在国六排放法规对OBD的要求和OBD诊断原理基础上，分析了OBD系统构成与功能模块。针对国六排放标准下OBD对DPF系统的关键功能性诊断，基于AVL BOOST仿真模拟了DPF堵塞、破损和被移除故障下的故障特征与敏感程度，并据此提出了相应的诊断策略。结果表明：DPF前、后温度的相关性和压降对各故障表现出了较好的敏感程度，可以作为OBD诊断策略区分压差传感器合理性故障与DPF破损、堵塞、移除的依据。

Based on the OBD requirements of China Ⅵ emission regulation and OBD diagnostic principles, the components and functional modules for OBD system were analyzed. Then the fault characteristics and sensitivity of DPF under the faults of channel plugging, carrier damaging and fault solving were simulated based on AVL Boost simulation software and the corresponding diagnosis strategies were proposed according to the key functional diagnosis of OBD for DPF system under China Ⅵ emission standard. The results show that the temperature correlation before and after DPF and the pressure drop show a good sensitivity to each fault and can be used as an OBD diagnosis strategy to distinguish between the reasonable faults of differential pressure sensor and the abovementioned faults.