中文
含义
室内机与室外机通讯故障。室内机与室外机之间无法正常交换数据，空调完全无法运行或运行数分钟后停机报错。是分体空调最常见的故障之一。
常见原因
- 室内外机连接线松脱、接错或线径过细
- 通讯线路老化、破损或老鼠咬断
- 通讯电路光耦或双向二极管损坏
- 室外机开关电源24V/12V通讯驱动电压异常
- 室外机主控板受潮或脏污导致漏电拉低通讯电平
自助排查
- 检查室内外机接线端子是否松动、接反或氧化
- 使用万用表测量通讯线路两端直流电压，正常应有规律跳变的直流脉冲信号
- 观察室外机指示灯状态，判断室外机是否有供电
- 如线路完好，可能是通讯电路板损坏，需专业人员检修
English
Meaning
Indoor-outdoor communication failure. The indoor and outdoor units cannot exchange data properly, causing the air conditioner to not operate at all or to shut down with an error after a few minutes. This is one of the most common split-AC faults.
Common Causes
- Loose, mis-wired, or undersized interconnecting signal wires between indoor and outdoor units
- Aged, damaged, or rodent-chewed communication cable
- Failed optocoupler or bidirectional diode on the communication circuit
- Abnormal 24V/12V communication drive voltage from the outdoor unit switch-mode supply
- Outdoor control board contaminated by moisture or dirt, leaking communication signal level to ground
Self-Check Steps
- Inspect terminal blocks at both units for loose, reversed, or corroded connections
- Measure DC voltage across the communication wire pair — a normal circuit shows a fluctuating DC pulse signal
- Check the outdoor unit indicator LEDs to confirm it has power
- If wiring is intact, the communication circuit board is likely damaged — professional diagnosis required