Mitsubishi Electric Air Conditioner Error Codes

Error Codes and Troubleshooting for Mitsubishi Electric Air Conditioners

The list below features all the malfunction error codes for Mitsubishi Electric air conditioners and their potential causes.  You may determine the state and problem of the air conditioner or air conditioning system by looking up the error code.

Mitsubishi Electric air conditioner error codes

Mitsubishi Electric 4 Digit Air Conditioner Error Codes

Error Code NumberAir Conditioner Fault Description
0403Serial communication error
0900Test run
1102Discharge temperature fault
1301Low pressure fault
1302High pressure fault
1500Refrigerant overcharge
2500Drain sensor submergence
2502Drain pump fault
2503Drain sensor fault
2600Water leak
4102Open phase
4106Transmission power supply fault
4115Power supply signal sync error
4116RPM error/Motor error
4220Abnormal bus voltage
4225Low bus voltage
4230/4260Heatsink overheat protection activated
4240Overload protection activated
4250Overcurrent protection activated
4255Outdoor unit fan error
5101Temperature sensor fault
5102Return air thermistor fault
5110Outdoor unit inverter heatsink thermistor error
5201Pressure sensor fault
5301Current sensor fault
5701Loose float switch
6201Remote controller issue
6600Address overlap
6601Polarity setting error
6602Transmission processor hardware error
6603Transmission line busy
6606Communication fault
6607No ACK
6608No response
6831/6834MA controller signal reception error
6832/6833MA controller comms fault
7100Total capacity error
7101Capacity code setting error
7102Wrong number of connected units
7105Address setting error
7106Attribute setting error
7110Signal transmission error
7111Remote controller sensor fault
7113Function setting error
7117Model setting error
7130Incompatible unit combination

General Mitsubishi Electric Air Conditioner Error Codes

Error Code Number and LetterAir Conditioner Fault Description
P1Intake sensor error
P2 P9Pipe (Liquid or 2-phase pipe) sensor error
E6 E7Indoor/outdoor unit communication error
P4Drain sensor error
P5Drain pump error
PAForced compressor error
P6Freezing/Overheating safeguard operation
EECommunication error between indoor and outdoor units
P8Pipe temperature error
E4Remote controller signal receiving error
FbIndoor unit control system error (memory error, etc.)
E0 E3Remote controller transmission error
E1 E2Remote controller control board error
E9Indoor/outdoor unit communication error (Transmitting error) (Outdoor unit)
UPCompressor overcurrent interruption
U3, U4Open/short of outdoor unit thermistors
UFCompressor overcurrent interruption (When compressor locked)
U2Abnormal high discharging temperature/49C worked/insufficient refrigerant
U1 UdAbnormal high pressure (63H worked)/Overheating safeguard operation
U5Abnormal temperature of heat sink
U6Compressor overcurrent interruption/Abnormal of power module
U7Abnormality of superheat due to low discharge temperature
U8Outdoor unit fan safeguard stop
U9UH Abnormality such as overvoltage or voltage shortage and abnormal synchronous signal to the main circuit/ Current sensor error.

Mitsubishi Electric Air Conditioner Error Codes

Error Code Number and LetterAir Conditioner Fault Description
EAError detail Miswiring of indoor/outdoor unit. exceed the number of indoor unit connections.
EBError detail Miswiring of indoor/outdoor unit. (miswiring disconnection)
ECError detail Start-up time over
E6Error detail Indoor/outdoor unit transmission error (signal receiving error)
E7Error detail Indoor/outdoor unit transmission error (transmitting error)
E8Error detail Indoor/outdoor unit transmission error (signal receiving error)
E9Error detail Indoor/outdoor unit transmission error (transmitting error)
E0Error detail Remote control transmission error (signal receiving error)
E3Error detail Remote control transmission error (transmitting error)
E4Error detail Remote control transmission error (signal receiving error)
E5Error detail Remote control transmission error (transmitting error)
EFError detail M-NET transmission error
EDError detail Serial transmission error
P1Error detail Abnormality of room temperature thermistor (TH1)
P2Error detail Abnormality of pipe temperature thermistor/liquid (TH2)
P4Error detail Abnormality of drain sensor (DS)
P5Error detail Malfunction of drain-up machine
P6Error detail Freezing/overheating protection detect
P8Error detail Abnormality of pipe temperature
P9Error detail Anormality of pipe temperature thermistor/condenser/evaporator (TH5)
F1Error detail Reverse phase detection
F2Error detail L3 open phase detection
F3Error detail 63L connector open
F4Error detail 49C connector open
F7Error detail Reverse phase detection circuit (p.c.board) fault
F8Error detail Input circuit fault
F9Error detail Connector 2 or more open
FAError detail L2-phased open phase or 51CM connector open
U2Error detail Abnormal high discharging temperature
U2Error detail Inner thermostat (49C) operation
U1Error detail Abnormal high pressure (high pressure swicth 63H worked)
U1Error detail Direct cut operation
UEError detail High pressure error (ball valve closed)
ULError detail Abnormal low pressure
UDError detail Overheat protection
U6Error detail Compressor over current (overload) cut off
UAError detail Compressor over current (terminal relay operation)
UFError detail Compressor over current (start-up locked) cut off
UFError detail Compressor over current (operating locked) cut off
UHError detail Current sensor error
U3Error detail Discharge thermistor short/open
U4Error detail Outdoor thermistor short/open
Mr.Slim K-controlDisplay of remote controller
LED E0Diagnosis of malfunction Transmitting/receiving signal error
LED P1Diagnosis of malfunction Intake air sensor abnormal
LED P2Diagnosis of malfunction Pipe sensor abnormal
LED P3Diagnosis of malfunction System error (transmitting/receiving signal)
LED P4Diagnosis of malfunction Drain sensor abnormal
LED P5Diagnosis of malfunction Malfunctioning of the drain overflow protecting mechanism
LED P6Diagnosis of malfunction Abnormality of the coil frost/overheating protection mode
LED P7Diagnosis of malfunction System error (address)
LED P8Diagnosis of malfunction Outdoor unit malfunction
Mr.Slim K-controlPUH-EK Outdoor unit
LED ONOperation status
LED FlashCheck code display
LED LD1LED ON Compressor directiveLED Flash Reverse phase detect
LED LD2LED ON Heating directiveLED Flash Open phase detect
LED LD3LED ON During 63H1 operationLED Flash Pipe sensor short/open
LED LD4LED ON Compressor ONLED Flash High pressure switch (63H2) operation
LED LD5LED ON Outdoor fan ONLED Flash Over current relay (51CM) operation
LED LD6LED ON 4-way valve ONLED Flash Thermal switch (26C) operation
LED LD7LED ON Bypass valve ONLED Flash Thermistor (TH3) overheat protection
LED LD8LED ON Crankcase heater ONLED Flash Defective input

