U007388 - TroubleshootingU007388-故障诊断

Fault code description故障码说明

DTC故障码(DTC)	Fault code description故障码描述	Possible cause of failure可能故障原因
U007388	Vehicle CAN BusOff整车CAN BusOff	1. Poor bus communication quality1.总线通讯质量差
		2.Can signal interference2.Can信号干扰
		3. CAN line open circuit or short circuit3.CAN线路开路、短路

Troubleshooting steps故障诊断步骤

①Power on check上电检查

1. Power on the vehicle again and check whether the fault code and symptoms are eliminated.车辆重新上电，检查故障码及症状是否排除。 Are the test results normal?检查结果是否正常？ Yes是 Fault resolved.故障排除。 No否 Go to step 2.去步骤2。

②Check ECAN communication waveform检查ECAN通讯波形

1. Power status "OFF".电源状态“OFF”。 2. Connect the oscilloscope.连接示波器。 3. Power status "ON".电源状态“ON”。 4. Use an oscilloscope to measure the waveforms of ECAN-H and ECAN-L.用示波器测量ECAN-H和ECAN-L的波形。 Are the test results normal?检查结果是否正常？ Yes是 Go to step 4.去步骤4。 No否 Check the ECAN communication harness; if normal, go to step 3.检查ECAN通讯线束；若正常，去步骤3。

③Check other related systems on the ECAN communication bus检查ECAN通讯总线上其他相关系统

1. Check whether other related systems on the ECAN bus are normal.检查ECAN总线上其他相关系统是否正常。 Are the test results normal?检查结果是否正常？ Yes是 Go to step 4.去步骤4。 No否 Troubleshoot related faulty systems.检修相关故障系统。

④Replacing the integrated electric drive assembly更换集成电力驱动总成

1. Replace the integrated electric drive assembly with a new one and check whether the fault code and symptoms are eliminated.更换新的集成电力驱动总成，检查故障码及症状是否排除。 Are the test results normal?检查结果是否正常？ Yes是 Fault resolved.故障排除。 No否 Look for causes from other symptoms.从其他症状查找原因。   Caution:注意： ♦  After replacing the integrated electric drive assembly, you need to use a diagnostic tool to recalibrate the integrated electric drive assembly.更换集成电力驱动总成后，需用诊断仪对集成电力驱动总成重新标定。