Sooner or later, any air conditioner, even the one of the best quality, can break down. Malfunctions can be both serious, requiring expensive repairs, and minor ones, which can be prevented in the majority of cases with timely maintenance. Let’s consider the main types of breakdowns and possible ways of their repair.

Fujitsu Air Conditioner wall mounted Type Inverter Faults Codes

Error	Indoor unit LED Operation LED	Indoor unit LED Timer LED	Wired remote control	Error
Serial signal error	Off	2flash	01	Serial signal (reverse) error, at operation start up
		3 flash	01	Serial signal (reverse) error, during oeration
		4 flash	13	Serial signal (forward) error, at operation start up
		5 flash	13	Serial signal (forward) error, during operation
		8 flash	00	Wired remote control error
Indoor unit thermistor error	2 flash	2 flash	02	Indoor air thermistor error
		3 flash	04	Heat exchanger middle thermistor error
Outdoor unit thermistor error	3 flash	2 flash	0C	Discharge pipe thermistor error
		3 flash	06	Heat exchanger thermistor error
		4 flash	0A	Outdoor air thermistor error
Indoor unit control error	4 flash	2 flash	20	Manual auto button welded
		3 flash	-	Main relay welded
		4 flash	2A	Not distinguishing 50 Hz or 60 Hz
Outdoor unit control error	5 flash	2 flash	17	Current trip error
		3 flash	18	CT abnormal
		5 flash	1A	Compressor location detection error
		6 flash	1B	Outdoor unit fan drive system abnormal
Indoor fan motor error	6 flash	2 flash	12	Abnormal lock (upper fan motor)
		3 flash	12	Abnormal rotation (upper fan motor)
Refrigerant cycle error	7 flash	2 flash	0F	Discharge temperature abnormal
		3 flash	24	Cooling high pressure abnormal rise
		4 flash	2C ?	DC 4-way valve and expansion valve abnormal
Optional function error	8 flash	2 flash	19	Active filter error (first)
		3 flash	19	Active filter error (second)
		4 flash	25	PFC circuit error
Model information error	0.1 sec on/off	0.1 sec on/off	11	Model information error

Fujitsu Air Conditioner Inverter Split Type Faults Codes

Fault Code	Error contents
01 13 26 27	Indoor signal error
00	Wired remote controller abnormal
02	Indoor room temperature sensor error
04	Indoor heat exchanger temperature sensor (middle) error
28	Indoor heat exchanger temperature sensor (inlet) error
09	Float switch operated
0C	Outdoor discharge pipe temperature sensor error
06	Outdoor heat exchanger temperature sensor (outlet) error
0A	Outdoor temperature sensor error
15	Compressor temperature sensor error
1d	2-way valve temperature sensor error
1E	3-way valve temperature sensor error
29	Outdoor heat exchanger temperature sensor (middle) error
20	Indoor manual auto switch abnormal
2A	Power supply frequency detection error
17	IPM protection
18	CT error
1A	Compressor location error
1b	Outdoor fan error
1F	Connected indoor unit abnormal
1c	Outdoor unit computer communication error
12	Indoor fan abnormal
0F	Discharge temperature error
24	Exessive high pressure protection on cooling
2c	4-way valve abnormal
16	Pressure switch abnormal
2b	Compressor temperature error
19	Active filter abnormal
25	PFC circuit error
CO	Remote control error. Refer to the installation instruction sheet included with the remote control

Outdoor unit

LED	ERROR CONTENTS
FLASH (0.1sec ON/0.1sec OFF)	Temperature sensor error
FLASH (0.5sec ON/0.5sec OFF)	IPM protection
FLASH (2sec ON/2sec OFF)	Current trans. error
FLASH (5sec ON/5sec OFF)	Outdoor fan error
FLASH (0.1sec ON/2sec OFF)	Compressor rotor position cannot be detected
FLASH (5sec ON/0.1sec OFF)	ACTPM error
Lighting	Overheat discharge temperature protection

Fujitsu Air Conditioner Hardwired Remote Controller System Error Codes

When EE:EE is displayed on remote control , press “Energy Save” & “Zone Control” buttons simultaneously for longer than 3 secs. The error code will then be displayed on the LCD.

