In this complete LG error code guide, we’ll show you the different codes and possible causes affecting LG aircon units — and how you can use them to check and troubleshoot the common issues with your LG air conditioner.
LG Air Conditioner Error Codes: The Complete List
Indoor Unit Faults
| Error Code | Possible Cause |
|---|---|
| 1 | Indoor unit room temperature sensor error |
| 2 | Indoor unit inlet pipe sensor error |
| 4 | Float switch error (optional) |
| 5 | Communication error between indoor unit and outdoor units |
| 6 | Indoor unit outlet pipe sensor error |
| 9 | Indoor unit EPROM error |
| 10 | Indoor unit BLDC motor fan lock |
| 12 | Indoor unit middle pipe sensor error |
Outdoor Unit Faults
| Error Code | Possible Cause |
|---|---|
| 21 | DC Peak (IPM Fault); Compressor DC voltage was too high |
| 22 | Current Transformed (CT2) error; Alternating current (AC) input too high |
| 23 | DC Link Low Volt |
| 25 | AC Low/High Volt |
| 26 | DC Comp Position Error (not providing rotation), Locking |
| 27 | PSC Fault; Current to inverter compressor between AC and DC converter circuit too high |
| 28 | Inverter compressor DC voltage is too high |
| 29 | Inverter compressor amperage is too high |
| 31 | Current-to-current transformer (CT) thermistor is too low |
| 32 | Inverter Compressor Discharge Pipe (D-Pipe) Overheat |
| 40 | CT Sensor Error; Thermistor is disconnected or shorted out |
| 41 | D-Pipe Sensor INV is disconnected or shorted out |
| 44 | Outdoor Air Sensor is disconnected or shorted out |
| 45 | Middle thermistor of outdoor unit condenser coil is disconnected or shorted out |
| 46 | Outdoor unit suction line thermistor is disconnected or shorted out |
| 48 | Outdoor unit coil outlet (liquid line) thermistor is disconnected or shorted out |
| 53 | Communication failure from outdoor unit to indoor unit |
| 60 | Outdoor unit printed circuit board (PCB) EPROM check sum error |
| 61 | Outdoor unit condenser coil temperature is too high |
| 62 | Outdoor unit inverter compressor PCB heat sink temperature is too high |
| 63 | Condenser coil pipe thermistor temperature is too low |
| 65 | Heat sink thermistor has disconnected or has shorted out |
| 67 | Outdoor brushless direct current (BLDC) fan motor lock error |
LED Error Codes
| Error Code | Description | LED 01G/M (Red) | LED 01G/M (Red) | Possible Cause |
|---|---|---|---|---|
| 21 | DC Link Peak (IPM Fault) | 2 times 3 | 1 times 3 | Over Rated Current |
| 22 | CT 2 (Max CT) | 2 times 3 | Input Over Current | |
| 23 | DC Link Low Volt. DC Link High Volt. |
3 times 3 | DC Link Volt is below 140Vdc DC Link Volt is above 420Vdc |
|
| 25 | Low Voltage/Over Voltage | 5 times 3 | Abnormal AC Volt Input | |
| 26 | DC Compressor Position Error | 6 times 3 | Compressor Starting Fall Error | |
| 27 | PSC/PFC Fault Error | 7 times 3 | Over Inverter PCB input current | |
| 29 | COMP Over Current | 9 times 3 | Over Inverter Compressor Current | |
| 32 | D-Pipe High | 3 times 3 | 2 times 3 | D-Pipe Temp. High |
| 35 | Low Pressure Error | 5 times 3 | Excessive decrease of Low Pressure | |
| 39 | Communication Error | 9 times 3 | Communication Error Between PFC Micom and INV Micom | |
| 40 | CT Sensor (Open/Short) | 4 times 3 | 0 | CT Circuit Malfunction |
| 41 | INV. D-Pipe Th Error | 1 times 3 | Open/Short | |
| 43 | High Pressure Sensor Error | 3 times 3 | ||
| 44 | Outdoor Air Th Error | 4 times 3 | ||
| 45 | Cond. Mid-Pipe Th Error | 5 times 3 | ||
| 46 | Suction Pipe Th Error | 6 times 3 | ||
| 48 | Cond. Out-Pipe Th Error | 8 times 3 | ||
| 51 | Capacity Over | 5 times 3 | 1 times 3 | Over combination |
| 53 | Signal Error (Indoor <-> Outdoor) | 3 times 3 | Communication Poorly | |
| 54 | 3-Phase Wrong wiring | 4 times 3 | 3-Phase Wrong Wring of Outdoor Unit (Reverse Phase/Omission of Phase) | |
| 60 | EEPROM Check Sum Error | 6 times 3 | 0 | Check Sum Mismatching |
| 61 | Cond. Pipe Th High | 1 times 3 | Cond. Temp. High | |
| 62 | Heat sink Th High | 2 times 3 | Heatsink Temp. High | |
| 65 | Heat sink Th Error | 5 times 3 | Open/Short | |
| 67 | Outdoor BLDC Fan Lock | 7 times 3 | Outdoor Fan is not operation | |
| 73 | PFC Fault Error(SAN) | 7 times 3 | 3 times 3 | Over Current of Outdoor Unit PFC |
Error Codes with Possible Causes
| Error Code | Description | Possible Cause | Check point and normal condition |
|---|---|---|---|
| 1 | Indoor air sensor | • Open / Short • Soldered poorly • Internal circuit error |
Normal resistor: 10KS2/ at 25°C (Unplugged) Normal voltage : 2.5Vdc / at 25°C (plugged) |
| 2 | Indoor inlet pipe sensor | • Open / Short • Soldered poorly |
Normal resistor: 5K£2/ at 25°C (Unplugged) Normal voltage : 2.5Vdc / at 25°C (plugged) |
