U203781 - TroubleshootingU203781-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
U203781	AGS2 LIN response failureAGS2 LIN响应故障	1.AGS2 failure1.AGS2故障

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 whether the active air intake grille wiring harness is damaged or broken.检查下主动进气格栅线束是否存在损坏、断裂等现象。 3. Check the active air intake grille harness connector to see if there is any loose connection or damage.检查下主动进气格栅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 for electromagnetic interference检查电磁干扰

1. Check for sources of magnetic fields around the vehicle.检查车辆周围是否存在磁场源。 Are the test results normal?检查结果是否正常？ Yes是 Go to step 4.去步骤4。 No否 Move the vehicle away from its current environment.使车辆驶离当前环境。

④Check 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 5.去步骤5。 No否 Check the LIN communication harness; if normal, go to step 5.检查LIN通讯线束；若正常，去步骤5。

⑤Replace active air intake grille更换下主动进气格栅

1. Replace the lower active air intake grille with a new one, and check whether the fault code and symptoms are eliminated.更换新的下主动进气格栅，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 6.去步骤6。

⑥Replacing 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。