ISO 4141-4:2009

Overview

ISO 4141-4:2009 - Road vehicles - Multi-core connecting cables - Part 4: Test methods and requirements for coiled cable assemblies - specifies test methods and performance requirements for electrical coiled cable assemblies used to connect towing and towed road vehicles with nominal 12 V or 24 V systems. The standard defines preconditioning, endurance and mechanical strength tests, electrical monitoring criteria and voltage withstand requirements to ensure reliable connector and cable performance in trailer/towing applications.

Key Topics and Requirements

• Scope and applicability: Applies to coiled multi‑core connecting cables assembled with standard towing connectors for 12 V and 24 V vehicle systems.
• Preconditioning: Thermal preconditioning cycles at −40 °C and 80 °C followed by recovery at room temperature prior to testing.
• Articulation test: Simulates extreme bending angles between vehicle and trailer; includes rotation about a defined axis and requires at least 20 000 continuous cycles without cracking or anti‑kink displacement. Conductor continuity is monitored with a (5 ± 0.5) A current; failures are detected if current drops by >1.0 A for >10 ms.
• Torsion strain test: Verifies mechanical strength under cable rotation/torque. Requires a minimum of 1 mechanical cycle and 1 000 electrical cycles for electrical breakdown testing; rotation up to 360° with torque limits and monitoring as in the articulation test.
• Electrical withstand: If no conductor breakage occurs, apply a test voltage of 1 kV RMS (50/60 Hz) or 1 600 V DC for 1 minute between each conductor and the remaining conductors tied together; no breakdown allowed.
• Monitoring and test arrangements: Specifies connection diagrams for conductor breakage monitoring and voltage tests, and designation/marking rules for coiled cable assemblies (Annex A/B).

Applications and Users

Who uses ISO 4141-4:2009:

• OEMs and vehicle manufacturers specifying trailer/towing electrical interfaces.
• Cable and connector manufacturers designing and qualifying coiled cable assemblies.
• Test laboratories performing mechanical and electrical endurance tests.
• Fleet operators and component suppliers seeking compliance and robust towing connections. Practical benefits include improved reliability of trailer electrical connections, reduced field failures from bending and torsion, and harmonized supplier testing and acceptance criteria.

Related Standards

Relevant companion and referenced standards (normative):

• ISO 4141-3:2006 (construction, dimensions and marking of cables)
• Connector standards: ISO 1185, ISO 1724, ISO 3731, ISO 3732, ISO 7638-1, ISO 7638-2, ISO 11446, ISO 12098, ISO 25981 These define compatible plug/socket types and complement ISO 4141-4’s test methods and acceptance criteria.

Keywords: ISO 4141-4:2009, coiled cable assemblies, multi-core connecting cables, road vehicles, test methods, articulation test, torsion strain, 12 V, 24 V, withstand voltage.