00System
No malfunction detected (normal status)
Typical causes
- No malfunction detected in self-diagnosis mode
- Temporary status after a diagnostic check or reset
- Issue may be intermittent if cooling complaint still exists
Daikin Aircon Error Codes
Reference table for common Daikin codes. Use it to understand likely meaning, typical causes, and context before booking.
Before you use this tool
This is a guidance table, not a model-exact diagnosis. The same code can differ by series, controller, and model year. Use this page to narrow next steps, then verify with model sticker details.
Safety warning
Stop using the unit and contact a technician if the breaker trips repeatedly, you smell burning, see sparks, hear loud electrical buzzing, or water is leaking from places it normally should not.
Daikin code table
Includes common SG residential split-system codes with likely meaning and typical causes.
11Indoor
Indoor unit PCB or control abnormality
Typical causes
- System control logic detected abnormal operation
- Wiring/communication mismatch
- Controller or PCB fault
12System
Indoor and outdoor unit mismatch
Typical causes
- System control logic detected abnormal operation
- Wiring/communication mismatch
- Controller or PCB fault
13Communication
Indoor unit transmission error
Typical causes
- Loose or reversed interconnection wiring
- Poor terminal contact/corrosion
- Indoor/outdoor PCB communication circuit fault
- Power instability
14Sensor
Indoor refrigerant temperature sensor abnormal
Typical causes
- Temperature sensor open/short
- Sensor connector loose
- Sensor circuit fault on indoor PCB
15Sensor
Indoor air temperature sensor abnormal
Typical causes
- Temperature sensor open/short
- Sensor connector loose
- Sensor circuit fault on indoor PCB
89System
Abnormal water level in thermal storage unit
Typical causes
- Abnormal water level signal from storage tank
- Level sensor fault or wiring issue
- Control board interpretation error
97Outdoor
Radiation/auxiliary fan system malfunction
Typical causes
- Radiation fan or auxiliary fan circuit fault
- Fan motor/driver PCB problem
- Communication issue in fan control chain
A1Indoor
Indoor PCB fault
Typical causes
- Indoor PCB/component failure
- Loose or oxidised internal connectors
- Moisture or surge damage on control board
A3Indoor
Drain water level fault / drainage problem
Typical causes
- Blocked drain pipe or trap
- Faulty or stuck drain pump/float switch
- Heavy dirt buildup in drain pan
A5Indoor
Indoor heat exchanger overheat/freeze protection triggered
Typical causes
- Dirty indoor coil or filter reducing airflow
- Low refrigerant charge from leak
- Indoor thermistor reading out of range
A6Indoor
Indoor fan motor lock or overload
Typical causes
- Fan motor lock or winding fault
- Motor connector loose or damaged
- Indoor PCB drive circuit fault
A7Indoor
Swing flap motor fault
Typical causes
- Swing flap motor jammed or faulty
- Disconnected swing motor harness
- Indoor PCB output fault
A8Indoor
Indoor overcurrent or abnormal AC input
Typical causes
- Abnormal indoor input current or power surge
- Wiring short or poor terminal contact
- Indoor power circuit/PCB fault
A9Indoor
Electronic expansion valve (EEV) fault
Typical causes
- Electronic expansion valve stuck or coil faulty
- Valve harness disconnection
- Control PCB drive fault
AJSystem
Capacity setting or addressing error
Typical causes
- Incorrect indoor/outdoor capacity setting
- DIP switch or field setting mismatch
- Control PCB setting error
C3Sensor
Drain water level sensor abnormal
Typical causes
- Thermistor/sensor open or short circuit
- Loose or disconnected sensor connector
- Sensor harness damage or PCB input fault
C4Sensor
Indoor heat exchanger thermistor abnormal
Typical causes
- Thermistor/sensor open or short circuit
- Loose or disconnected sensor connector
- Sensor harness damage or PCB input fault
C5Sensor
Liquid pipe thermistor abnormal
Typical causes
- Thermistor/sensor open or short circuit
