ISO 14230-1:2012

INTERNATIONAL ISO
STANDARD 14230-1
Second edition
2012-06-01
Road vehicles — Diagnostic
communication over K-Line (DoK-Line) —
Part 1:
Physical layer
Véhicules routiers — Communication de diagnostic sur la ligne K (DoK-
Line) —
Partie 1: Couche physique
Reference number
©
ISO 2012
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ii © ISO 2012 – All rights reserved

Contents Page
Foreword .iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 1
4 Conventions . 2
5 Document overview . 2
6 Vehicle to external test equipment connection . 3
6.1 K- and L-line configurations . 3
6.2 Configuration requirements . 3
7 Signal and communication specifications . 4
7.1 Signal . 4
7.2 Communication specification . 5
8 Requirements of external test equipment . 5
8.1 Minimum functional requirements . 5
8.2 Electrical specifications . 6
9 Requirements of ECU . 7
9.1 Minimum functional requirements . 7
9.2 Input and output lines . 7
9.3 Electrical specifications . 7
9.4 Minimum functional capabilities . 8
10 Wiring requirements . 8
Bibliography . 9
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 14230-1 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 3, Electrical
and electronic equipment.
This second edition cancels and replaces the first edition (ISO 14230-1:1999), which has been technically revised.
ISO 14230 consists of the following parts, under the general title Road vehicles — Diagnostic communication
over K-Line (DoK-Line):
— Part 1: Physical layer
— Part 2: Data link layer
— Part 3: Application layer
— Part 4: Requirements for emission-related systems
iv © ISO 2012 – All rights reserved

Introduction
ISO 14230 has been established in order to define common requirements for vehicle diagnostic systems
implemented on K-Line (UART based) communication link, as specified in this part of ISO 14230.
To achieve this, it is based on the Open Systems Interconnection (OSI) Basic Reference Model in accordance
with ISO/IEC 7498-1 and ISO/IEC 10731, which structures communication systems into seven layers. When
mapped on this model, the services specified by ISO 14230 are broken down into the following.
a) Diagnostic services (layer 7), specified in ISO 14229-6, ISO 14229-1;
b) Presentation layer (layer 6):
— vehicle manufacturer specific,
— legislated OBD: specified in ISO 15031-2, ISO 15031-5, ISO 15031-6, SAE J1930-DA, SAE J1979-DA,
SAE J2012-DA,
— legislated WWH-OBD: specified in ISO 27145-2, SAE J1930-DA, SAE J1979-DA, SAE J2012-DA,
SAE J1939 Appendix C (SPNs), SAE J1939-73 Appendix A (FMIs);
c) Session layer services (layer 5):
— legislated OBD: specified in ISO 14229-2,
— legislated WWH-OBD: specified in ISO 14229-2;
d) Transport layer services (layer 4), specified in ISO 14230-2;
e) Network layer services (layer 3), specified in ISO 14230-2;
f) Data link layer (layer 2), specified in ISO 14230-4, ISO 14230-2;
g) Physical layer (layer 1), specified in ISO 15765-4, ISO 14230-1.
This breakdown is shown in Table 1.
Table 1 — Enhanced and legislated OBD diagnostic specifications applicable to the OSI layers
Vehicle
manufacturer Legislated OBD Legislated WWH-OBD
Applicability OSI 7 layer
enhanced (On-Board Diagnostics) (On-Board Diagnostics)
diagnostics
Application ISO 14229-1, ISO 14229-1,
ISO 15031-5
(layer 7) ISO 14229-6 ISO 27145-3
ISO 27145-2, SAE 1930-DA,
SAE J1979-DA, SAE J2012-
ISO 15031-2, ISO 15031-5,
Presentation vehicle manufacturer DA, SAE J1939:2011
ISO 15031-6, SAE J1930-DA,
(layer 6) specific Appendix C (SPNs),
SAE J1979-DA, SAE J2012-DA
SAE J1939-73:2010
Appendix A (FMIs)
Seven layers
Session (layer
according to ISO 14229-2
5)
ISO 7498-1 and
ISO/IEC 10731 Transport
(layer 4)
ISO 15765-4,
ISO 14230-2 ISO 15765-2
ISO 15765-2
Network (layer
3)
ISO 15765-4 ISO 27145-4
Data link
ISO 14230-2
ISO 15765-4,
(layer 2)
ISO 11898-1,
ISO 11898-1,
ISO 11898-2
Physical
ISO 11898-2
ISO 14230-1
(layer 1)
The application layer services covered by ISO 14229-6 have been defined in compliance with diagnostic
services established in ISO 14229-1 and ISO 15031-5, but are not limited to use only with them. ISO 14229-6
is also compatible with most diagnostic services defined in national standards or vehicle manufacturers’
specifications.
vi © ISO 2012 – All rights reserved

