C004900 - TroubleshootingC004900-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
C004900	Brake fluid sensor open/grounded制动液传感器开路/接地	1. The output value of the brake fluid level sensor is abnormal.1.刹车液液位传感器输出值异常

Troubleshooting steps故障诊断步骤

①Power on check上电检查
1. Power on the vehicle again and check whether the fault code and symptoms are eliminated.车辆重新上电，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 the brake fluid level switch wiring harness for damage, breakage, etc.检查制动液位开关线束是否存在损坏、断裂等现象。 3. Check the brake fluid level switch harness connector for damage, loose connection, etc.检查制动液位开关线束接插件是否存在损坏、虚接等现象。 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 brake fluid level switch signal circuit检查制动液位开关信号线路
	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 integrated brake control unit harness connector FB47 and brake fluid level switch harness connector FB49.断开集成式制动控制单元线束接插件FB47和制动液位开关线束接插件FB49。 3. Use a digital multimeter to measure the resistance between pin 39 of FB47 and pin 2 of FB49.使用数字万用表测量FB47的39号针脚与FB49的2号针脚之间的电阻。 Standard resistance value: <1标准电阻值：＜1 Ω
	d. Use a digital multimeter to measure the resistance between pin 39 of FB47 and ground.d.使用数字万用表测量FB47的39号针脚与接地之间的电阻。 Standard resistance value: >1M标准电阻值：＞1M 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 faulty wiring harness or connector.维修或更换故障线束或接插件。
④Replacing the integrated brake control unit更换集成式制动控制单元
1. Replace with a new integrated brake control unit and check whether the fault code and symptoms are eliminated.更换新的集成式制动控制单元，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 brake control unit, you need to use a diagnostic tool to recalibrate the integrated brake control unit.更换集成式制动控制单元后，需用诊断仪对集成式制动控制单元重新标定。 ♦  After replacing the integrated brake control unit, the brake line bleeding operation is required.更换集成式制动控制单元后，需进行制动管路排气操作。