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

ISO 27145-2:2012 defines all regulatory data elements of the ISO 27145 series. The data elements are used to provide the external test equipment with the diagnostic status of the vehicle on-board diagnostics (VOBD) system in the vehicle. All data elements are communicated with the unified diagnostic services as defined in ISO 27145-3. The data elements are diagnostic trouble codes (DTCs), data identifiers (DIDs) and routine identifiers (RIDs). The mapping from parameter identifiers (PIDs), monitor identifiers (MIDs) and info type identifiers (ITIDs) is described in ISO 27145-2:2012. If new legislated WWH-OBD GTR modules are established, it is intended that ISO 27145 be applicable with possible extensions, which can be included in ISO 27145-2:2012, can be specified as enhancements of the SAE Digital Annexes or can even be part of other referenced documents which are intended to include the applicable data definitions. ISO 27145 is intended to become the single communication standard for access to OBD-related information (VOBD). To allow for a smooth migration from the existing communication standards to this future world-wide communication standard, the communication concept as specified in ISO 27145-4 is based on two different data links: ISO 15765-4 and ISO 13400 (all parts).

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
26-Jun-2012
Completion Date
14-Aug-2012
Ref Project

RELATIONS

Buy Standard

Standard
ISO 27145-2:2012 - Road vehicles -- Implementation of World-Wide Harmonized On-Board Diagnostics (WWH-OBD) communication requirements
English language
34 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 27145-2
First edition
2012-08-15
Road vehicles — Implementation of
World-Wide Harmonized On-Board
Diagnostics (WWH-OBD) communication
requirements —
Part 2:
Common data dictionary
Véhicules routiers — Mise en application des exigences de
communication pour le diagnostic embarqué harmonisé à l'échelle
mondiale (WWH-OBD) —
Partie 2: Dictionnaire de données communes
Reference number
ISO 27145-2:2012(E)
ISO 2012
---------------------- Page: 1 ----------------------
ISO 27145-2:2012(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 27145-2:2012(E)
Contents Page

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

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

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

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

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

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

3.2  Abbreviated terms ................................................................................................................................. 4

4  Conventions ........................................................................................................................................... 5

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

6  Common data dictionary requirements .............................................................................................. 7

6.1  Data range layout .................................................................................................................................. 7

6.2  Diagnostic trouble code (DTC) range layout ...................................................................................... 7

7  Data identifier and routine identifier data record requirements ....................................................... 8

7.1  Data identifier and routine identifier definitions ................................................................................ 8

7.2  DID and RID data record definition ...................................................................................................... 8

8  Diagnostic trouble code definition .................................................................................................... 14

8.1  Overview ............................................................................................................................................... 14

8.2  SAE J2012-DA and SAE J1939-73 DTCs ........................................................................................... 15

9  Presentation layer requirements ....................................................................................................... 18

Annex A (normative) DID (PID, MID, ITID) and RID supported definition .................................................... 19

Annex B (normative) WWH-OBD server/ECU supported mandatory DID ................................................... 22

Annex C (informative) GTR WWH-OBD emissions system parameters ...................................................... 23

Annex D (normative) GTR WWH-OBD DTCExtendedDataRecord content ................................................. 30

Annex E (informative) Definition guidelines for new DID (PID, MID, ITID) assignments ........................... 31

Bibliography ...................................................................................................................................................... 34

© ISO 2012 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 27145-2:2012(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 27145-2 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 3,

Electrical and electronic equipment.

This first edition of ISO 27145-2 cancels and replaces ISO/PAS 27145-2:2006, 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 27145-2:2012(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 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 this part of ISO 27145 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
This part of ISO 27145,
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 7498-1
Transport (layer 4)
and
ISO 15765-2 DoCAN, ISO 13400-2 DoIP
ISO/IEC 10731
ISO 15765-4 DoCAN TCP and IP
Network (layer 3)
ISO 27145-4
ISO 11898-1 CAN DLL,
Data link (layer 2)
ISO 13400-3 DoIP,
ISO 11898-2 CAN HS,
IEEE 802.3
ISO 15765-4 DoCAN
Physical (layer 1)
© ISO 2012 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO 27145-2:2012(E)
0.2 SAE document reference concept

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

trouble code (DTC) definitions.

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 abbreviations.

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

names for suspect parameter numbers (SPNs), which 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 PGNs.

