中文
含义
室外单元通信异常。室内机向室外机发送通讯帧后长时间未收到有效回应，或室外机发送的数据帧格式无法被室内机正确解析。
常见原因
- 室外机主板电源异常（如开关电源输出偏低），微控制器未正常启动
- 室外机通讯电路收发IC损坏
- 室外机CPU晶振失效或复位电路异常
- 室内外通讯线接触不良或线束中有断股
- 室外机遭遇雷击导致通讯接口电路损坏
自助排查
- 确认室外机是否有供电（听压缩机继电器是否有吸合声或指示灯）
- 使用万用表测量室内外通讯线的直流电压（正常通常在DC 15-30V间波动）
- 检查通讯线连接端子是否腐蚀或松动
- 若电压异常或无波动，分别测量室内机和室外机端子的通讯电压以定位故障侧
English
Meaning
Outdoor unit communication abnormal. The indoor unit has sent communication frames but received no valid response from the outdoor unit for an extended period, or the data frames sent by the outdoor unit cannot be properly parsed by the indoor unit.
Common Causes
- Outdoor main board power supply abnormal (e.g. low switching-mode output) — MCU not starting properly
- Damaged transceiver IC on the outdoor unit communication circuit
- Faulty crystal oscillator or abnormal reset circuit on the outdoor CPU
- Loose communication wire contact or broken strands in the wiring harness
- Lightning strike damaging the outdoor unit communication interface circuit
Self-Check Steps
- Confirm the outdoor unit is powered (listen for compressor relay click or indicator LED)
- Measure the DC voltage across the indoor-outdoor communication wires (typically fluctuating between DC 15-30V)
- Check communication wire terminals for corrosion or looseness
- If the voltage is abnormal or flat, measure the communication voltage at both indoor and outdoor terminals to locate the fault side