Boom Down (Single Function) Speed Is Slow
注: 开始任何故障排除步骤前，参考故障排除, "故障排除症状"。 使用 Cat® 电子技师（Cat ET）维修工具或机器监视器检查有无现行诊断代码。 如果存在诊断代码，请参阅相应的诊断代码故障排除步骤排除此故障然后再继续下一步。
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| 相关部件： | 可能原因： | 推荐行动： |
|---|---|---|
| 阀/管路 | 动臂沉降阻尼阀（DRV）提升阀故障 | 参考故障排除, "沉降阻尼阀 - 功能测试" |
| 惰轮旁通滑阀故障 | 参考故障排除, "旁通阀（ACS 阀）- 功能测试" | |
| 动臂泵至油缸连杆端（PCRE）滑阀故障 | 参考故障排除, "IMV 标定 - 功能测试" (1) 参考故障排除, "IMV 控制性能故障排除" (2) |
|
| 动臂泵至油缸缸盖端（PCHE）滑阀故障 | ||
| 动臂油缸至油箱缸盖端（CTHE）滑阀故障 | ||
| 先导压力低 | 参考测试和调整, KENR9615, "安全阀（先导）- 测试和调整" | |
| 先导安全阀故障 | 参考测试和调整, KENR9615, "安全阀（先导）- 测试和调整" | |
| 电子设备/线束/电磁阀 | 动臂/铲斗操纵手柄故障 | 参考故障排除, "操纵手柄 - 功能测试" (1) |
| 惰轮旁通比例液压调节阀（PHMV）故障 | 参考故障排除, "旁通阀（ACS 阀）- 功能测试" | |
| 动臂 PCRE PHMV 故障 | 参考故障排除, "IMV 标定 - 功能测试" (1) 参考故障排除, "IMV 控制性能故障排除" (2) |
|
| 动臂 PCHE PHMV 故障 | ||
| 动臂 CTHE PHMV 故障 | ||
| 动臂下降单向阀（BLCV）故障 | 请参阅相应的诊断代码故障排除步骤 | |
| ECM 故障。 ECM 不太可能有故障 | 更换 ECM 之前，务必向代理商的技术通信员征求 Caterpillar 可能的意见。 此咨询可能影响修理时间。 遵循故障诊断与排除, "ECM - 更换"中的步骤，以便更换 ECM | |
| 软件 | 动臂 PCRE PHMV 斜率电流不正确 | 参考故障排除, "IMV 标定 - 功能测试" |
| 动臂 PCHE PHMV 斜率电流不正确 | ||
| 动臂 CTHE PHMV 斜率电流不正确 | ||
| 动臂 PCRE PHMV 突破电流不正确 | ||
| 动臂 PCHE PHMV 突破电流不正确 | ||
| 动臂 CTHE PHMV 突破电流不正确 | ||
| 发动机 | 发动机转速低 | 参考故障排除, "液压功率 - 功能测试" |
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| ( 1 ) | 指示在故障排除顺序中应第一个完成的动作。 |
| ( 2 ) | 指示在故障排除过程中应作为最终选项考虑的功能测试。 |
Caterpillar Information System:
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