| 6 | Indoor outlet pipe sensor | • Internal circuit error | - |
| 3 | Communication | • Open / Short | • Connection of wire |
| 3 | Wired R/C | • Wrong connection | • Main PCB Volt. DC 12V • Noise interference |
| 4 | Drain pump/Float switch | • Float switch Open. (Normal: short) | • The connection of wire(Drain pump/ Float switch) • Drain pump power input. (220V) • Drain tube installation. • Indoor unit installation. (Inclination) |
| апр.53 | Communication (Indoor - Outdoor) | • Communication poorly | • Power input AC 220V. (Outdoor, Indoor) • The connector for transmission is disconnected. • The connecting wires are misconnected. • The GND1,2 is not connected at main GND. • The communication line is shorted at GND. • Transmission circuit of outdoor PCB is abnormal. • Transmission circuit of indoor PCB is abnormal. |
| 21 | DC Peak | • Instant over current • Over Rated current • Poor insulation of IPM |
• An instant over current in the U,V,W phase - Comp lock - The abnormal connection of U,V,W • Over load condition - Overcharging of refrigerant - Pipe length. • Poor insulation of compressor |
| 22 | Max. C/T | Over current (14A) | Malfunction of compressor Blocking of pipe Low voltage input Refrigerant, pipe length, blocked |
| 40 | CfT Internal circuit | Initial current error | Malfunction of current detection circuit. (Open / Short) The voltage of “C01N" Is 4.0Vdc(25A). |
| 23 | DC Link | • DC link volt, is 140Vdc. | • Check the power source. |
| 23 | Low voltage. | - | • Check the components. |
| 28 | DC Link High voltage | • DC link volt, is 420Vdc T | - |
| 24 | Press S/W Open | • Low / High press | • Check the connection of “CN_Press”. • Check the components. |
| 25 | Input voltage | • Abnormal Input voltage | • Check the power source. • Check the components. |
| 26 | DC Compressor Position | • Compressor position detect error | • Check the connection of comp wire “U,V,W” • Malfunction of compressor • Check the component of “IPM", detection parts. |
| 27 | PSC Fault | • Over current at "IGBT" | • Check the component of “IGBT". • Check the components. |
| 32 | D-pipe (Inverter) temp, high (105°C t) | • Discharge sensor (Inverter) temp, high | • Check the discharge pipe sensor for INV. • Check the install condition for over load. • Check the leakage of refrigerant. • Check the SVC V/V open. |
| 33 | D-pipe (Constant) temp, high (105°C I) | • Discharge sensor (Cons.) temp, high | • Check the discharge pipe sensor for Cons. • Check the install condition for over load. • Check the leakage of refrigerant. • Check the SVC V/V open. |
| 41 | D-pipe sensor (Inverter) | • Open / Short • Soldered poorly • Internal circuit error |
• Normal resistor: 200K£2 / at 25°C (Unplugged) • Normal voltage : 4.5Vdc / at 25°C (plugged) |
| 44 | Air sensor | - | • Normal resistor: 10K£2 / at 25°C (Unplugged) • Normal voltage : 2.5Vdc / at 25°C (plugged) |
| 45 | Condenser Pipe sensor | - | • Normal resistor: 5K£2 / at 25°C (Unplugged) |
| 46 | Suction Pipe sensor | - | • Normal voltage : 2.5Vdc / at 25°C (plugged) |
| 47 | D-pipe sensor (Constant) | - | • Normal resistor: 200K£2 / at 25°C (Unplugged) • Normal voltage : 4.5Vdc / at 25°C (plugged) |
| 65 | Heat sink sensor | - | • Normal resistor: 10K£2 / at 25°C (Unplugged) • Normal voltage : 2.5Vdc / at 25°C (plugged) |
| 51 | Over capacity | • Over capacity | • Check the indoor unit capacity. • Check the combination table. |
| 60 | EEPROM Check sum | • Check sum error | • Check the PCB ASM P/No. • Check the poor soldering. |
| 61 | Condenser pipe sensor temp, high | • Condenser pipe sensor detected high temp.(65°C) | • Check the load condition. • Check the sensor of Condenser pipe sensor. |
| 62 | Heat sink sensor temp, high | • Heat sink sensor detected high temp.(85°C) | • Check the fan is locked. • Check the sensor of heat sink. |
| май.53 | Title Communication (Indoor - Outdoor) | • Communication poorly | • Power input AC 220V. (Outdoor, Indoor) • The connector for transmission is disconnected. • The connecting wires are misconnected. • The communication line is shorted at GND. • Transmission circuit of outdoor PCB is abnormal. • Transmission circuit of indoor PCB is abnormal. |
| 21 | DC PEAK (IPM Fault) | • Instant over current • Over Rated current • Poor insulation of IPM |
• An instant over current in the U,V,W phase - Comp lock - The abnormal connection of U,V,W • Overload condition - Overcharging of refrigerant Pipe length. Outdoor Fan is stop • Poor insulation of compressor |
| Error Code | Possible Cause | Indicator | Operating State |
|---|---|---|---|
| 2 | Outdoor TH. is short or open. | The operating LED will be blinking twice. | Keep operating state. |