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

identifiers (TIDs), monitor identifiers (MIDs) and info type identifiers (ITIDs).

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

type byte (FTB) 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 diagnostic trouble codes 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.

This part of ISO 27145 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
---------------------- Page: 6 ----------------------
ISO 27145-2:2012(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
---------------------- Page: 7 ----------------------
INTERNATIONAL STANDARD ISO 27145-2:2012(E)
Road vehicles — Implementation of World-Wide Harmonized
On-Board Diagnostics (WWH-OBD) communication
requirements —
Part 2:
Common data dictionary
1 Scope

This part of ISO 27145 defines all regulatory data elements of the ISO 27145 series. The data elements are

used to provide the external test equipment with the diagnostic status of the vehicle on-board diagnostics

(VOBD) system in the vehicle. All data elements are communicated with the unified diagnostic services as

defined in ISO 27145-3. The data elements are diagnostic trouble codes (DTCs), data identifiers (DIDs) and

routine identifiers (RIDs). The mapping from parameter identifiers (PIDs), monitor identifiers (MIDs) and info

type identifiers (ITIDs) is described in this part of ISO 27145.

If new legislated WWH-OBD GTR modules are established, it is intended that ISO 27145 be applicable with

possible extensions, which can be included in this part of ISO 27145, can be specified as enhancements of

the SAE Digital Annexes or can even be part of other referenced documents which are intended to include the

applicable data definitions.

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

(VOBD). To allow for a smooth migration from the existing communication standards to this future world-wide

communication standard, the communication concept as specified in ISO 27145-4 is based on two different

data links: ISO 15765-4 and ISO 13400 (all parts).

In view of the usage of standard network layer protocols, future extensions to optional physical layers (e.g.

wireless) are possible.

NOTE It is expected to extend ISO 27145-4 as necessary upon introduction of additional communication media.

ISO 27145-4 is the entry point to establish communication with the vehicle. 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, and
 legislated WWH-OBD: ISO 27145.

Vehicles according to ISO 27145 provide VOBD system support as envisioned for WWH-OBD by Global

Technical Regulation (GTR) No. 5.

IMPORTANT — Use cases deriving from country-specific implementation of GTR No. 5 into local

legislation are not included in this part of ISO 27145.
© ISO 2012 – All rights reserved 1
---------------------- Page: 8 ----------------------
ISO 27145-2:2012(E)
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.
1 )

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 interfaces

ISO 27145-1, Road vehicles — Implementation of World-Wide Harmonized On-Board Diagnostics (WWH-

OBD) communication requirements — Part 1: General information and use case definition

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

SAE J1939, Companion Spreadsheet
SAE J1939-73:2010, Application layer — Diagnostics
SAE J1979-DA, Digital Annex of E/E Diagnostic Test Modes

SAE J2012-DA, Digital Annex of Diagnostic Trouble Code Definitions and Failure Type Byte Definitions

3 Terms, definitions and abbreviated terms
3.1 Terms and definitions

For the purposes of this document, the following terms and definitions given in ISO 27145-1 and ISO 14229-1

apply.
3.1.1
calibration identifier
CALID
identification code for the software installed in the electronic control unit
3.1.2
calibration verification number
CVN

server/ECU calculated verification number used to verify the integrity of the software in the electronic control

unit
3.1.3
central gateway
CGW
electronic control unit that connects in-vehicle communication networks
3.1.4
data identifier
DID
indicator making reference to a data item in the server
To be published. (Revision of ISO 14229-1:2006)
2 © ISO 2012 – All rights reserved
---------------------- Page: 9 ----------------------
ISO 27145-2:2012(E)
3.1.5
diagnostic trouble code
DTC
value making reference to a specific fault in a system implemented in the server

NOTE It is defined in SAE J2012-DA or as SPN and FMI as defined in SAE J1939 Companion Spreadsheet and

SAE J1939-73:2010, Appendix A.
3.1.6
info type identifier
ITID
indicator making reference to identification information
EXAMPLE Calibration identifier in the server.
NOTE The ITIDs are defined in SAE J1979-DA.
3.1.7
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.
3.1.8
monitor identifier
MID
indicator making reference to an OBD monitor function

NOTE An example of an OBD monitor function is a misfire monitor in the server. The MID is defined in

SAE J1979-DA.
3.1.9
standard/manufacturer monitor test identifier
SMTID
OBD identifier which is defined in SAE J1979-DA or by the vehicle manufacturer
3.1.10
parameter identifier
PID
unique identifier used to refer to a specific data value within a server
3.1.11
routine identifier
RID
identifier making reference to a routine function

NOTE 1 An example of a routine function is an evaporation monitor routine in the server.

