Service Manual
Table Of Contents
- SERVICE MANUAL
- 1. GENERAL INFORMATION
- 2. TECHNICAL DATA AND PARTS LIST
- 3. TROUBLESHOOTING
- 1. Error code
- 2. Troubleshooting with error code
- 2-1. E: 11. Serial communication error (Serial reverse transfer error) (Outdoor unit)
- 2-2. E: 11. Serial communication error (Serial forward transfer error) (Indoor unit)
- 2-3. E: 12. Wired remote controller communication error (Indoor unit)
- 2-4. E: 18. External communication error (Indoor unit)
- 2-5. E: 32. Indoor unit main PCB error (Indoor unit)
- 2-6. E: 35. MANUAL AUTO button error (Indoor unit)
- 2-7. E: 41. Room temperature sensor error (Indoor unit)
- 2-8. E: 42. Indoor unit heat exchanger sensor error (Indoor unit)
- 2-9. E: 51. Indoor unit fan motor error (Indoor unit)
- 2-10. E: 58. Intake grille error (Indoor unit)
- 2-11. E: 62. Outdoor unit main PCB error (Outdoor unit)
- 2-12. E: 63. Inverter error (Outdoor unit)
- 2-13. E: 64. PFC circuit error (Outdoor unit)
- 2-14. E: 71. Discharge thermistor error (Outdoor unit)
- 2-15. E: 73. Outdoor unit heat exchanger thermistor error (Outdoor unit)
- 2-16. E: 74. Outdoor temperature thermistor error (Outdoor unit)
- 2-17. E: 84. Current sensor error (Outdoor unit)
- 2-18. E: 94. Trip detection (Outdoor unit)
- 2-19. E: 95. Compressor motor control error (Outdoor unit)
- 2-20. E: 97. Outdoor unit fan motor error (Outdoor unit)
- 2-21. E: 99. 4-way valve error (Outdoor unit)
- 2-22. E: A1. Discharge temperature error (Outdoor unit)
- 3. Troubleshooting without error code
- 4. Troubleshooting with error code (For wireless LAN adapter)
- 4-1. E: 18. External communication error between indoor unit and WLAN adapter
- 4-2. Wireless LAN adapter error
- 4-3. Network communication error between wireless LAN router and WLAN adapter
- 4-4. E: 18. Communication error
- 4-5. E: 18. Wireless LAN adapter non-energized
- 4-6. Wireless LAN adapter Sleep mode (Indoor unit)
- 4-7. Mobile app setting method
- 5. Service parts information
- 6. Thermistor resistance values
- 4. CONTROL AND FUNCTIONS
- 1. Compressor frequency control
- 2. Auto changeover operation
- 3. Fan control
- 4. Louver control
- 5. Timer operation control
- 6. Defrost operation control
- 7. Various control
- 7-1. Auto restart
- 7-2. MANUAL AUTO operation
- 7-3. Forced cooling operation
- 7-4. 10 °C HEAT operation
- 7-5. ECONOMY operation
- 7-6. POWERFUL operation
- 7-7. Compressor preheating
- 7-8. Electronic expansion valve control
- 7-9. Prevention to restart for 3 minutes (3 minutes st)
- 7-10. 4-way valve control
- 7-11. Outdoor unit low noise operation
- 8. Various protections
- 5. FILED WORKING
2-16. E: 74. Outdoor temperature thermistor error (Outdoor unit)
Indicator Indoor unit
Operation indicator 7 time flash
Timer indicator 4 time flash
Economy indicator Continuous flash
Error code E: 74
Detective actuator
Outdoor unit main PCB When outdoor temperature thermistor open or short
circuit is detected at power on or while running the
compressor
Outdoor temperature thermistor
Forecast of cause
Connector failure
Thermistor failure
Main PCB failure
Check point 1. Check connection of connector
• Check if connector is loose or removed.
• Check erroneous connection.
• Check if thermistor cable is open
-> Reset power when reinstalling due to removed connector or incorrect wiring.
↓
Check point 2. Remove connector and check thermistor resistance value
• For the outdoor temperature thermistor resistance value, refer to "Thermistor re-
sistance values" on page 03-70.
• If thermistor is either open or shorted, replace it and reset the power.
↓
Check point 3. Check voltage of main PCB
Make sure circuit diagram of outdoor unit and check terminal voltage at thermistor
(DC 5.0 V).
NOTE: For details of thermistor connector, refer to "Wiring diagrams" in Chapter 2.
TECHNICAL DATA AND PARTS LIST on page 02-14.
If the voltage does not appear, replace main PCB.
↓
End
2-16. E: 74. Outdoor temperature thermistor error (Outdoor unit) - (03-26) - 2. Troubleshooting with error code
TROUBLESHOOTING
TROUBLESHOOTING