中文
含义
室内外机通讯故障。室内机与室外机之间的通讯信号中断或数据错误，系统无法协调运行，通常内外机同时停止工作。
常见原因
- 室内外连接线中的通讯线（P/Q端子）断路或接触不良
- 室内外连接线极性接反（P/Q或S线错接）
- 通讯线屏蔽层未接地，受到室外强电干扰导致数据帧错误
- 室外机通讯电路光耦或通讯IC损坏
- 室内外机距离过远或线径过细，信号衰减严重
自助排查
- 检查室内机和室外机接线端子上的P/Q/通讯线是否连接牢固
- 确认通讯线极性正确——P接P、Q接Q，不可交叉连接
- 使用万用表测量通讯线是否导通，排除断线可能
- 若线路正常但仍报通讯故障，需逐段排查室内主板和室外主板通讯电路
English
Meaning
Indoor/outdoor communication fault. The communication signal between the indoor and outdoor units is interrupted or corrupted, preventing coordinated operation. Both units typically stop working.
Common Causes
- Open circuit or poor contact on the communication wires (P/Q terminals) between indoor and outdoor units
- Reversed polarity on the communication wiring (P/Q or S wires crossed)
- Shield ground not connected on the communication cable, allowing power-line interference to corrupt data frames
- Damaged optocoupler or communication IC on the outdoor unit main board
- Long cable run or undersized wire gauge causing severe signal attenuation
Self-Check Steps
- Check that the P/Q communication wires are firmly connected at both indoor and outdoor terminal blocks
- Confirm correct polarity — P to P, Q to Q, never crossed
- Use a multimeter continuity test to verify the communication wires are not broken
- If wiring is correct but the fault persists, trace the communication circuit at both indoor and outdoor main boards