| 4 | Temp. of Heat sink is over 95°C. Heat sink TH. is short or open. | The operating LED will be blinking 4 times. | Restart compressor when Heat sink Temp is 85°C below. |
| 5 | Communication error (serial communication). | The operating LED will be blinking 5 times. | The operation is off (enable to restart by remote controller). |
| 6 | DC peak error. | The operating LED will be blinking 6 times. | Compressor will be turned off immediately (not enable to restart by remote controller) |
| 7 | Running current is overloaded. | The operating LED will be blinking 7 times. | Compressor will be turned off immediately (not enable to restart by remote controller) |
| 9 | Outdoor fan lock error (BLDC fan model) | The operating LED will be blinking 9 times. | The operation is off (enable to restart by remote controller). |
| 10 | D-PIPE TH is short or open. | The operating LED will be blinking 10 times. | Compressor will be turned off immediately (restart compressor when D-PIPE TH. is recovered) |
| Error Code | Possible Cause | Check/Repair | Shop Parts |
|---|---|---|---|
| 1 | Temperature sensor failure | Unplug the air conditioner and check the wire harness connections on the electronic control board. Examine the electronic control board for damage. Check for a pinched or broken wire in the temperature sensor wire harness. Replace the temperature sensor if it’s defective. | Temperature sensor, Wire harness, Electronic control board |
| E2 | Failure in the indoor temperature sensor | Unplug the air conditioner and check the wire harness connections on the electronic control board. Examine the electronic control board for damage. Check for a pinched or broken wire in the indoor temperature sensor wire harness. Replace the indoor temperature sensor if it’s defective. | Indoor temperature sensor, Wire harness, Electronic control board |
| E3 | Abnormal operation protection error | Indoor temperature sensor, Wire harness, Electronic control board | |
| E3 | Clean or replace filters if dirty. Unplug the window air conditioner and check all components for visible damage. Check fan blades for damage or obstructions and replace any damaged fan blades. Check all wire harness connections. Replace any damaged wire harnesses. | Filter, Fan blade, Fan motor, Wire harness | |
| E4 (Portable A/C only) | The air conditioner is in the defrost mode | After the air conditioner exits defrost mode and resume normal operation, check the unit to see if it’s cooling properly. If so, then the E4 code is normal. If the portable air conditioner frequently goes into the defrost mode and isn’t cooling properly, check the air filters and clean or replace filters if dirty. | Filter |
| P2 or FL (Portable A/C only) | The water collection tank is full | Empty the water collection tank. If the P2 or FL code appears when the tank is empty, replace the float switch or sensor in the collection tank. | Collection tank float switch or sensor |
Error Codes with Description
| Error Code | Function Name | Description |
|---|---|---|
| 01 h | Read Coil Status | Run/Stop(status), Lock(status), Swing(status), Alarm, Filter Sign(status), Mode Lock(status), Wind Flow Lock(status) |
| 03h | Read Holding Registers | Operation Mode(status), Fan Speed(status), Room Temperature, Error Code, Set Room Temperature(status), Set Lower Temperature(status), Set Upper Temperature(status), User Mode(status) |
| 05h | Force Single Coil | Run/Stop(setting), Lock(setting), Swing(setting), Filter Sign Reset, Mode Lock(setting), Wind Flow Lock(setting) |
| 06h | Preset Single Registers | Operation Mode(setting), Fan Speed(setting), Set Room Temperature(setting), Set Lower Temperature(setting), Set Upper Temperature(setting), User Mode(setting) |
Other Error Codes
| Error Code | Possible Cause | Solution |
|---|---|---|
| Code appears in the display. F1,F2 or F3 | Air conditioner is in FAN mode and the number shown is the set fan speed. | This is normal. The air conditioner is working properly. |
| FL | The water collection tank is full. | Empty the water collection tank. |
| CH01 | Short or open circuit in the indoor air thermistor. | Unplug the air conditioner and contact your authorized LG service center. |
Also read: Carrier AC Error Codes
We are a well-established air conditioning service and repair company based in Singapore. Our technicians, with years of expertise, are capable of servicing various air conditioner models. Trust us to identify and address any issues with your air conditioner effectively.
If you have other problems with your LG air conditioning unit, then you can check out our article about LG aircon troubleshooting.
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