ISO 11446

Updated: 08/12/2025
By: Lars Nuwenhof

ISO 11446 – The standard for the 13-PIN connector for trucks and trailers

ISO 11446 is the international standard for the 13-PIN connector used on 12 trailers, caravans and trailers. This modern standard is widely used in Europe for vehicles with extensive electrical functions.

Structure of the standard

The original version ISO 11446:2004 has been replaced by a two-part structure:

ISO 11446-1:2012 - Functional requirements, dimensions and assignment
ISO 11446-2:2012 - For vehicles with increased sealing requirements

Applications of ISO 11446

The standard is suitable for vehicles with features such as:

Full lighting and signal transmission
Power supply of internal consumers such as refrigerator or battery
Semi-Trailer detection via CAN-bus

See also our step-by-step guide to trailer lighting or find out more about the regulations for trailer lighting.

Official pin assignment according to ISO 11446 - 13-PIN connector.

The overview below shows the standard PIN assignment according to ISO 11446, including colour coding.

PIN	Function	Type	Colour
1	Left-hand indicator	Signal	Yellow
2	Rear fog light	Lighting	Blue
3	Mass for PINs 1 to 8	Mass	White
4	Right-hand indicator	Signal	Green
5	Right rear lights	Lighting	Brown
6	Brake lights	Lighting	Red
7	Rear lights left	Lighting	Black
8	Reversing lights	Lighting	Grey
9	Permanent power supply (+12V)	Power supply	Orange
10	Switched power supply	Power supply	Dark grey
11	Mass for PIN 10	Mass	White/Black
12	Semi-Trailer detection or charging logic (CAN-bus)	Signal	Not standardised
13	Mass for PIN 9	Mass	White/Red

Use of PIN 12 in modern vehicles

PIN 12 was originally reserved and left unused for a long time. Since around 2018, it has been increasingly used for smart semi-trailer functions, such as:

Detection of a coupled trailer (parking sensors, ESP adjustment)
Charging logic for caravan batteries (fridge logic)
Power supply dependent on driving status or engine activity

These applications are now widely implemented in almost all car brands, provided the towbar module supports CAN-bus.

Also check out these related articles:

Reliable connectors and complete cable sets from TRALERT®

For trouble-free and durable installation of your ISO 11446 connectors, quality cabling is crucial. Check out our complete range of high-quality cable sets, junction boxes and connectors that meet the most stringent requirements in the transport sector.

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Author

Lars Nuwenhof

Lars is a lighting specialist at TRALERT® and responsible for the dealer portal. He writes about LED technology and helps customers with digital links and smart lighting solutions.

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Author

Lars Nuwenhof

Lars is a lighting specialist at TRALERT® and responsible for the dealer portal. He writes about LED technology and helps customers with digital links and smart lighting solutions.

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