
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions

For the purposes of this document, the terms and definitions in ISO 14229-1 and the following apply.

3.1.1
calibration identifier
CALID

identification code for a specific software/calibration contained in a server/ECU

NOTE If regulations require calibration identifications for emissions-related software, these are reported in a

standardized format as specified in ISO 27145-2.
3.1.2
class A, B1, B2, C malfunction

attribute of a DTC, which characterizes the impact of a failure on emissions or on the OBD system’s monitoring

capability according to the requirements of the WWH-OBD GTR
3.1.3
continuous malfunction indicator
continuous-MI

malfunction indicator showing a steady indication at all times while the key is in the on (run) position with the

engine running [ignition ON – engine ON]
3.1.4
continuous malfunction indicator counter
continuous-MI counter

conveys the amount of time the OBD system was operational during the time a continuous-MI was last activated

NOTE For a detailed definition, see GTR No. 5.
3.1.5
confirmed and active DTC

DTC status, which is detected during two consecutive operation cycles, in which the DTC is still present and

commands the MI to be on if the DTC class is A, B1 or B2
NOTE For a DTC of class C, the MI is not illuminated.
3.1.6
cumulative continuous malfunction indicator counter
cumulative continuous-MI counter
cumulated operating hours with a continuous-MI activated

NOTE The cumulative continuous-MI counter counts up to the maximum value provided in a 2-byte counter with 1 h

resolution and holds that value. The cumulative continuous-MI counter is not reset to zero by the engine system, a scan

tool or a disconnection of a battery.
The cumulative continuous-MI counter operates in the following manner:

a) the cumulative continuous-MI counter begins counting once the continuous-MI is activated;

b) the cumulative continuous-MI counter halts and holds its existing value once the continuous-MI is no

longer activated;

c) the cumulative continuous-MI counter continues counting from the point at which it had been held when a

continuous-MI was activated.
2 © ISO 2012 – All rights reserved
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ISO 27145-1:2012(E)
3.1.7
calibration verification number
CVN

server/ECU calculated verification number used to verify the integrity of the software/calibration contained

in a server/ECU

NOTE If regulations require calibration identifications for emissions-related software, those are reported in a standardized

format as specified in ISO 27145- 2.
3.1.8
discriminatory display

requires the MI to be activated according to the class in which a malfunction has been classified

3.1.9
malfunction

failure or deterioration of a vehicle or engine system or component, including the OBD system, during which the

WWH-OBD GTR specifically identifies the conditions which are considered to be failures

3.1.10
malfunction indicator

display or gauge that clearly informs the driver of the vehicle in the event of a malfunction/failure

NOTE Additional details are included in the WWH-OBD GTR.
3.1.11
malfunction indicator counter
MI counter

conveys the amount of time during which the OBD system operates while a failure/breakdown is active

3.1.12
non-discriminatory display
indicator requiring only a single type of MI activation
3.1.13
on-board diagnostics
OBD
system that monitors some or all computer input and control signals

NOTE Signal(s) outside of the predetermined limits imply a fault in the system or in a related system.

3.1.14
previously active DTC

DTC status that is first detected during two consecutive operation cycles but later detection shows that the fault

is no longer present
3.1.15
vehicle identification number
VIN

numeral identifying and specific and unique to each vehicle according to the applicable legal provisions of each

national/regional authority
3.1.16
vehicle on-board diagnostics

providing a single access point for external test equipment to retrieve all data of the OBD system

3.2 Abbreviated terms
CALID calibration identification
CVN calibration verification number
© ISO 2012 – All rights reserved 3
---------------------- Page: 10 ----------------------
ISO 27145-1:2012(E)
DTC diagnostic trouble code
DID diagnostic data identifier
DLL data link layer
ECM engine control module
ECU electronic control unit
FMI failure mode indicator
FTB failure type byte
GTR global technical regulations
HS high speed
HS-LPM high speed – low power mode
MI malfunction indicator
SPN suspect parameter number
UDS unified diagnostic services
VIN vehicle identification number
VOBD vehicle on-board diagnostics
WLAN wireless local area network
WWH-OBD world-wide harmonized on-board diagnostics