NOTE 2 Routine identifiers are defined in SAE J1979-DA.
3.1.12
suspect parameter number
SPN

numeral that identifies a particular element, a fault associated with a component, such as a sensor, or a

parameter associated with an ECU
© ISO 2012 – All rights reserved 3
---------------------- Page: 10 ----------------------
ISO 27145-2:2012(E)
3.1.13
uniform resource locator
URL

uniform resource identifier which, in addition to identifying a resource, provides a means of locating the

resource by describing its primary access mechanism
NOTE An example of primary access mechanism is its network location.
3.2 Abbreviated terms
CALID calibration identification
CAN controller area network
CGW central gateway
CM conversion method
CVN calibration verification number
DID data identifier
DoCAN diagnostics communication over controller area network
DoIP diagnostics communication over internet protocol
DP data parameter
DP_DB data parameter data byte
DTC diagnostic trouble code
ECM engine control module
ECU electronic control unit
ECUNAME electronic control unit name
EVAP evaporative system
FMI failure mode indicator
FTB failure type byte
GTR global technical regulation
ITID info type identifier
IUPT in-use performance tracking
ITP info type parameter
ITP_DB info type parameter data byte
MI malfunction indicator
MID monitor identifier
Mod module
MP monitor parameter
MP_DB monitor parameter data byte
N/A not applicable
OC occurrence count
Param parameter
PID parameter identifier
req requirement
RID routine identifier
4 © ISO 2012 – All rights reserved
---------------------- Page: 11 ----------------------
ISO 27145-2:2012(E)
RP_DB routine parameter data byte
SF sub-function
SID service identifier
SMTID standard/manufacturer monitor test identifier
SPN suspect parameter number
URL uniform resource locator
VIN vehicle identification number
VOBD vehicle on-board diagnostics
WWH-OBD world-wide harmonized on-board diagnostics
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) ISO 27145-1 specifies the general structure of the ISO 27145 series and the WWH-OBD GTR applicable

use cases.

b) This part of ISO 27145 specifies the common data dictionary with references to the following documents:

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 J1979-DA, which specifies all data items;
5) SAE J2012-DA, which specifies the DTC definitions and FTB definitions.

NOTE The SAE J1939 series of documents are 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.
© ISO 2012 – All rights reserved 5
---------------------- Page: 12 ----------------------
ISO 27145-2:2012(E)
Unified diagnostic services (UDS)
ISO 27145-1
WWH-OBD
general information and
use case definition
ISO 27145-3
ISO 14229-1 UDS SAE J1930-DA
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
vehicle and test
systems
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 — Reference documents for implementation of WWH-OBDonCAN and WWH-OBDonIP

according to the OSI model
6 © ISO 2012 – All rights reserved
---------------------- Page: 13 ----------------------
ISO 27145-2:2012(E)
6 Common data dictionary requirements
6.1 Data range layout
This subclause specifies the reserved ranges for DIDs and RIDs.
IMPORTANT — DIDs and RIDs do not share the same 2-byte range.
ISO 14229-1 reserves the DID/MID/ITID/RID ranges.
6.2 Diagnostic trouble code (DTC) range layout

This subclause specifies the data range layout for DTCs, which is backward compatible to the existing

standards:

 the DTC definition in SAE J2012-DA for all BaseDTCs and FailureTypeBytes (FTB);

 the DTC definition in SAE J1939 Companion Spreadsheet (SPN), and SAE J1939-73:2010, Appendix A

(FMI).

