Est. 1994
Current Version ISO 12098:2020
Scope 15-pin 24V trailer connectors
Regionality Worldwide

ISO 12098 is a standard for electrical trailer connectors used in the commercial vehicle industry. It has been developed as a replacement for the standards ISO 1185 and ISO 3731. The 15-pin system can transfer the same functionalities between towing vehicle and trailer as the prior system using only a single plug and socket connection. Additionally, it includes two data lines (CAN-H and CAN-L) according to ISO 11992-3 for the data interchange of equipment other than braking systems and running gear (which is covered by the ABS/EBS connector system according to ISO 7638-1).

The standard ISO 12098 specifies

  • the dimensional characteristics of 15-pin connectors for the electrical connection of equipment other than braking systems and running gear used in towing and towed vehicles with 24 V nominal supply voltage
  • the contact allocation as well as tests and requirements for the trailer connector system
  • a park socket for receiving and storing the plug when it is disconnected
  • a means of adaptation between 7- and 15-pin connectors
Semi-Trailer wiring
Application of trailer connectors according to ISO 12098

Contact Allocation for Connectors According to ISO 12098

Trailer socket according to ISO 12098
Trailer socket according to ISO 12098 with contact allocation in the cover
Contact allocation ISO 12098
Contact allocation of the 15-pin socket according to ISO 12098 with color coding (rear view)
Contact allocation ISO 12098 - plug
Contact allocation of the 15-pin plug according to ISO 12098 with color coding
 Contact no.FunctionCross-sectional areaCore insulation color
1Left-hand direction indicator light1,5 mm²yellow
2Right-hand direction indicator light1,5 mm²green
3Rear fog light1,5 mm²blue
4Common return2,5 mm²white
5Left-hand rear, position, and marker lights, and license plate lamp1,5 mm²black
6Right-hand rear, position, and marker lights, and license plate lamp1,5 mm²brown
7Brake lights1,5 mm²red
8Reversing light1,5 mm²pink
9Continuous power supply (steady, constant)2,5 mm²orange
10Reverse lock release for inertia brake and locking of steering axle1,5 mm²grey
11Starting-traction control system1,5 mm²white/black
12Axle lifting device1,5 mm²white/blue
13Common return for data lines2,5 mm²white/red
14CAN-H1,5 mm²white/green
15CAN-L1,5 mm²white/brown