INTERNATIONAL STANDARD ISO 14230-1:2012(E)
Road vehicles — Diagnostic communication over K-Line (DoK-
Line) —
Part 1:
Physical layer
1 Scope
This part of ISO 14230 specifies the physical layer, based on ISO 9141, on which the diagnostic services will be
implemented. It is based on the physical layer described in ISO 9141-2, but expanded to allow for road vehicles
with either 12 V d.c. or 24 V d.c. voltage supply.
NOTE In this part of ISO 14230, values given in parentheses apply to 24 V d.c. systems.
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 7637-1, Road vehicles — Electrical disturbances from conduction and coupling — Part 1: Definitions and
general considerations
ISO 7637-2, Road vehicles — Electrical disturbances from conduction and coupling — Part 2: Electrical
transient conduction along supply lines only
ISO 14230-2, Road vehicles — Diagnostic communication over K-Line (DoK-Line) — Part 2: Data link layer
ISO 15031-2, Road vehicles — Communication between vehicle and external equipment for emissions-related
diagnostics — Part 2: Guidance on terms, definitions, abbreviations and acronyms
3 Terms, definitions, symbols and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 15031-2 and the following apply.
3.1.1
rise time
time taken for the voltage to change from 20 V /100 to 80 V /100, where V is the vehicle
B B B
battery voltage
3.1.2
fall time
time taken for the voltage to change from 80 V /100 to 20 V /100, where V is the vehicle
B B B
battery voltage
3.2 Abbreviated terms
C capacitance contribution of external test equipment and associated cables
TE
C capacitance contribution of on-board wiring
OBW
C capacitance contribution of electronic control unit
ECU
ECU electronic control unit
EMI electromagnetic interference
NRZ non-return to zero
V vehicle battery voltage
B
4 Conventions
This part of ISO 14230 is based on the conventions discussed in the OSI Service Conventions
(ISO/IEC 10731:1994) as they apply for communication services.
5 Document overview
Figure 1 illustrates the most applicable application implementations utilizing the DoK-Line protocol.
Enhanced
Emissions -
Diagnostics
related OBD
ISO 14229-1 UDS ISO 15031-5
ISO 14229-6
subset
Specification and Emissions-related
OSI Layer 7
UDSonK- Line
requirements OBD services
Application
ISO 15031-2, -5, -6
vehicle manufacturer
Emissions-related
OSI Layer 6
specific
OBD data definition
Presentation
ISO 14229-2 UDS
ISO 14229-2 UDS
1 : 1
Session layer
OSI Layer 5
Session layer services
services
Session
Standardized Service Primitive Interface
Diagnostic communication over K-Line protocol (DoK-Line )
OSI Layer 4
Transport
ISO 14230-2
DoK-line
OSI Layer 3
Network
Data link layer
ISO 14230-4
DoK-Line
Requirements for
emissions-related
OSI Layer 2
systems
Data Link
ISO 14230-1
DoK-line
OSI Layer 1
Physical
Physical layer
Figure 1 — Diagnostic communication over K-Line document reference according to OSI model
2 © ISO 2012 – All rights reserved

6 Vehicle to external test equipment connection
6.1 K- and L-line configurations
Vehicle ECUs which support the protocol described in ISO 14230 shall support either a one-wire (K line only)
or a two-wire (K and L) communication connection for diagnosis, test or maintenance. Vehicle battery voltage,
V , power ground and signal ground shall be provided by the ECU(s) or the vehicle to the tester.
B
Line K is a bidirectional line. It is used during initialization to convey address information or, in the case of fast
initialization, the wake-up pattern from the external test equipment to vehicle ECUs, simultaneously with the L
line. After conveying this information, the K line is used for all other diagnostic communications be
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