E0:00	Coms error – indoor to remote
E1:00	Coms error – indoor to outdoor
E2:00	Return air thermistor open circuit
E3:00	Return air thermistor short circuit
E4:00	Indoor coil thermistor open
E5:00	Indoor coil thermistor shorted
E6:00	Outdoor coil thermistor open
E7:00	Outdoor coil thermistor shorted
EA:00	Outdoor ambient thermistor open
Eb:00	Outdoor ambient thermistor shorted
Ec:00	Discharge pipe themistor open
Ed:00	Discharge pipe thermistor shorted
EE:00	High Pressure problem
EF:00	Discharge pipe temp. Problem – too high = short of gas

Press “Energy Save” & “Zone Control” buttons simultaneously for longer than 3 secs to return to normal operating mode
(1) Stop the air conditioner operation.
(2) Press the master control button and the fan control button simultaneously for 2 seconds or more to start the test run
(3) Press the start/stop button to stop the test run

[SELF-DIAGNOSIS]
When the error indication E:EE is displayed, follow the following items
to perform the self-diagnosis. E:EE indicates an error has occurred.

1. REMOTE CONTROLLER DISPLAY
1) Stop the air conditioner operation.
2) Press the set temperature buttons simultaneously for 5 seconds or more to start the self-diagnosis.
Refer to the following tables for the description of each error code
(3) Press the set temperature buttons simultaneously for 5 seconds or more to stop the self-diagnosis

Error code	Error contents
00	Communication error (indoor unit to remote controller)
01	Communication error (indoor unit to outdoor unit)
02	Room temperature sensor open
03	Room temperature sensor short-circuited
04	Indoor heat exchanger temperature sensor open
05	Indoor heat exchanger temperature sensor shortcircuited
06	Outdoor heat exchanger temperature sensor open
07	Outdoor heat exchanger temperature sensor shortcircuit
08	Power source connection error
09	Float switch operated
0A	Outdoor temperature sensor open
0b	Outdoor temperature sensor short-circuited
0c	Discharge pipe temperature sensor open
0d	Discharge pipe temperature sensor short-circuited
0E	Outdoor high pressure abnormal
0F	Discharge pipe temperature abnormal
11	Model abnormal
12	Indoor fan abnormal
13	Outdoor signal abnormal
14	Outdoor EEPROM abnormal

Fujitsu air conditioning fault codes Wall Mounted Single Systems ASY, ASYA & ASYB

Includes AWYZ Nokria Models

Red Light Operation	Green Light Timer
Off	2 Flashes	Reverse Comms Fail at Startup
Off	3 Flashes	Reverse Comms Fail In Use
Off	4 Flashes	Forward Comms Fail at Startup
Off	5 Flashes	Forward Comms Fail In Use
Off	8 Flashes	Wired Remote Control Failure
2 Flashes	2 Flashes	Indoor Air Sensor Fail
2 Flashes	2 Flashes	Indoor Pipe Sensor Fail
3 Flashes	2 Flashes OD	Disch Sensor Fail
3 Flashes	3 Flashes OD	Pipe Sensor Fail
3 Flashes	4 Flashes OD	Air Sensor Fail
3 Flashes	8 Flashes	Compressor Temp Sensor Fail
4 Flashes	2 Flashes	Forced Auto Switch Welded
4 Flashes	3 Flashes	Main Relay Welded
4 Flashes	4 Flashes	Power Failure
4 Flashes	7 Flashes	VDD Permament Stop Protection
4 Flashes	8 Flashes	Reverse VDD Permament Stop
5 Flashes	2 Flashes	Current Trip
5 Flashes	3 Flashes	CT Abnormal
5 Flashes	5 Flashes	Compressor Failure
5 Flashes	6 Flashes	Outdoor Fan Failure
6 Flashes	2 Flashes	ID Fan Motor Locked
6 Flashes	3 Flashes	ID Fan Motor Rotation Error
7 Flashes	2 Flashes	High Discharge Temperature
7 Flashes	3 Flashes	High Pressure
7 Flashes	5 Flashes	Pressure Switch Fail
8 Flashes	2 Flashes	Active Filter AFM Fail 1st Time
8 Flashes	3 Flashes	Active Filter AFM Fail 2nd Time
8 Flashes	4 Flashes	PFC Circuit Error
Blinking	Blinking	PCB Failure

