15-pin ISO 12098 wiring diagram

15-PIN ISO 12098 connector wiring diagram (24V trucks & trailer)

This wiring diagram shows the pin configuration of a 15-PIN ISO 12098 connector (24V), as used in trucks and trailers. The scheme is used for lighting, auxiliary functions and return circuits within the vehicle and semi-trailer wiring.

In practice, the 15-PIN ISO 12098 replaces the 7-PIN N-connector (ISO 1185) and S-connector (ISO 3731). For wiring diagrams of these older connectors, please refer to our explanation of the 7-PIN N-connector to ISO 1185 and the 7-PIN S-connector to ISO 3731. Are you dealing with a 13-PIN connection? If so, please refer to our wiring diagram for the 13-PIN connector in accordance with ISO 11446.

1. Flashing light left
2. Flashing light right
3. Rear fog light
4. Mass
5. Rear, contour, width and licence plate lights left
6. Right rear, contour, width and licence plate lights
7. Brake lights
8. Reversing lights
9. Constant power supply (+24 V)
10. Sensor for brake lining wear
11. Spring-loaded brake indication
12. Aslift function
13. Mass for data cables
14. CAN H
15. CAN L

How does the ISO 12098 15-pin connector work?

The ISO 12098 connector provides a standard 24V connection for lighting and auxiliary functions between the truck and trailer. The connector replaces the 7-PIN N and S connectors with connector single connector, ensuring a clear connection for lighting in vehicle construction. It is currently the most widely used wiring diagram for trucks.

ISO 12098 connections on electric trucks

With the rise of electric trucks and heavy-duty electric vehicles (e-trucks), the 15-PIN connector in accordance with ISO 12098 remains the standard for reliable communication between vehicle and trailer.

Nevertheless, there are a few points of interest in practice:

• Not every electric tractor activates all pin functions automatically
• Power supply via PIN 15 (ignition switched) is not always available with EVs
• LED lighting in combination with a 24V CAN-bus system often requires specific adapters or resistor modules

What is the difference between 7-pin, 13-pin and 15-pin connectors?

Different plug types occur in vehicle construction, each with its own standard and application. The table below shows at a glance which connector is used for what.

The 15-PIN ISO 12098 connector has become the standard in modern vehicle construction, as it combines the functions of both N and S connectors in one connector. This simplifies cabling, reduces the number of connections and allows for additional signals such as CAN-bus and sensor information.

Frequently asked questions from the workshop

PIN 15 (contact switched) is not active on an electric tractor. What now?

In many electric tractors, the ignition switched power supply does not automatically run via PIN 15 as it does in diesel vehicles. Check the vehicle documentation first: some manufacturers put PIN 15 on an auxiliary relay or require a software configuration. In practice, LED lighting that depends on a stable +24V on PIN 15 often requires a switching module or CAN-controlled relay control.

Which PINs are involved in CAN-bus communication in ISO 12098?

Pin 14 (CAN H) and pin 15 (CAN L) handle CAN-bus communication. Mass for the data cabling runs via PIN 13 (white/red). Please note: in some older ISO 12098 implementations, PIN 15 is used solely for contact-switched power supply without CAN functionality. Always check the scheme for the specific tractor and semi-trailer.

My LED lighting gives error messages via CAN-bus. What is the cause?

LED lighting draws significantly less current than incandescent bulbs, which means the vehicle may detect a bulb failure. With 24V CAN-bus systems, you can resolve this using CAN-bus solutions or resistor modules that simulate power consumption. When used in conjunction with ISO 12098, you should also check that the adapter transmits all relevant pin functions. See also our article on canbus interference.

What is the difference in pin assignment between ISO 12098 and the old N+S combination?

The ISO 12098 combines the functions of ISO 1185 (N-plug, basic lighting) and ISO 3731 (S-plug, additional functions) in one connector. PIN 1 to 8 broadly cover the N-plug functions, PIN 9 to 13 the S-functions, and PIN 14 and 15 are added for CAN-bus communication. When converting, a 1-to-1 adapter is not possible: use a specifically designed adapter or replace the entire wiring.

Related articles

• 7-PIN connector (24V, ISO 1185).
• 7-PIN connector (24V, ISO 3731).
• 13-PIN connector (ISO 11446).
• CAN-bus solutions for LED lighting
• Lighting for agricultural vehicles
• Lighting for agricultural implements
• 24 v lighting for semi-trailer construction