2019款比亚迪秦EV无法上高压故障的诊断与排除

The 2019 BYD Qin EV Cannot Diagnose and Eliminate High-voltage Faults

文章围绕2019款比亚迪秦EV实训车辆的无法上高压故障展开,对故障现象、诊断过程及排除方法进行详细阐述。该故障表现为OK灯不亮、仪表显示“EV功能受限”以及无法挂挡行驶。经常规诊断与数据流分析,确定主接触器回路检测故障为直接原因,进一步检测发现BMS内部芯片烧毁,更换2个MOSFET后故障排除。最后总结出维修同类车型启动系统的注意事项,为同类故障维修提供一些参考。

This article focuses on the failure of 2019 BYD Qin EV practical training vehicle,and elaborates on the fault phenomenon,diagnosis process and elimination method.The fault is manifested as the OK light is not on,the instrument shows"EV function is limited",and the failure to drive in gear.After routine diagnosis and data flow analysis,it was determined that the main contactor loop detection fault was the direct cause,and further detection found that the chip inside the BMS burned down,and the fault was removed after replacing two MOSFETs.Finally,the points for attention in the maintenance of the starting system of similar models are summarized,and some references are provided for the maintenance of similar faults.