Mitsubishi Electric Air Conditioner Error Codes

Error Code Letter and NumberAir Conditioner Fault Description
EODuring individual unit control:Bad contact of transmission wireSignal transmitting/receiving circuits are abnormal
P1Bad contact with the thermistorDamaged thermistor
P2Bad contact with the thermistorDamaged thermistor
P3Bad contact of transmission wireSignal transmitting/receiving circuits are abnormalWrong operation due to noise wave emitted by other appliances
P4Bad contact of transmission wireDamaged thermistor
P5Malfunction of the drain pumpDamaged drain sensor
P6Short cycle of air cycleDirty air filterDamaged fanAbnormal refrigerant
P7Wrong address-settingSignal transmitting/receiving circuit of the remote controller is abnormalWrong SW6-setting
P8Wrong wiring of indoor/outdoor connecting wireReversed phaseThe protection device is workingDamaged outdoor coil thermistor

General Mitsubishi Electric Air Conditioner Problems

Mitsubishi Electric Air Conditioner Not Heating

First check all the not cooling issues as these are interchangable.
Standby showing on control panelThe air conditioner must warm up the coils when it is set to heating mode. This is standard functioning, and it lasts for around five to ten minutes after which the device starts heating normally. While the equipment is on standby, do not switch it off as this will just prolong the procedure.
Defrost or Standby showing on control panelThe temperature of the external coil in a heat pump system can drop significantly while it is heating. Frost can occasionally build up on the coil. To get rid of this frost from the coil, the machine has to periodically enter “defrost” mode. After this procedure, which typically takes five to ten minutes, the machine will resume its regular functions. To avoid this procedure, do not try to switch the machine off and on again; it will just reset and begin the “defrost” process once more.
Blowing cool air when onBecause the ceiling duct is located in the surrounding air. The interior fan will release this unconditioned air through the outlets when the device is switched on. This is standard procedure and shouldn’t take longer than a minute or two.

Air Conditioner Not Cooling

If your air conditioner is operating but it doesn’t seem to be cooling there are various symptoms.
Filter BlockedClean or replace the return air filter.
There a too many zones on at onceThe majority of ducted systems are zoned and made to operate as many places as possible. Switch off any unused, superfluous zones.
There is a low refrigerant warningRefrigerant might progressively leak over time as a result of aging or improper installation. A professional is required to fix the leak and add refrigerant, if feasible.
Faulty PartThere may be a fault with a part such as an electronic control board, fan motor or even the compressor. This will need to be diagnosed by a technician.
Hot air is blowing when the AC unit is on.Because the ductwork is often located in a heated roof space in a standard ducted air conditioner installation. When the fan runs, the heated air is released via the outlets. This is standard procedure and should take no more than a minute or two.
Air Conditioner Has No Power
Please check the following if your air conditioner won’t power on at all or if your control panel doesn’t have any display on the LCD screen.Verify that the air conditioning unit’s circuit breaker in your meter box is turned on. Re-turn the circuit breaker on if it has tripped. A professional is required to investigate if the circuit breaker trips often, indicating a power problem.Verify that the unit’s isolating switch, which is often found on the wall adjacent to the outside unit, is turned on. An electrician must inspect and replace the isolating switch if there is a problem with it, such as if it is loose or difficult to move.
Air Conditioner Has No Airflow
There may be several reasons why specific parts of your house aren’t getting any air.A malfunctioning motor damper would be the most frequent reason. This valve regulates the airflow by turning it on or off. The removal and replacement of this motor damper would depend on its kind.It’s possible that workers who have recently been in your ceiling area have ripped, split, or moved a duct from a collar and neglected to replace it.
Air Conditioner is Leaking Water
Condensation is produced by the refrigeration cycle of the air conditioner, depending on how it operates. Depending on whether the external unit is being heated or cooled, this water condensation is removed.When the outdoor unit is in the heating mode, condensation forms at the coil and needs to be drained from beneath. Since this is how things normally work, there is no need to be alarmed.In order to remove water from the inside unit during cooling operation, a condensate drain is built. Normally, this water is sent to a roof gutter. It is best to take care of this drain before turning on the cooling system since it may become clogged, break, or become dislodged, causing water to leak into the space above your ceiling.
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Mitsubishi Electric Split Air Conditioning

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Mitsubishi Electric Ducted Air Conditioning

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Other Air Conditioner Error Codes

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