- Loose or disconnected sensor connector
- Sensor harness damage or PCB input fault
C6Sensor
Indoor fan motor thermistor abnormal
Typical causes
- Thermistor/sensor open or short circuit
- Loose or disconnected sensor connector
- Sensor harness damage or PCB input fault
C9Sensor
Indoor suction air thermistor abnormal
Typical causes
- Thermistor/sensor open or short circuit
- Loose or disconnected sensor connector
- Sensor harness damage or PCB input fault
CESensor
Radiation thermistor resistance abnormal
Typical causes
- Thermistor/sensor open or short circuit
- Loose or disconnected sensor connector
- Sensor harness damage or PCB input fault
CJSensor
Remote controller thermistor abnormal
Typical causes
- Thermistor/sensor open or short circuit
- Loose or disconnected sensor connector
- Sensor harness damage or PCB input fault
E0Outdoor
Outdoor protection device activated
Typical causes
- Outdoor protection device triggered
- Compressor or fan motor electrical fault
- Refrigerant circuit abnormality
E3Outdoor
High pressure protection activated
Typical causes
- Dirty condenser or blocked outdoor airflow
- Outdoor fan problem
- Refrigerant overcharge or non-condensables
E4Outdoor
Low pressure protection activated
Typical causes
- Low refrigerant due to leak
- Expansion device or piping restriction
- Insufficient heat load or sensor/control fault
E5Outdoor
Compressor overload / overcurrent protection
Typical causes
- Compressor overcurrent or thermal overload
- Voltage instability or wiring fault
- Refrigerant restriction causing high load
E6Outdoor
Compressor lock or startup failure
Typical causes
- Compressor lock/start failure
- Inverter drive fault
- Mechanical compressor fault
E7Outdoor
Outdoor fan motor lock fault
Typical causes
- Outdoor fan motor lock
- Fan motor connector/drive fault
- Outdoor PCB failure
E8Outdoor
Outdoor overcurrent protection
Typical causes
- Outdoor unit current spike
- Compressor winding or power module issue
- Power supply instability
F0Outdoor
Low refrigerant or suction temperature abnormal
Typical causes
- Low refrigerant due to leak
- Expansion device or piping restriction
- Insufficient heat load or sensor/control fault
F3Outdoor
Outdoor discharge pipe temperature too high
Typical causes
- Restricted refrigerant flow or low charge
- Discharge thermistor abnormal
- Compressor running under high load
F6Outdoor
Outdoor heat exchanger temperature high
Typical causes
- Restricted refrigerant flow or low charge
- Discharge thermistor abnormal
- Compressor running under high load
H3Outdoor
High pressure switch fault
Typical causes
- Dirty condenser or blocked outdoor airflow
- Outdoor fan problem
- Refrigerant overcharge or non-condensables
H4Outdoor
Low pressure switch fault
Typical causes
- Low refrigerant due to leak
- Expansion device or piping restriction
- Insufficient heat load or sensor/control fault
H6Sensor
Compressor position sensor fault
Typical causes
- Thermistor/sensor open or short circuit
- Loose or disconnected sensor connector
- Sensor harness damage or PCB input fault
H9Sensor
Outdoor air temperature thermistor fault
Typical causes
- Thermistor/sensor open or short circuit
- Loose or disconnected sensor connector
- Sensor harness damage or PCB input fault
J0Sensor
Refrigerant pressure sensor fault
Typical causes
- Pressure sensor faulty or out of calibration
- Sensor wiring issue
- Outdoor PCB input fault
J3Sensor
Discharge pipe thermistor fault
Typical causes
- Pipe thermistor fault or displacement
- Refrigerant circuit anomaly
- Sensor harness/PCB input fault
J5Sensor
Suction pipe thermistor fault
Typical causes
- Pipe thermistor fault or displacement
- Refrigerant circuit anomaly
- Sensor harness/PCB input fault
J6Sensor
Outdoor heat exchanger thermistor fault
Typical causes
- Pipe thermistor fault or displacement
- Refrigerant circuit anomaly
- Sensor harness/PCB input fault
JASensor
Discharge pressure sensor fault
Typical causes
- Pressure sensor faulty or out of calibration
- Sensor wiring issue