All Other Wireless Indoor Units AUY, ABY & AWY Models Fujitsu air conditioning fault codes

Including Multi Systems (Not J Series or VRF)

Red Light operation	Green Light Timer	Yellow Light Swing	Fail
On			Normal
On	Slow Blink	Slow Blink	Test
Blinks	Blinks	Off	ID PCB Fail
Blinks	Blinks	Blinks	OD PCB Fail
Blinks	2 Pulses	Off	OD Power Connection Failure
Blinks	3 Pulses	Off	OD Unit Pipe Sensor Fail
Blinks	4 Pulses	Off OD	Unit Air sensor Fail
Blinks	4 Pulses	Blinks	OD Unit Air sensor Short
Blinks	5 Pulses	Off	OD Unit Disch Sensor Fail
Blinks	5 Pulses	Blinks	OD Unit Disch Sensor Short
Blinks	6 Pulses	Off	High Pressure
Blinks	7 Pulses	Off	High Discharge or Compressor Temp
Blinks	9 Pulses	Off	OD Unit Compressor Temp Sensor
Blinks	10 Pulses	Off	IPM Error
Blinks	11 Pulses	Off	CT Error
Blinks	12 Pulses	Off	AFM Filter Error
Blinks	13 Pulses	Off	Compressor Error
Blinks	14 Pulses	Off	OD Fan Motor Fail
2 Pulses	Blinks	Off	Air Sensor Open
2 Pulses	Blinks	Blinks	Air Sensor Closed
3 Pulses	Blinks	Off	Pipe Sensor Open
3 Pulses	Blinks	Blinks	Pipe Sensor Closed
4 Pulses	Blinks	Off	Drain Problem
5 Pulses	Blinks	Off	Communication Error
5 Pulses	Blinks	Blinks	OD PCB or Wiring Error
6 Pulses	Blinks	Off	Indoor Fan Failure

Fujitsu air conditioning fault codes Wall Mounted Multi Models

Initial Display			Further Interrogation by Pressing Test Button on Infra Red RC
Red	Green	Meaning	Red	Green	Meaning
2 Flashes	Blinks	ID Sensor Failure	Blinks	2 Flashes	ID Air Sensor
2 Flashes	Blinks	ID Sensor Failure	Blinks	3 Flashes	ID Pipe Sensor
4 Flashes	Blinks	ID Control Error	Blinks	2 Flashes	Manual Auto Button Error
4 Flashes	Blinks	ID Control Error	Blinks	4 Flashes	Power Source Failure
5 Flashes	Blinks	Comms Failure	Blinks	2 Flashes	Reverse Comms Failure
5 Flashes	Blinks	Comms Failure	Blinks	3 Flashes	Forward Comms Failure
6 Flashes	Blinks	ID Fan Failure	Blinks	2 Flashes	Motor locked
6 Flashes	Blinks	ID Fan Failure	Blinks	3 Flashes	Motor RPM Incorrect
Blinks	2 Flashes	OD Thermistor Fail	2 Flashes	Blinks	OD Discharge Sensor Fail
Blinks	2 Flashes	OD Thermistor Fail	4 Flashes	Blinks	OD Pipe Sensor Fail
Blinks	2 Flashes	OD Thermistor Fail	6 Flashes	Blinks	OD Air Sensor Fail
Blinks	2 Flashes	OD Thermistor Fail	8 Flashes	Blinks	Compressor Temp Sensor Fail
Blinks	2 Flashes	OD Thermistor Fail	9 Flashes	Blinks	2 Way Valve Sensor Fail
Blinks	2 Flashes	OD Thermistor Fail	10 Flashes	Blinks	3 Way Valve Sensor Fail
Blinks	3 Flashes	Pressure Switch	2 Flashes	Blinks	Pressure Switch
Blinks	4 Flashes	ID Units Incorrect	2 Flashes	Blinks	Incorrect Indoor Unit Index
Blinks	5 Flashes	Inverter Failure	2 Flashes	Blinks	IPM Failure
Blinks	5 Flashes	Inverter Failure	5 Flashes	Blinks	Compressor Failure