This part of ISO 27145 defines a 3-byte DTC range, which consists of a BaseDTC number and a

FailureTypeByte (FTB), both defined in SAE J2012-DA, or an SPN and an FMI, both defined in SAE J1939

Companion Spreadsheet (SPN) and SAE J1939-73:2010, Appendix A.
Figure 3 depicts an overview of the DTC range definitions.
LSB
MSB
SAE J2012-DA 16 bits WWH -OBD BaseDTC Number (SAE J2012-DA WWH-OBD) 8 bits FTB
ISO 27145-2 DTCHighByte DTCMiddleByte DTCLowByte
SAE J1939 Three most
Eight least significant bits of SPN Second byte of SPN significant 5 bits FMI
Companion
bits of SPN
Spreadsheet
Figure 3 — Overview of the DTC range definitions

Table 2 provides an overview of the available DTC range as specified in SAE J2012-DA and SAE J1939

Companion Spreadsheet (SPN) and SAE J1939-73:2010, Appendix A (FMI).
Table 2 — WWH-OBD DTC ranges as defined in this part of ISO 27145
DTC range BaseDTC range FTB/FMI range DTC mnemonic Description
0x000000
16 8
16 bits = 2 -1 = FTB: 8 bits 2 = SAE_J2012-DA_ DTCs as defined in
65535 256 DTCFormat_04 SAE J2012-DA WWH-OBD
0xFFFFFF
SPNs as defined in SAE J1939,
0x000000 19 5 Companion Spreadsheet,
19 bits = 2 -1 = FMI: 5 bits 2 =
– SAE_J1939-73_DTCFormat and FMIs as defined in
524287 32
0xFFFFFF SAE J1939-73:2010,
Appendix A
© ISO 2012 – All rights reserved 7
---------------------- Page: 14 ----------------------
ISO 27145-2:2012(E)
7 Data identifier and routine identifier data record requirements
7.1 Data identifier and routine identifier definitions
7.1.1 ISO 14229-1 and SAE J1979-DA DID/RID mapping

The DIDs and RIDs are of different size depending on the specification from which they derive:

 SAE J1979-DA specifies 1-byte DIDs (PIDs, MIDs, ITIDs) and RIDs;
 ISO 14229-1:—, Annex C, supports 2-byte DIDs and RIDs.

Figure 4 shows how the 2-byte data identifier and routine identifier are defined based on the SAE J1979-DA

specification.

The "low byte" of the 2-byte identifier is derived from the 1-byte SAE J1979-DA defined identifiers. The "high

byte" of the 2-byte data identifier is defined in ISO 14229-1.
ISO 27145-2
High Byte Low Byte
XX XX
ISO 14229-1:—,
SAE J1979-DA
Annex C
Figure 4 — 2-byte DID and RID assembly
7.1.2 DID (PID, MID and ITID) and RID-supported definition

The vehicle system supports a subset of DID (PID, MID, ITID) and RID based on the emissions regulation to

which the vehicle shall comply.

The concept of supporting DIDs (PIDs, MIDs, ITIDs) is carried out with service ReadDataByIdentifier with the

DID (PID, MID, ITID) (low byte = 0x00/0x20/0x40/0x60/0x80/0xA0/0xC0) as specified in SAE J1979-DA.

The concept of supporting RIDs is carried out with service RoutineControl with the RID (low byte = 0x00) as

specified in SAE J1979-DA.
7.2 DID and RID data record definition
7.2.1 Supported data types
7.2.1.1 General

The message format as specified in ISO 27145-3 uses a 2-byte DID in service ReadDataByIdentifier as a

label for a dataRecord[] including the data parameters, e.g. PID data, MID data, ITID data.

8 © ISO 2012 – All rights reserved
---------------------- Page: 15 ----------------------
ISO 27145-2:2012(E)

The message format as specified in ISO 27145-3 uses a 2-byte RID in service RoutineControl as a label for a

routineStatusRecord[] including the data parameters, e.g. RID data.

A data parameter can either be of status type (discrete) or of measured type (analogue).

Status specifies the present state of a multi-state parameter or function as a result of action taken by the

transmitting server. This action is the result of a calculation, which uses local and/or network "measured" and

"status" information.

EXAMPLE 1 Status-type data are: engine brakes are enabled, cruise control is active, the cruise control is in the "set"

state of operation (as opposed to a measured indication that the "set" switch contacts are closed), diagnostic trouble

codes, torque/speed control override modes, desired speed/speed limit, engine torque mode, engine's desired operating

speed, engine's operating speed asymmetry adjustment, etc..

Measured data convey the current value of a parameter as measured or observed by the transmitting server

to determine the condition of the defined parameter.

EXAMPLE 2 Measured-type data are: boost pressure, ignition on/off, cruise set switch activated, maximum cruise

speed, cruise set speed, engine speed, % load at current speed, etc..

A RoutineControl can be either to request which routines are implemented in the server or to request that the

server
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.