WWH-OBDonCAN world-wide harmonized on-board diagnostics on controller area network

WWH-OBDonIP world-wide harmonized on-board diagnostics on internet protocol
4 Conventions

The ISO 27145 series is based on the conventions discussed in the OSI Service Conventions (ISO/IEC 10731)

as they apply to diagnostic services.
5 Document overview
Figure 2 shows the reference documents for the ISO 27145 series.
The ISO 27145 series specifies or includes the following references.

a) This part of ISO 27145 specifies the general structure of the ISO 27145 series and the WWH-OBD GTR

applicable use cases.
b) ISO 27145-2 specifies the common data dictionary with references to:
1) SAE J1930-DA, which defines the terms, definitions, abbreviated terms, etc.;
2) SAE J1939 Companion Spreadsheet, which specifies the SPNs;
3) SAE J1939-73:2010, Appendix A, which specifies the FMIs;
4) SAE 1979-DA, which specifies all data items;
5) SAE J2012-DA, which specifies the DTC definitions and FTB definitions.
4 © ISO 2012 – All rights reserved
---------------------- Page: 11 ----------------------
ISO 27145-1:2012(E)

NOTE 1 The SAE J1939 series of documents is concerned with the definition of emissions-related SPNs and FMIs

for use as DTCs.

c) ISO 27145-3 specifies the diagnostic services defined in ISO 14229-1 that are applicable to WWH-OBD GTR.

d) ISO 14229-2 specifies the standardized service primitive interface to separate application and session

layers from protocol transport and network layers.
e) ISO 27145-4 specifies the initialization procedure and includes references to
1) ISO 15765-4 DoCAN, and
2) ISO 13400 (all parts) DoIP.

The ISO 27145 series provides an implementer with all documents and references required to support the

implementation of legislated on-board diagnostics in accordance with the requirements set forth in the GTR.

— This part of ISO 27145: general information and use case definitions, providing an overview of the series

along with the use case definitions and a common set of resources (definitions, references) for use by all

subsequent parts.

— ISO 27145-2: common data dictionary, which provides the general data identifier, ranges and record

definitions. The actual data are defined in separate/referenced documents, e.g. emissions-related

legislated diagnostics in the SAE digital annexes (see also Note 2).

— ISO 27145-3: common message dictionary, which provides the message implementation details from

ISO 14229-1 and ISO 14229-2 (UDS) to support the required legislated OBD.

— ISO 27145-4: connection between vehicle and test equipment, which defines the details necessary to

implement the communication between the vehicle’s OBD systems and test equipment, including the

definition/reference of physical layers, data link layers, network layer, transport layer and session layer. It is

expected to extend ISO 27145-4 as necessary due to the introduction of additional communication media.

— ISO 27145-5: conformance test, which provides test cases for the vehicle and external test equipment to

verify conformance.

— ISO 27145-6: external test equipment, which provides the requirements to be fulfilled by any external test

equipment connected to the vehicle.

NOTE 2 It is intended to introduce additional parts of ISO 27145 as necessary in order to consider additional OBD

