P18A991 - TroubleshootingP18A991-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
P18A991	Motor overspeed Level1电机超速 Level1	1. The resolver sampling circuit is faulty or the target torque given by the VCU is wrong.1.旋变采样电路故障或VCU给定目标扭矩错误

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。

②Check vehicle control system检查整车控制系统

1. Check whether the vehicle control system is normal.检查整车控制系统是否正常。 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 Overhaul the vehicle control system.检修整车控制系统。

③Check brake control system检查制动控制系统

1. Check whether the brake control system is normal.检查制动控制系统是否正常。 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 Overhaul the brake control system.检修制动控制系统。

④Replacing the integrated electric drive assembly更换集成电力驱动总成

1. Replace the integrated electric drive assembly with a new one and check whether the fault code and symptoms are eliminated.更换新的集成电力驱动总成，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 integrated electric drive assembly, you need to use a diagnostic tool to recalibrate the integrated electric drive assembly.更换集成电力驱动总成后，需用诊断仪对集成电力驱动总成重新标定。