Indoor Unit Faults:
| Error Codes | Problems | Causes | Indoor Unit Status |
| CH01 | Air sensor Problem | Open / Short circuit | Off |
| CH02 | Inlet Pipe Sensor Problem | Open / Short circuit | Off |
| CH03 | Communication Error between wire controller remote – IDU | Communication Poor | Off |
| CH04 | Drain Pump Problem | Float switch Open circuit (High-level water alarm) | Off |
| CH05 | Communication problem between IDU – ODU | Communication Poorly | Off |
| CH06 | Outlet pipe sensor problem | Open / Short circuit | Off |
| CH07 | Different Operation Mode | Indoor units are set in different operation modes | Off |
| CH09 | Checksum Error | Defective PCB or EEPROM Connections | Off |
| CH10 | Indoor Motor Fan Lock | Fan Motor or PCB Defective | Off |
| HL | Hard Lock (Controlled by External Source) | Controlled by Dry Contact or Central Controller | Off |
| CL | Child Lock Function On | Not an error, press the Timer & Min buttons for 3 sec to toggle On/Off | On |
| Po | Jet Cool Mode On | Not an error, press the Jet Cool button to toggle On/Off | On |
Outdoor Unit Faults:
| Error Codes | Problems | Causes | LED Red | LED Green | Outdoor Status |
| CH21 | IPM Problem | Compressor malfunction, IPM Fault | 2 times | 1 time | Off |
| CH22 | CT 2 (Max Current) | Current is 14A ↑ | 2 times | 2 times | Off |
| CH23 | DC Link Low Volt. | DC Link volt. Is 140V ↓ | 2 times | 3 times | Off |
| CH24 | Low / High Pressure | Low / High press switch OPEN | 2 times | 4 times | Off |
| CH25 | AC Low / AC High Volts | Abnormal AC volt. Input. | 2 times | 5 times | Off |
| CH26 | DC Compressor Position | – | 2 times | 6 times | Off |
| CH27 | PSC Fault (Reactor) | – | 2 times | 7 times | Off |
| CH28 | DC Link High Volts | Off | 2 times | 8 times | Off |
| CH29 | Compressor Over Current Problem | Inverter Compressor input current is over 30A |
2 times | 9 times | Off |
| CH32 | High Discharge Pipe Temperature (INV) | D-Pipe Temp (Inv.) >105°C | 3 times | 2 times | Off |
| CH33 | High Discharge Pipe Temperature | D-Pipe Temp (Const) >105°C | 3 times | 3 times | Off |
| CH34 | Safety Relay | Power down due to the abnormal pressure in the sealed unit | – | – | Off |
| CH39 | Communication Error | Communication Error Between PFC and INV PCB |
3 times | 9 times | Off |
| CH40 | CT Circuit Problem | CT Circuit malfunction | 4 times | Off | |
| CH41 | D-Pipe sensor INV | Open / Short circuit. | 4 times | 1 time | Off |
| CH44 | Air sensor (Open/Short) | Open / Short circuit | 4 times | 4 times | Off |
| CH45 | Cond. Pipe Sensor | Open / Short circuit | 4 times | 5 times | Off |
| CH46 | Suction Pipe Sensor Problem | Open / Short circuit | 4 times | 6 times | Off |
| CH47 | D-pipe Sensor Cons. | Open / Short circuit | 4 times | 7 times | Off |
| CH48 | D-Pipe & Air Sensor | Dual Sensor unplugged | 4 times | 8 times | Off |
| CH50 | Outdoor unit phase connection error | – | – | – | Off |
| CH51 | Over Capacity | Over Load Combination | 5 times | 1 time | Off |
| CH52 | Communication Error (Main micom↔Sub micom) | Poor/Loss of Communication | 5 times | 2 times | Off |
| CH53 | Communication Error (Indoor ↔ Outdoor) |
Poor/Loss of Communication | 5 times | 3 times | Off |
| CH54 | Outdoor 3-Phase Problem Reverse / Missing Phase |
Incorrect Wiring Problem | 5 times | 4 times | Off |
| CH60 | EEPROM Check Sum | Check Sum Mis-Match | 6 times | Off | |
| CH61 | Cond. Pipe Sensor Temp. High | High Condenser Temperature | 6 times | 1 time | Off |
| CH62 | Heat Sink Sensor Temp. High | High Heat Sink Temperature | 6 times | 2 times | Off |
| CH63 | Cond. Pipe Sensor Temp. Low | Low Condenser Temperature | 6 times | 3 times | Off |
| CH65 | Heat Sink Sensor (Open/Short) | Open / Short circuit | 6 times | 5 times | Off |