systems not yet covered.
© ISO 2012 – All rights reserved 5
---------------------- Page: 12 ----------------------
ISO 27145-1:2012(E)
Unified diagnostic services (UDS)
ISO 27145-1
WWH-OBD
general information and
use case definition
ISO 27145-3
SAE J1930-DA
ISO 14229-1 UDS
1 : 1
WWH-OBD
subset Terms , ..
specification and
OSI layer 7
common message
requirements
Application
dictionary
SAE J1979-DA
1 : 1
PIDs, MIDs, RIDs,
ITIDs
ISO 27145-2
WWH-OBD
OSI layer 6
common data
Presentation
dictionary
SAE J2012-DA
1 : 1
WWH-OBD DTCs
SAE J1939 Companion
ISO 14229-2 UDS ISO 14229-2 UDS
1 : 1
OSI layer 5
Spreadsheet
session layer interfaces session layer interfaces
subset
Session SAE J1939-73:2011,
Appendix A
Standardized service primitive interface
Diagnostic communication over CAN and Internet Protocol
DoCAN
DoIP
OSI layer 4
Transport
ISO 15765-2 DoCAN
ISO 13400-2 DoIP
transport protocol
transport protocol
and
and
network
network
layer services
layer services
OSI layer 3
Network
ISO 27145-4
ISO 15765-4 DoCAN
WWH-OBD
requirements for
emissions-related connection between
systems vehicle and test
equipment
OSI layer 2
ISO 11898-1 CAN
Data link
data link layer
ISO 13400-3 DoIP
and physical signalling
wired vehicle
interface based
ISO 11898-2 CAN
on IEEE 802.3
high-speed
medium access unit
OSI layer 1
Physical
Figure 2 — Implementation of WWH-OBDonCAN and WWH-OBDonIP document reference
according to OSI model
6 © ISO 2012 – All rights reserved
---------------------- Page: 13 ----------------------
ISO 27145-1:2012(E)
6 WWH-OBD use case overview
6.1 Overview

The OBD system is required to make available vehicle diagnostic information under several different use cases

as specified by the GTR. These use cases provide the implementer with guidance in the implementation of

the VOBD (described in Clause 8), and methodology used on the vehicle to make the required data available.

NOTE WWH-OBD GTR No. 5 defines the basis for world-wide harmonized regulatory requirements. Translation of

GTR No. 5 into country-specific regulatory language can define additional use cases.

6.2 WWH-OBD use case clusters
The following is a summary of the use cases applicable to WWH-OBD systems.

Table 2 provides an overview of the main WWH-OBD use cases. A main WWH-OBD use case cluster may

have one or more use case definition(s).
Table 2 — WWH-OBD main use case clusters
No. Main title of use case cluster Brief description

1 Information about the The purpose of this information package is to provide the minimum data

emissions-related OBD system set specified as necessary by the WWH-OBD GTR to obtain the vehicle or

state engine state with respect to its emissions performance, as specified in the

GTR. A typical use of this information package may be a “roadside check”
performed by an enforcement authority.

2 Information about active The purpose of this information package is to provide access to the

emissions-related malfunctions expanded data set specified as necessary by the WWH-OBD GTR to

determine vehicle readiness and characterize the malfunctions detected
by the OBD system. A typical use of this information package may be a
periodic inspection by enforcement authorities.

3 Information related to diagnosis The purpose of this information package is to provide access to all OBD

for the purpose of repair data required by the WWH-OBD GTR and available from the OBD system.

A typical use of this information package may be the diagnostic servicing of
the vehicle or system in a workshop environment.

Detailed definitions of each data item listed in the use cases can be found in the emissions-related module of

the WWH-OBD GTR.
© ISO 2012 – All rights reserved 7
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ISO 27145-1:2012(E)
7 WWH-OBD use case definition
7.1 UC 1 — Information about the emissions-related OBD system state

Table 3 specifies the data set to be supported by the emissions-related VOBD system.

Table 3 — UC 1 Information about the emissions-related OBD system state
Actor Enforcement agency

Goal This use case provides an enforcement agency with the malfunction indication (MI) status and

associated vehicle system data (e.g. MI counter, readiness status, etc.).

Use case input Broadcast request message to retrieve the emissions-related WWH-OBD system state.

Use case output — Discriminatory/non-discriminatory display strategy
— The VIN (vehicle identification number)
— Presence of a continuous-MI
— The readiness status of the OBD system

— The number of engine operating hours during which a continuous-MI was last activated

(continuous-MI counter)

— This information shall be read-only access (i.e. no clearing) within the context of

...

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