中文
含义
长虹空调检测到室外机冷凝器盘管温度传感器故障，显示屏显示 E4 错误代码。室外盘管传感器监测冷凝器表面温度，控制系统依靠此数据进行制冷剂冷凝状态判断、室外风机调速和化霜控制。传感器故障可能导致空调制冷效果变差、室外机频繁化霜或不化霜，以及冬季制热能力下降。
常见原因
- 室外盘管温度传感器（NTC 热敏电阻）老化、阻值漂移或开路/短路。
- 传感器与室外机主板的连接插头因风吹雨淋而腐蚀或松动。
- 室外机长期暴露在日晒雨淋、高低温循环环境中，传感器外壳老化开裂，内部进水导致失效。
- 传感器信号线被老鼠、鸟等小动物咬断，或线缆绝缘层破损导致信号短路到地。
- 室外机主板传感器检测电路故障。
- 冷凝器翅片严重积灰或异物堵塞，传感器实际接触位置温度不代表冷凝器整体状态。
自助排查
- 断开空调电源 3 分钟后再通电开机，观察 E4 代码是否消除。户外传感器因环境恶劣可能偶尔出现接触波动。
- 目视检查室外机冷凝器翅片是否被大量灰尘、柳絮或杂物堵塞，如有可用水管冲洗翅片表面（注意避开电器盒和接线端子）。
- 如果条件允许，检查室外机电器盒内的线缆连接是否有明显松动或腐蚀痕迹（需在断电后进行），但不要触碰电路板。
- 观察故障出现规律：如果 E4 仅在雨天或湿度较大时出现，传感器或连接器受潮的可能性较大。
- 室外盘管传感器故障需由专业技师使用万用表对比传感器实际阻值与标准阻温特性表的偏差。请联系长虹空调售后安排上门检修。
English
Meaning
The Changhong air conditioner has detected an outdoor condenser coil temperature sensor fault, displaying the E4 error code. The outdoor coil sensor monitors the condenser surface temperature. The control system relies on this data for refrigerant condensation status assessment, outdoor fan speed control, and defrost control. A sensor fault may cause reduced cooling performance, frequent or absent outdoor unit defrosting, and degraded heating capacity in winter.
Common Causes
- The outdoor coil temperature sensor (NTC thermistor) has aged, drifted in resistance, or has an open/short circuit.
- The sensor connector to the outdoor unit main board has corroded or loosened due to exposure to wind and rain.
- Prolonged exposure to sun, rain, and high/low temperature cycles has caused the sensor housing to age and crack, with water ingress causing internal failure.
- The sensor signal wire has been chewed through by rodents or birds, or the insulation has been damaged causing the signal to short to ground.
- The sensor detection circuit on the outdoor unit main board is faulty.
- The condenser fins are heavily clogged with dust or debris, and the temperature at the sensor’s actual contact point does not represent the overall condenser state.
Self-Check Steps
- Disconnect the AC from power for 3 minutes, then reconnect and start. Observe whether the E4 code clears — outdoor sensors in harsh environments may occasionally exhibit contact fluctuations.
- Visually inspect the outdoor unit’s condenser fins for heavy dust, catkin, or debris buildup. If found, rinse the fin surface with a water hose (taking care to avoid the electrical box and terminal connections).
- If accessible, check the cable connections inside the outdoor unit’s electrical box for visible looseness or corrosion (must be done with power disconnected) — but do not touch the circuit board.
- Observe the fault pattern: if E4 only appears during rainy or high-humidity conditions, moisture in the sensor or connector is likely the cause.
- Outdoor coil sensor faults require a professional technician to compare the sensor’s actual resistance with the standard resistance-temperature characteristic table using a multimeter. Contact Changhong AC after-sales service to arrange an on-site inspection.