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Details of Self-Diagnostics
When the operation selector on the indoor unit is switched from the ON or TEST position to the OFF (Self-diagnostics)
position, the indicator lamps on the indoor unit will blink (or remain lit) for 5 seconds and then turn OFF for 2 seconds
(buzzer sounds once) to indicate the presence of a sensor failure or the activation of a protective function.
Self-diagnostics is completed when the buzzer sounds 3 beeps.
If there is no trouble, the lamps neither blink nor illuminate. Also note that the corresponding parts listed below may not be
present in some models.
NOTE : If the operation lamp continues to blink (orange) even when the indoor unit operation selector has been
switched to the OFF position, there might be a trouble with the external ROM (E14) in the indoor unit.
After inspection or repair is completed, be sure to set the operation selector to the DEMO position, turn the
power ON, and erase the diagnostics contents.
Indication on indoor unit
.... OFF
Timer
Operation
Code
Diagnostics item
Diagnostics contents
S01
Room temperature sensor failure
1
Sensor open circuit or short circuit
2
Contact failure at connector or open circuit at terminal crimping location (short-circuit
detection only for the humidity sensor)
3
Indoor/outdoor circuit board failure
1
Sensor open circuit or short circuit
2
Contact failure at connector or open circuit at terminal crimping location
3
Outdoor circuit board failure
1
External ROM data failure
2
Outdoor circuit board failure
1
Outdoor circuit board failure
2
Outdoor power supply voltage failure
1
4-way valve failure (heat pump model only)
2
Outdoor circuit board failure
1
Service valve not opened.
2
Shortage of refrigerant
1
Open phase
2
Outdoor circuit board failure
1
Miswiring
2
AC power failure
3
Blown fuse
4
Power relay failure
5
Indoor or outdoor circuit board failure
1
Electric expansion valve failure
2
Capillaries choked
3
Shartage of refrigerant
4
Continuous overload operation
5
Outdoor fan does not rotate
6
Outdoor circuit board failure
1
Miswiring
2
Blown fuse
3
Power relay failure
4
Open phase
5
Outdoor circuit board failure
6
Compressor failure
1
Instantaneous power outage
2
HIC or power transistor failure
3
Outdoor circuit board failure
1
Fan motor failure
2
Contact failure at connector
3
Outdoor circuit board failure
1
Indoor fan system failure
2
Shortage of refrigerant
3
Low-temperature operation
1
Fan motor failure
2
Contact failure at connector
3
Indoor circuit board failure
1
HIC or power Tr failure
2
Outdoor fan does not turn.
3
Instantaneous power outage
4
Service valve not opened.
5
Outdoor fan blocked.
6
Continuous overload operation
7
Compressor failure
8
Outdoor circuit board failure
Indoor heat exchanger sensor failure
Humidity sensor failure
• Compressor temperature sensor failure
• SH sensor failure
• Outdoor heat exchanger sensor failure
• Outdoor narrow tubing sensor failure
• Outdoor air temperature sensor failure
Indoor/outdoor communications failure
(serial communications)
Outdoor unit external ROM failure
Peak current cut-off
• HIC circuit failure
• Power Tr (transistor) circuit failure
• PAM circuit failure
• Active circuit failure
• Outdoor system communications failure
• Outdoor high-pressure SW
• OLR operation
• Outdoor power supply open phase
• Outdoor coil freezing
Compressor discharge overheat
prevention activated.
Indoor fan operating failure
No-refrigerant protection
DC compressor drive circuit failure
Outdoor fan operating failure
Freeze-prevention operation activated.
• 4-way valve switching failure
• Indoor zero-cross failure
Outdoor electrical current detection
failure
Outdoor circuit board failure
S02
S03
S04
S05
S06
S07
E01
E02
E03
E04
E05
E06
E07
E08
E09
E10
E11
E12
E13
.... Blinking
.... Illuminated
