中文
含义
E4表示空调室外机盘管温度传感器（室外管温NTC）出现故障。该传感器安装在室外机换热器上，用于检测室外盘管温度，在制冷时防止高压过高、制热时防止低压过低。
常见原因
- 传感器引线在室外长期日晒雨淋后老化断裂。
- 传感器插头腐蚀或进水导致接触不良。
- 传感器NTC元件因长期温度循环而性能劣化。
- 线束被室外动物咬断。
- 室外机主控板检测电路故障。
自助排查
- 关闭空调电源，等待10分钟后重新上电。
- 打开室外机侧板，找到安装在室外盘管上的管温传感器。
- 检查传感器线束是否有断裂、破损或插头松动。
- 用万用表测量传感器阻值（25℃时约5-15kΩ）。
- 若传感器损坏需更换，因室外作业难度较大，建议联系售后处理。
English
Meaning
E4 indicates an outdoor unit coil pipe temperature sensor (outdoor coil NTC) fault. This sensor is mounted on the outdoor heat exchanger to detect outdoor coil temperature — preventing high pressure during cooling and low pressure during heating.
Common Causes
- The sensor lead wire has aged and broken from prolonged sun and rain exposure outdoors.
- The sensor connector is corroded or moisture-damaged, causing poor contact.
- The NTC element has degraded from long-term temperature cycling.
- The wiring harness has been bitten by outdoor animals.
- The outdoor unit main control board detection circuit is faulty.
Self-Check Steps
- Turn off the A/C power, wait 10 minutes, then restart.
- Open the outdoor unit side panel and find the coil sensor on the outdoor coil.
- Check the sensor wiring for breaks, damage, or loose connectors.
- Use a multimeter to measure the sensor resistance (25°C: about 5-15kΩ).
- If the sensor is damaged, outdoor repair work is challenging — contact service.