中文
含义
长虹空调检测到室内机与室外机之间通信故障，显示屏显示 E9 错误代码。E9 表示内外机之间的信号通信回路中断或出现数据错误。分体式空调的室内机和室外机通过通信线交换控制指令和状态信息，一旦通信失败，空调将无法正常启动运行，表现为室内机正常但室外机无响应。
常见原因
- 室内外机之间的通信连接线断线、接触不良、接反或绝缘层破损导致信号短路。
- 通信线接线端子氧化或受潮，导致信号传输阻抗增大通信不稳定。
- 室外机主板通信电路元件损坏（如光耦隔离器失效、通信芯片损坏）。
- 室内机主板通信电路故障，无法发出有效的通信信号。
- 室外机电源未送入（空开未合、电源线断开），室外机主板完全无电导致无法响应通信请求。
- 强电磁干扰（如附近有大功率电机、变频器等）耦合到通信线上，导致通信数据错误。
自助排查
- 确认室外机是否通电：检查室外机对应的空气开关（断路器）是否跳闸，如有则尝试合闸。如合闸后再次跳闸，说明室外机存在短路故障。
- 断开空调全部电源，检查室内外机之间的连接线缆外观是否有破损、被动物啃咬或接头松动的情况（只做外观检查，勿触碰线路）。
- 等待 5 分钟后重新通电开机，观察故障是否消除。偶发性通信干扰可能在重新上电后自行恢复。
- 如果家中近期进行过装修或线路改造，检查是否可能误动了空调内外机连线。
- 通信故障的电气检测需使用万用表和示波器测量通信线上的电压波形和数据信号。请联系长虹空调售后服务，由专业技师排查通信线路、接线端子及室内外机主板，确定故障点并修复。
English
Meaning
The Changhong air conditioner has detected an indoor-outdoor communication failure, displaying the E9 error code. E9 indicates the signal communication circuit between the indoor and outdoor units is interrupted or experiencing data errors. The indoor and outdoor units of a split-type air conditioner exchange control commands and status information via a communication line. Once communication fails, the AC cannot start and operate normally — the indoor unit appears normal but the outdoor unit does not respond.
Common Causes
- The communication wire between the indoor and outdoor units is broken, has poor contact, is reversed, or has damaged insulation causing signal short circuits.
- Communication wire terminals are oxidized or damp, causing increased signal transmission impedance and unstable communication.
- Communication circuit components on the outdoor unit main board are damaged (e.g., failed optocoupler isolator, damaged communication chip).
- The communication circuit on the indoor unit main board is faulty and cannot send valid communication signals.
- The outdoor unit is not receiving power (circuit breaker is off, power wire is disconnected) — the outdoor unit main board is completely unpowered and cannot respond to communication requests.
- Strong electromagnetic interference (e.g., nearby high-power motors, inverters) is coupling onto the communication line, causing communication data errors.
Self-Check Steps
- Confirm the outdoor unit is receiving power: check whether the outdoor unit’s circuit breaker has tripped. If so, attempt to reset it. If it trips again immediately, there is a short-circuit fault in the outdoor unit.
- Disconnect all AC power and visually inspect the connecting cable between the indoor and outdoor units for signs of damage, animal chewing, or loose connections (visual inspection only — do not touch the wiring).
- Wait 5 minutes, then reconnect power and start the unit. Observe whether the fault clears — occasional communication interference may self-recover after a power reset.
- If your home has undergone recent renovation or wiring changes, check whether the AC interconnecting wiring may have been disturbed.
- Electrical diagnostics for communication faults require a multimeter and oscilloscope to measure voltage waveforms and data signals on the communication line. Contact Changhong AC after-sales service for a professional technician to investigate the communication wiring, terminals, and indoor/outdoor unit main boards, locate the fault, and repair it.