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	T-CAN bus offlineT-CAN总线离线	1. Abnormal transceiver pins1.收发器管脚异常
		2. Other nodes on the bus send exceptions2.总线上其它节点发送异常

Troubleshooting steps故障诊断步骤

①Power on check上电检查

1. Repower the vehicle, use the diagnostic tool to read and clear the fault codes, and check whether the fault codes and symptoms are eliminated.车辆重新上电，使用诊断仪读取并清除故障码，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 your surroundings检查周围环境

1. Check the surrounding environment for sources of magnetic fields.检查周围环境是否存在磁场源。 Are the test results normal?检查结果是否正常？ Yes是 Go to step 3.去步骤3。 No否 Drive away from the current situation.驶离当前所处环境。

③Check wiring harness and connectors检查线束及接插件

1. Power state is "OFF", disconnect the negative terminal of the 12V battery.电源状态“OFF”，断开蓄电池负极。 2. Check whether the TCANFD communication harness is damaged or broken.检查TCANFD通讯线束是否存在损坏、断裂等现象。 3. Check the TCANFD communication harness connector for loose connections or damage.检查TCANFD通讯线束接插件是否存在虚接、损坏等现象。 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 Repair or replace faulty wiring harness or connector.维修或更换故障线束或接插件。

④Check TCANFD communication waveform检查TCANFD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 TCANFD-H and TCANFD-L.用示波器测量TCANFD-H和TCANFD-L的波形。 Are the test results normal?检查结果是否正常？ Yes是 Go to step 5.去步骤5。 No否 Check the TCANFD communication harness; if normal, go to step 5.检查TCANFD通讯线束；若正常，去步骤5。

⑤Check other related systems on the TCANFD communication bus检查TCANFD通讯总线上其他相关系统

1. Check whether other related systems on the TCANFD bus are normal.检查TCANFD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 6.去步骤6。 No否 Repair related faulty systems.维修相关故障系统。

⑥Replace T-BOX更换T-BOX

1. Replace with a new T-BOX and check whether the fault code and symptoms are eliminated.更换新的T-BOX，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 T-BOX, you need to use a diagnostic instrument to recalibrate the T-BOX.更换T-BOX后，需用诊断仪对T-BOX重新标定。