B1C4D04 - TroubleshootingB1C4D04-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
B1C4D04	Front steam electronic expansion valve initialization failure前蒸电子膨胀阀初始化故障	1. Front steam electronic expansion valve LIN communication interference or wiring harness failure1.前蒸电子膨胀阀LIN通讯干扰或线束故障
		2. Initialization execution timing exception2.初始化执行时序异常

Troubleshooting steps故障诊断步骤

①General inspection一般检查

1. Power status is "OFF", disconnect the negative terminal of the 12V battery.电源状态“OFF”,断开蓄电池负极。 2. Check the evaporator electronic expansion valve wiring harness for damage, breakage, etc.检查蒸发器电子膨胀阀线束是否存在损坏、断裂等现象。 3. Check the evaporator electronic expansion valve wiring harness connector for loose connection or damage.检查蒸发器电子膨胀阀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 2.去步骤2。 No否 Repair or replace faulty wiring harness or connector.维修或更换故障线束或接插件。

②Power 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 3.去步骤3。

③Check LIN communication waveform检查LIN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. Measure the LIN waveform with an oscilloscope.用示波器测量LIN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 LIN communication harness; if normal, go to step 4.检查LIN通讯线束；若正常，去步骤4。

④Replace the evaporator electronic expansion valve更换蒸发器电子膨胀阀

1. Replace the evaporator electronic expansion valve with a new one, and check whether the fault code and symptoms are eliminated.更换新的蒸发器电子膨胀阀，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 5.去步骤5。

⑤Replacing the thermal management integrated module更换热管理集成模块

1. Replace the thermal management integrated module with a new one and check whether the fault code and symptoms are eliminated.更换新的热管理集成模块，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 thermal management integrated module, you need to use a diagnostic instrument to recalibrate the thermal management integrated module.更换热管理集成模块后，需用诊断仪对热管理集成模块重新标定。