IATF16949 On-board wiring harness

　　As the core standard for the automotive industry's quality management system, IATF 16949 imposes stringent requirements on wire harness manufacturers throughout their entire lifecycle. The following are key applications and practical points for wire harness production:

　　1. Deep Integration of the Standard's Core Requirements with Wire Harness Manufacturing

　　Process-Oriented and Risk-Based Thinking: IATF 16949 emphasizes defect prevention through process-based approaches (such as Advanced Product Quality Planning (APQP)) and risk assessment (such as Failure Mode Analysis (FMEA)). For example, wire harness manufacturers must identify potential risks such as poor crimping and shielding failure during the design phase and develop control measures through Design, Test, and Perform Factor Analysis (DFMEA). During production, SPC statistical process control must be implemented for key parameters (such as crimp height and pull-off force) to ensure process stability.

　　Dual Control of Design, Development, and Manufacturing Processes

　　Design Responsibility Boundaries: If a company undertakes wire harness design (such as connector layout and wire selection), it must fully adhere to ISO 9001 Section 8.3 (Product Design). If it only performs manufacturing, it may exclude product design but retain manufacturing process design (such as tooling and fixture design). Change Management: Design changes (such as material substitutions) must be managed through a closed-loop ECN (Engineering Change Notice) process to ensure suppliers simultaneously update process documentation and submit PPAP (Production Part Approval Process).

　　Full-Chain Compliance

　　Supplier Tier Management: Strict audits are conducted on suppliers of key raw materials, such as connectors and terminals, requiring them to obtain IATF 16949 certification and provide proof of compliance from sub-suppliers (such as RoHS test reports).

　　Special Characteristics Transfer: Safety-related characteristics (such as the withstand voltage rating of high-voltage wiring harnesses) are communicated to suppliers through technical agreements and required to be implemented throughout the downstream supply chain.

　　II. Key Technical Requirements and Implementation Paths for Wire Harness Manufacturing

　　Process Control and Error Prevention Mechanisms

　　High-voltage wiring harness control: Wire stripping and crimping must be performed using automated equipment, with 100% Hi-Pot testing performed and data stored until project completion. X-rays are used to detect conductor damage and ensure that crimp dimensions comply with USCAR standards. Error-proofing design: Key connection points utilize a four-step verification process (push-click-pull-push again). An automatic electrical testing system is also deployed to detect shorts and breaks. Rework areas utilize color management (red for defective components) to prevent confusion.

　　Material and Environmental Compatibility

　　Wire Selection: Based on the wiring harness's operating environment (e.g., high engine compartment temperatures and chassis vibration), select wire that is temperature-resistant (-40°C to 150°C), oil-resistant, and wear-resistant (e.g., German thin-walled wire or American irradiated wire). The wire must also meet ISO 6722 current-carrying capacity requirements.

　　Shielding Design: High-frequency signal lines (e.g., CAN FD) must utilize a double shield (aluminum foil + braided mesh) with a grounding spacing of ≤50mm to ensure EMC compliance with CISPR 25.

　　Testing and Traceability System

　　Full-Process Testing: From raw materials (e.g., copper wire conductivity testing) to finished products (e.g., vehicle-level vibration testing), multi-dimensional verification is performed using electrical performance test benches and durability testing equipment. Digital Traceability: The MES system enables electronic tracking of raw material batches, equipment parameters, and final inspection data, supporting forward and reverse traceability down to individual wiring harnesses.

　　III. Collaborative Implementation of Functional Safety and Regulatory Certification

　　Extended Application of ISO 26262 Functional Safety

　　Safety Mechanism Design: For safety-critical wiring harnesses (such as braking systems), redundant paths (such as dual-channel signal transmission) and fault detection mechanisms (such as contact resistance monitoring) must be designed to ensure a single-point fault metric (SPFM) of ≥90%.

　　ASIL Level Matching: Based on hazard analysis results, ASIL D wiring harnesses require hardware redundancy (such as dual controllers) and formal verification, while ASIL B can be achieved through basic testing.

　　Market Access Certification and Testing

　　Regional Certification: Exports to the EU require ECE certification (compliant with UN R10 EMC requirements), while domestic products require 3C certification (GB/T 30512 electrical safety testing). Industry Standards: Connectors must comply with standards such as USCAR-2 (mechanical properties) and USCAR-20 (sealing); high-voltage wiring harnesses must pass ISO 14572 (shielding effectiveness testing).

　　IV. Key Practical Points for Certification Implementation and Continuous Improvement

　　Changes in the Certification Process and the New Rules

　　Audit Cycle: Starting in 2025, the six-month and nine-month surveillance audit intervals will be eliminated, with a flexible -3/+3 month interval adopted. Serious non-conformities require corrective actions within 15 days, and special audit verification must be completed within 90 days.

　　Remote Audits: Some functions within support locations (such as design centers) can be audited remotely, but on-site verification at the manufacturing site is required.

　　Data-Driven Continuous Improvement

　　Intelligent Inspection Technology: Introducing machine vision (0.1mm accuracy) and deep learning algorithms to achieve a wire sequence recognition accuracy of ≥98%, reducing manual errors.

　　Quality Cost Optimization: Using SPC analysis to identify high-frequency defects (such as poor crimping) and combining it with FMEA to optimize control plans, one company has reduced customer claims by 42%. Differentiated Responses to Specific Customer Requirements

　　OEM Standards: For example, Toyota's QAV-1 requires increasing the frequency of wiring harness continuity testing to 100%, while Nissan's ANPQP mandates the use of a specific version of FMEA software. Companies must clearly define and embed this process into the Technical Agreement.

　　New Energy Trends: High-voltage wiring harnesses must meet ISO 6469-3 (Electric Vehicle Safety) and UL 2251 (On-Board Charging Systems) standards, developing specialized wiring harnesses that withstand high voltage (≥800V) and are corrosion-resistant.

　　V. Industry Benchmark Practices and the Value of Certification

　　Typical Case Studies

　　Sanneng Wiring Harness: After achieving IATF 16949 certification, the company introduced fully automatic wire crimping equipment and high-precision testing instruments, increasing production yield to 99.8%, successfully entering the supply chains of major domestic and international OEMs.

　　KSTAR: As the first company in the charging pile industry to achieve IATF 16949 certification, its charging wiring harnesses meet automotive-grade standards in terms of EMC and weather resistance, significantly enhancing its product competitiveness. Competitive Advantages of Certification

　　Market Access: IATF 16949 is a passport to high-end European and American markets. After one wire harness company obtained certification, its overseas order share increased from 15% to 40%.

　　Cost Control: Systematic process management (such as error-proofing and SPC) has helped companies reduce rework rates by over 30%, saving one company over 2 million yuan in annual quality costs.

　　VI. Future Trends and Challenges

　　Technology Convergence: With the increasing popularity of autonomous driving and 800V high-voltage platforms, wire harnesses will need to integrate more sensors (such as temperature and current monitoring) and adopt high-speed differential cables (such as HDMI 2.1) to meet high bandwidth requirements, placing higher demands on manufacturing precision and EMC performance.

　　Sustainability: IATF 16949 may incorporate more ESG (environmental, social, and governance) requirements in the future. Wire harness companies need to plan ahead in material selection (such as recyclable plastics) and process optimization (such as reducing energy consumption).