U012987 - TroubleshootingU012987-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
U012987	There is a communication failure with BCS/IBCS and messages are lost.与BCS/IBCS通讯存在故障，报文丢失	1. Lost communication with BCS/IBCS1.与BCS/IBCS丢失通信

Troubleshooting steps故障诊断步骤

①General inspection一般检查

1. Check whether the ACANFD communication harness is damaged or broken.检查ACANFD通讯线束是否存在损坏、断裂等现象。 2. Check whether there is any loose connection or damage to the wiring harness connector.检查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 the faulty communication harness.维修或更换故障通讯线束。

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 BCS fault code检查BCS故障码

1. Use a diagnostic tool to read the BCS fault code and check whether there is a fault in the brake control system.使用诊断仪读取BCS故障码，检查制动控制系统是否存在故障。 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 Troubleshoot the brake control system according to the fault code.根据故障码排除制动控制系统故障。

⑤Replace lane departure warning ECU更换车道偏离预警ECU

1. Replace with a new lane departure warning ECU and check whether the fault code and symptoms are eliminated.更换新的车道偏离预警ECU，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 lane departure warning ECU, you need to use a diagnostic tool to recalibrate the lane departure warning ECU.更换车道偏离预警ECU后，需用诊断仪对车道偏离预警ECU重新标定。