| CH67 | Outdoor BLDC Fan Lock | Fan Motor/Circuit Problem | 6 times | 7 times | Off |
| CH73 | PFC Fault Error (S/W) | Inverter PCB input current is over 48A (Peak) for 2ms | 7 times | 3 times | |
| CH83 | Check Refrigerant | Gas Leakage | – | – | On |
| CH105 | Communication Error (Mainboard ↔Fan board) | Poor or Loss of Communication | 6 times | 5 times | Off |
LG Room AC Error Codes
| Error Codes | Description | Causes | AC Unit Status |
| P2 or FL | Depending on the model indicate that the drain pan in the unit is full | Blockage of dirt or too much humidity | On |
| CH34 | Safety Relay | Due to abnormal pressure in the sealed system | Off |
| E1 or CH02 | Auto Stop Protection | Indoor Pipe Sensor Open/Short Condition | Off |
| E2 or Ch01 | Auto Stop Protection | Indoor Air Sensor Open/Short Condition | Off |
| E3 or CH03 | No Refrigerant | Refrigerant Leakage | Off |
| E4 | Defrosting Mode | Not an Error Defrosting the ice | Off |
| E5 | Water Collection Tank Full | Drain Water from the tank | Off |
| F1 | Fan Speed | Not am Error | On |
| F2 | Fan Speed | Not an Error | On |
| F3 | Fan Speed Level 3 | Not an Error | On |
LG Inverter Air Conditioner Error Codes List
For Standard Wall-Mounted High-Efficiency Single Zone Systems [ Model- LS091HSV & LS121HSV ]
| Error Codes | Description | LED Green |
LED Red |
| 1 | The indoor unit return air thermistor has disconnected or has shorted out | 1X | – |
| 2 | The indoor unit inlet pipe thermistor has disconnected or has shorted out | 2X | – |
| 5 | Communication failure from the indoor unit to the outdoor unit | 5X | – |
| 6 | The indoor unit inlet pipe thermistor has disconnected or has shorted out | 6X | – |
| 9 | Indoor unit EEPROM error | 9X | 1X |
| 10 | The indoor unit fan has locked up (fan motor operation failure) | – | 1X |
| 12 | The indoor unit middle pipe thermistor has disconnected or has shorted out | 2X | 1X |
| 21 | DC peak error/IPM fault; compressor DC voltage was too high | 2X | 1X |
| 22 | Current transformer2 (CT2) error, AC input current is too high | 2X | 2X |
| 23 | DC link voltage is too low | 2X | 3X |
| 25 | The voltage to the system is too low or too high | 2X | 5X |
| 26 | Inverter compressor has seized up or is not providing rotation | 2X | 6X |
| 27 | Prospective short circuit (PSC) fault error, current to inverter compressor between AC and DC converter circuit is too high | 2X | 7X |
| 28 | Inverter compressor DC voltage is too high | 2X | 8X |
| 29 | Inverter compressor amperage is too high | 2X | 9X |
| 31 | Current the current transformer (CT) thermistor is too low | 3X | 1X |
| 32 | Inverter compressor discharge pipe temperature is too high | 3X | 2X |
| 40 | The current transformer (CT) thermistor has disconnected or has shorted out | 4X | – |
| 41 | Inverter compressor discharge pipe thermistor has disconnected or has shorted out | 4X | 1X |
| 44 | The outdoor unit inlet air thermistor has disconnected or has shorted out | 4X | 4X |
| 45 | Outdoor unit condenser coll middle thermistor has disconnected or has shorted out | 5X | 5X |
| 46 | The outdoor unit suction line thermistor has disconnected or has shorted out | 4X | 6X |
| 48 | Outdoor unit coll outlet (liquid line) thermistor has disconnected or has shorted out | 4X | 8X |
| 53 | Communication failure from the outdoor unit to the indoor unit | 5X | 3X |
| 60 | Outdoor unit PCB EEPROM checksum error | 6X | – |
| 61 | The outdoor unit condenser coil temperature is too high | 6X | 1X |
| 62 | Outdoor unit inverter compressor PCB heat sink temperature is too high | 6X | 2X |
| 63 | Condenser coil pipe thermistor temperature is too low | 6X | 3x |
| 65 | The heat sink thermistor has disconnected or has shorted out | 6X | 5X |
| 67 | Outdoor BLDC fan motor lock error | 6X | 7X |