Fujitsu air conditioning Wired Remote Control Models fault codes

Code Consists of Indoor Unit Address Followed by the Fault Code
Below. No E denotes No Fault

OO	ID to RC Comms Fail
O1	ID to OD Comms Fail
O2	ID Air Sensor Open
O3	ID Air Sensor Close
O4	ID Pipe Sensor Open
O5	ID Pipe Sensor Close
O6	OD Pipe Sensor Fail
O8	Power Source Connection Failure
O9	Drain Problem Float switch operated
OA	OD Air Sensor Fail
OC	Discharge sensor Fail
OE	Outdoor High Pressure Heatsink error
11	OD PCB Fail
12	ID Fan Fail
13	OD Signal Abnormal ID signal error
14	OD EEPROM Fail
15	Compressor Temp Failure
16	Pressure Switch Error
17	IPM Error
18	CT Error
19	Active Filter Module Error
1A	Compressor Failure
1B	OD Fan Failure
1C	Inverter to PCB Comms Fail
1D	2 Way Valve sensor Fail
1E	Expansion Valve Error
1F	Connection ID Unit Error
20	Indoor manual switch abnormal
24	Excessive high pressure protection on cooling
25	PFC circuit error
26	Indoor signal error
27	Indoor signal error
28	Indoor heat exchanger temperature error
29	Outdoor heat exchanger temperature (middle) error
2A	Power supply frequency detection error
2B	Compressor temperature error
2C	Four-way valve abnormal

Outdoor PCB Fault Codes

Inverter OD Unit PCBs (1 red LED)			Non Inverter OD PCBs (2 red LEDs)
OD PCB LED			LED 1	LED 2
Pulses	Models 9-30	Models 36-54	Blinks	Blinks	OD PCB Fail
1	Comms Failure	Comms Failure	1 Pulse	Lift	Power Source Failure
2	Disch Sensor Fai	Disch Sensor Fai	2 Pulses	Lift	OD Disch Temp Sensor
3	Pipe Sensor Fail	Pipe Sensor Fail	3 Pulses	Lit	OD Pipe Sensor
4	Air Sensor Fail	Air Sensor Fail	4 Pulses	Lit	OD Air Sensor
5	2 Way Valve Sensor		5 Pulses	Lit	Comms Failure
6	3 Way Valve Sensor		6 Pulses	Lit	Indoor Unit Error
7	Compressor Thermistor	Compressor Thermistor	7 Pulses	Lit	High Discharge Temp
8	Pressure Switch	Heatsink Sensor Fail	8 Pulses	Lit	High Pressure
9	Indoor Comms Error	Pressure Switch	9 Pulses	Lit	Compressor Temp Abnormal
10	Current Trip		10 Pulses	Lit	Compressor Temp Sensor Fail
11	CT Fail
12	Compressor Position Fail	IPM Error
13	Compressor Start Fail	Compressor Position Fail
14	Timer Failure	Compressor Start Fail
15		OD Upper Fan Fail
16		OD Lower Fan Fail
Slow Blink		Protect Operation