U044781 - TroubleshootingU044781-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
U044781	The GWM node signal is invalid (0x35A, 0x083, 0x375, 0x3AC, 0x3AB, 0x208)GWM节点信号无效(0x35A、0x083、0x375、0x3AC、0x3AB、0x208)	1.CAN hardware failure, including CAN-H and CAN-L1.CAN硬件故障，包括CAN-H和CAN-L
		2. The bus line is disconnected2.总线线路断线
		3. The bus is disturbed3.总线受到干扰
		4. Controller abnormality4.控制器异常
		5.GWM node failure5.GWM节点故障
		6.GWM network is unstable6.GWM网络不稳定
		7. Other reasons: such as whether there is condensation inside the controller, condensation or evaporation of water droplets, grounding interference, etc.7.其它原因：如控制器内部是否有凝露，水滴凝结或者蒸发、接地干扰等等

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 the presence of magnetic fields.检查周围环境是否存在磁场。 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。

③General inspection一般检查

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 CAN communication harness is damaged or broken.检查CAN通讯线束是否存在损坏、断裂等现象。 3. Check the CAN communication harness connector for loose connections or damage.检查CAN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 CAN communication waveform检查CAN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 CAN-H and CAN-L.用示波器测量CAN-H和CAN-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 CAN communication harness; if normal, go to step 5.检查CAN通讯线束；若正常，去步骤5。

⑤Check the gateway controller检查网关控制器

1. Use a diagnostic tool to read the fault code of the gateway controller and check whether there is a fault in the gateway controller.使用诊断仪读取网关控制器故障码，检查网关控制器是否存在故障。 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 Troubleshoot according to the fault code.根据故障码排除故障。

⑥Replace electronic parking control unit更换电子驻车控制单元

1. Replace the electronic parking control unit with a new one and check whether the fault code and symptoms are eliminated.更换新的电子驻车控制单元，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 electronic parking control unit, you need to use a diagnostic tool to recalibrate the electronic parking control unit.更换电子驻车控制单元后，需用诊断仪对电子驻车控制单元重新标定。