35
DIAGNOSIS AND SOLUTION (CONT)
Open circuit or short circuit of temperature sensor diagnosis and solution (E4/E5/F1/F2/F3)
Error Code E4/E5/F1/F2/F3
Malfunction decision conditions If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays the failure.
Supposed causes
·Wiring mistake
·Sensor faulty
·PCB faulty
Troubleshooting
Check the connection 
between the temperature 
sensor and PCB.
Correct the connectionNo
Yes
Replace indoor or outdoor 
main PCB
Measure the resistance 
value of the sensor
Replace the sensorNo
Yes
Fig. 33 – Check the connection