Abstract: An optimization study on electronic diagnosis is carried out to address the issue of the first activation failure of the fuel diagnosis module of tank leakage (DMTL) for vehicles with National VI emission standards during the vehicle's off-line electrical inspection. The research aims to address the diagnostic timeout anomalies caused by new software through software algorithm reconfiguration, while avoiding additional hardware modifications and production costs. By deeply analyzing the diagnostic logs, three innovative repair solutions are proposed: preloading for pre-order detection, dynamic switching of relays, and intelligent reset of the electronic control unit (ECU), and a multidimensional evaluation model is constructed. After verification by real vehicles, the ECU reset method achieves an 85% success rate for the first repair and a 100% success rate for the second repair while maintaining the integrity of the original diagnostic logic, and only increases the detection time by 30 s. This solution has been packaged into a standard software package and applied to the production line, reducing the per-vehicle repair time by 45%. The research results not only solve the mass production adaptation problem of the DMTL system, but also the software dynamic compensation strategy proposed by it provides a new method for the online diagnosis and optimization of automotive ECUs, which has significant engineering value for improving the reliability of the vehicle's emission system.

Key words: diagnosis module of tank leakage; electronic diagnostics; leakage diagnosis

摘要： 针对国六排放车型油箱泄露诊断模块（DMTL）在整车下线电检中首次激活失败的问 题，开展电子诊断优化研究。研究旨在通过软件算法重构，解决新软件导致的诊断超时异常， 同时避免增加硬件改动和生产成本。通过深度解析诊断日志，创新提出三种修复方案：前序 检测预加载、继电器动态切换和电子控制单元（ECU）智能复位，并构建多维度评估模型。 经实车验证，ECU 复位法在保持原有诊断逻辑完整性的前提下，首次修复成功率达 85%，二 次修复成功率为 100%，且仅增加 30 s 检测时间。该方案已封装为标准软件包应用于生产线， 使单车返修工时降低 45%。研究成果不仅解决了 DMTL 系统的量产适配难题，其提出的软件 动态补偿策略为汽车 ECU 的在线诊断优化提供了新方法，对提升整车排放系统可靠性具有重 要工程价值。

关键词: DMTL；电子诊断；泄露诊断