U120A87 - TroubleshootingU120A87-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
U120A87	RPA/PAS packets are lostRPA/PAS报文丢失	1.PAS node is offline1.PAS节点离线
		2.PAS node is damaged2.PAS节点损坏
		3. The PAS node does not send messages according to the scheduled period.3.PAS节点未按预定周期发出报文

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。
②General 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 parking sensor controller is damaged or broken.检查倒车雷达控制器是否存在损坏、断裂等现象。 3. Check the wiring harness connector of the parking sensor controller for loose connection or damage.检查倒车雷达控制器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 3.去步骤3。 No否 Repair or replace faulty wiring harness or connector.维修或更换故障线束或接插件。
③Check the communication harness between the gateway controller and the parking sensor controller检查网关控制器与倒车雷达控制器之间的通讯线束
	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. Disconnect the gateway controller (Ethernet) harness connector IP60 and the parking sensor controller harness connector RB06.断开网关控制器(以太网)线束接插件IP60和倒车雷达控制器线束接插件RB06。 3. Use a digital multimeter to measure the resistance between pin 9/24 of IP60 and pin 1/8 of RB06.使用数字万用表测量IP60的9/24号针脚与RB06的1/8号针脚之间的电阻。 Standard resistance value: <1标准电阻值：＜1 Ω 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 the faulty wiring harness.维修或更换故障线束。
④Check the parking sensor controller检查倒车雷达控制器
1. Power status "OFF".电源状态“OFF”。 2. Connect the diagnostic tool.连接诊断仪。 3. Power status "ON".电源状态“ON”。 4. Use the diagnostic tool to check whether the parking sensor controller system is normal.使用诊断仪检查倒车雷达控制器系统是否正常。 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 Repair the parking sensor controller system.检修倒车雷达控制器系统。
⑤Replace gateway controller更换网关控制器
1. Replace with a new gateway controller and check whether the fault code and symptoms are eliminated.更换新的网关控制器，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 gateway controller, you need to use a diagnostic tool to recalibrate the gateway controller.更换网关控制器后，需用诊断仪对网关控制器重新标定。