ISO/FDIS 4009

ISO/DISFDIS 4009:2025(en)
ISO/TC 22/SC 40
Secretariat: UNI
Fourth edition
Date: 2025-0611-13
Commercial vehicles — Location of electrical and pneumatic
connections between towing vehicles and trailers
Véhicules utilitaires — Emplacement des connexions électriques et pneumatiques entre véhicules tracteurs et
véhicules remorqués
FDIS stage
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ISO/DISFDIS 4009:2025(en)
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Connection locations . 2
5 Connection dimensions . 9
6 Clearance space . 10
7 Flexible pipes of electrical and pneumatic connections . 10
7.1 Locations . 10
7.2 Length. 10
Annex A (normative) The arrangement of the connectors . 13
Bibliography . 15

iii
Foreword
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 40, Specific
aspects for passenger cars, light and heavy commercial vehicles, bussesspecial vehicles, buses and
trailers/caravans.
This fourth edition cancels and replaces the third edition (ISO 4009:2000), which has been technically revised.
The main changes are as follows:
— — multiple-vehicle combinations have been added to the Scopescope;
— — new connectors have been added in Figure 1Figure 1 to Figure 4Figure 4;;
— — the arrangement of the connectors has been changed in Figure 1Figure 1 to Figure 4Figure 4;;
— — general requirement for the length of flexible pipes has been added;
— — the arrangement of the connectors has been added in a new Annex AAnnex A;;
— — editorial changes have been made.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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ISO/DISFDIS 4009:2025(en)
Introduction
Standardization requirements for the arrangement of electrical and pneumatic connections between towing
vehicles and trailers are crucial to ensure seamless connectivity, operational safety, and the reliable
functioning of vehicle combinations. As vehicle technology advances rapidly and an increasing variety of
vehicles enter transportation market, more standardized requirements have been proposed for the
arrangement of these connections. For instance, some vehicles allow the upper and lower mounting surfaces
of connectors to be integrated into a single plane. Unifying the arrangement of connectors for drawbar-trailers
and centre-axle trailers would further improve operational convenience. Some pipelines are installed at low
positions, making them prone to ground contact and abrasion, so adding protective measures is beneficial for
the pipelines. Additionally, incorporating schematic diagrams of connector layouts in this standard enhances
its practicality.
Therefore, it is necessary to further explore ways to enhance the interchangeability between tractors and
trailers, standardize the arrangement of connections, and ensure the safe operation of vehicle combinations
must be explored.
v
DRAFT International Standard ISO/DIS 4009:2025(en)

Commercial vehicles — Location of electrical and pneumatic
connections between towing vehicles and trailers
1 Scope
This document specifies the locations of coupling devices for electrical and pneumatic connections between
towing and towed commercial road vehicles. It is applicable to heavy vehicles equipped with pneumatic
braking systems and 24 V electrical equipment of the following types: drawbar-trailer combinations, centre-
axle trailer combinations and multiple-vehicle combinations whose towing vehicles or trailers have
rear--mounted couplings or couplings mounted forward and below, and articulated vehicles.
This document is not applicable to car carriers, or road vehicles equipped only with fully automatic coupling
system (FACS) according to the ISO 13044 series, not mounted on the front of the trailer.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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 1185, Road vehicles — Connectors for the electrical connection of towing and towed vehicles — 7-pole
connector type 24 N (normal) for vehicles with 24 V nominal supply voltage
ISO 1728, Road vehicles — Pneumatic braking connections between motor vehicles and towed vehicles —
Interchangeability
ISO 3731, Road vehicles — Connectors for the electrical connection of towing and towed vehicles — 7-pole
connector type 24 S (supplementary) for vehicles with 24 V nominal supply voltage
ISO 7638--1, Road vehicles — Connectors for the electrical connection of towing and towed vehicles — Part 1:
Connectors for braking systems and running gear of vehicles with 24 V nominal supply voltage
ISO 12098, Road vehicles — Connectors for the electrical connection of towing and towed vehicles — 15-pole
connector for vehicles with 24 V nominal supply voltage
ISO 25981, Road vehicles — Connectors for the electrical connection of towing and towed vehicles — Connectors
for electronically monitored charging systems with 12 V or 24 V nominal supply voltage
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/
4 Connection locations
The locations for electrical and pneumatic connections shall be in accordance with Figure 1Figure 1 and
Figure 2Figure 2 for towing vehicles or trailers with rear--mounted couplings, Figure 3Figure 3 for towing
vehicles or trailers with couplings mounted forward and below, and Figure 4Figure 4 for articulated vehicles.
Selection of the respective locations shall be made such that the connectors are completely within the areas,
or zones, specified in the corresponding figure or figures. The connectors shall be mounted in the order
specified in Annex AAnnex A. Clearance dimensions shall be in accordance with Clause 6Clause 6.
Dimensions in millimetres
Within the shaded area, connections should be located as far outwards as possible. For ergonomic reasons, the connections should be
able to be operated while standing on one side only of the drawbar. As alternatives to mounting the connections left and right of
the vehicle’s longitudinal axis, they may be mounted only on the left side of the reference plane for left--hand drive vehicles, or
only on the righ
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