Troubleshooting › Electric power steering system › Diagnosis
U012987-故障诊断 · T00625086

 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 fault in the EPS communication module and communication with BCS_2 is lost.EPS通讯模块存在故障，与BCS_2失去通讯
1. Transmitter ECU failure1.发送器ECU故障
2.CAN bus failure2.CAN总线故障
3.EPS CAN module failure3.EPS CAN模块故障
Troubleshooting steps故障诊断步骤
①General 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 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。
3. Check the ACANFD communication harness connector for loose connections or damage.检查ACANFD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 Fault resolved.故障排除。
No否 Repair or replace faulty communication harness or connector.维修或更换故障通讯线束或接插件。
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 integrated brake control unit fault codes检查集成式制动控制单元故障码
1. Use a diagnostic tool to read the fault code of the integrated brake control unit and check whether there is a fault in the integrated brake control unit.使用诊断仪读取集成式制动控制单元故障码，检查集成式制动控制单元是否存在故障。
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 integrated brake control unit fault code according to the fault code.根据故障码排除集成式制动控制单元故障码。
⑤Replace the electric power steering column更换电动助力转向管柱
1. Replace the electric power steering column with a new one and check whether the fault code and symptoms are eliminated.更换新的电动助力转向管柱，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 electric power steering column, you need to use a diagnostic instrument to recalibrate the electric power steering column.更换电动助力转向管柱后，需用诊断仪对电动助力转向管柱重新标定。