- Outdoor PCB input fault
JCSensor
Suction pressure sensor fault
Typical causes
- Pressure sensor faulty or out of calibration
- Sensor wiring issue
- Outdoor PCB input fault
L0Inverter
Inverter system fault
Typical causes
- Inverter IPM/power transistor fault
- Compressor electrical abnormality
- Heatsink overheating or weak airflow
- Supply voltage fluctuation
L3Inverter
Electrical parts overheating in inverter section
Typical causes
- Inverter IPM/power transistor fault
- Compressor electrical abnormality
- Heatsink overheating or weak airflow
- Supply voltage fluctuation
L4Inverter
Inverter heatsink temperature too high
Typical causes
- Inverter IPM/power transistor fault
- Compressor electrical abnormality
- Heatsink overheating or weak airflow
- Supply voltage fluctuation
L5Inverter
Inverter overcurrent / compressor lock protection
Typical causes
- Inverter IPM/power transistor fault
- Compressor electrical abnormality
- Heatsink overheating or weak airflow
- Supply voltage fluctuation
LAInverter
Power transistor (IPM) fault
Typical causes
- Inverter IPM/power transistor fault
- Compressor electrical abnormality
- Heatsink overheating or weak airflow
- Supply voltage fluctuation
P1System
Phase loss or voltage imbalance (3-phase)
Typical causes
- Phase loss or reverse phase on supply
- Voltage imbalance
- Main power wiring fault
P4Sensor
Inverter heatsink thermistor abnormal
Typical causes
- Thermistor/sensor open or short circuit
- Loose or disconnected sensor connector
- Sensor harness damage or PCB input fault
P5Sensor
DC current sensor abnormal
Typical causes
- Thermistor/sensor open or short circuit
- Loose or disconnected sensor connector
- Sensor harness damage or PCB input fault
P6Inverter
Inverter main circuit DC voltage abnormal
Typical causes
- Inverter IPM/power transistor fault
- Compressor electrical abnormality
- Heatsink overheating or weak airflow
- Supply voltage fluctuation
P8Outdoor
AC input overcurrent
Typical causes
- Outdoor unit current spike
- Compressor winding or power module issue
- Power supply instability
PJSystem
Field setting / capacity setting fault
Typical causes
- Incorrect indoor/outdoor capacity setting
- DIP switch or field setting mismatch
- Control PCB setting error
U0System
Refrigerant shortage or suction temperature abnormal
Typical causes
- Low refrigerant due to leak
- Expansion device or piping restriction
- Insufficient heat load or sensor/control fault
U1System
Reverse phase power supply
Typical causes
- Phase loss or reverse phase on supply
- Voltage imbalance
- Main power wiring fault
U2System
Power supply fault (voltage drop/open phase)
Typical causes
- Phase loss or reverse phase on supply
- Voltage imbalance
- Main power wiring fault
U3System
Check operation not completed / test run setting error
Typical causes
- Indoor/outdoor model combination mismatch
- Addressing or field setting error
- PCB setup/configuration fault
U4Communication
Communication error between indoor and outdoor units
Typical causes
- Loose or reversed interconnection wiring
- Poor terminal contact/corrosion
- Indoor/outdoor PCB communication circuit fault
- Power instability
U5Communication
Communication error between indoor unit and remote controller
Typical causes
- Remote-controller cable loose/damaged
- Remote controller board fault
- Indoor PCB communication fault
U7Communication
Communication error between outdoor units
Typical causes
- Loose or reversed interconnection wiring
- Poor terminal contact/corrosion
- Indoor/outdoor PCB communication circuit fault
- Power instability
UASystem
Indoor/outdoor combination or setting mismatch
Typical causes
- Indoor/outdoor model combination mismatch
- Addressing or field setting error
- PCB setup/configuration fault
UHSystem
System addressing/initialisation communication fault
Typical causes
- Indoor/outdoor model combination mismatch
- Addressing or field setting error
- PCB setup/configuration fault
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