Model reference
LG ARNU18GB2G1
Air Conditioner
1 document152 error codes9 service modes
Available documentation
Service Manual
- Air Conditioner Service Manual374 pg
MyPros+ Max
Diagnose your LG ARNU18GB2G1.
- Step-by-step diagnostics from the service manual
- Test values, resistance specs, and wiring references
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Error codes (152)
CodeMeaning
01Indoor unit air temperature sensor is open or short circuit.02Indoor unit inlet pipe temperature sensor is open or short circuit.03Transmission error between wired remote controller and indoor unit; failing to…04Drain pump malfunction; float switch open due to rising condensate water level.05Transmission error between outdoor unit and indoor unit; failing to receive…06Indoor unit outlet pipe temperature sensor is open or short circuit.07Different operation mode between indoor unit and outdoor unit.09Indoor unit EEPROM error; serial number marked on EEPROM is 0 or FFFFFF.10Indoor unit BLDC fan motor failure; fan motor feedback signal absent for 50…100Over-increase of discharge temperature of constant speed compressor 1 of sub1…101Over-increase of discharge temperature of constant speed compressor 2 of sub1…102Over-increase of discharge temperature of constant speed compressor 1 of sub2…103Over-increase of discharge temperature of constant speed compressor 2 of sub2…104Transmission error from sub1 outdoor unit to main outdoor unit; failing to…105Transmission error between outdoor main PCB and fan PCB (fan to main direction).106Over-current of main outdoor fan motor (inverter fan IPM fault).107Low voltage of main outdoor fan motor; DC voltage charging failure of inverter…108Transmission error between main PCB and fan PCB (fan to outdoor, outdoor to…109High pressure switch of sub1 outdoor unit has tripped.11Indoor unit transmission error; indoor unit does not receive signal from…110Reverse connection or missing phase of 3-phase power of sub1 outdoor unit.111Transmission error from main outdoor unit to sub1 outdoor unit; sub1 cannot…113Outdoor unit liquid pipe (condenser) temperature sensor of main unit is open or…114Subcooling inlet temperature sensor of main outdoor unit is open or short.115Subcooling outlet temperature sensor of main outdoor unit is open or short.116High pressure sensor of sub1 outdoor unit is open or short.117Low pressure sensor of sub1 outdoor unit is open or short.118Air temperature sensor of sub1 outdoor unit is open or short.120Compressor suction pipe temperature sensor of sub1 outdoor unit is open or…121Discharge pipe temperature sensor of sub1 constant compressor 1 is open or…View all 152 error codes
122Discharge pipe temperature sensor of sub1 constant compressor 2 is open or…123Temperature sensor of front-side heat exchanger (A) of sub1 outdoor unit is…124Temperature sensor of rear-side heat exchanger (B) of sub1 outdoor unit is open…125Liquid pipe temperature sensor of sub1 outdoor unit is open or short.126Subcooling inlet temperature sensor of sub1 outdoor unit is open or short.127Subcooling outlet temperature sensor of sub1 outdoor unit is open or short.128High pressure sensor of sub2 outdoor unit is open or short.129Low pressure sensor of sub2 outdoor unit is open or short.130Air temperature sensor of sub2 outdoor unit is open or short.132Compressor suction temperature sensor of sub2 outdoor unit is open or short.133Discharge pipe temperature sensor of sub2 constant compressor 1 is open or…134Discharge pipe temperature sensor of sub2 constant compressor 2 is open or…135Temperature sensor of front-side heat exchanger (A) of sub2 outdoor unit is…136Temperature sensor of rear-side heat exchanger (B) of sub2 outdoor unit is open…137Outdoor unit liquid pipe (condenser) temperature sensor of sub2 unit is open or…138Subcooling inlet temperature sensor of sub2 outdoor unit is open or short.139Subcooling outlet temperature sensor of sub2 outdoor unit is open or short.140High pressure switch of sub2 outdoor unit has tripped.141Reverse connection or missing phase of 3-phase power of sub2 outdoor unit.142Transmission error between sub2 and main outdoor units.143Excessive rise in high pressure of sub1 outdoor unit; compressor off due to…144Excessive drop in low pressure of sub1 outdoor unit; compressor off due to low…145Excessive rise in high pressure of sub2 outdoor unit; compressor off due to…146Excessive drop in low pressure of sub2 outdoor unit; compressor off due to low…147Low or high voltage of sub1 outdoor unit; input voltage out of range.148Voltage detection circuit of sub1 outdoor unit is out of order.149Low or high voltage of sub2 outdoor unit; input voltage out of range.150Voltage detection circuit of sub2 outdoor unit is out of order.151Function error of outdoor 4-way (reversing) valve in main or sub outdoor units…152Over-increase of discharge temperature of constant speed compressor 1 of sub3…153Over-increase of discharge temperature of constant speed compressor 2 of sub3…154High pressure switch of sub3 outdoor unit has tripped.155Reverse connection or missing phase of 3-phase power of sub3 outdoor unit.156Transmission error between sub3 and main outdoor units.157High pressure sensor of sub3 outdoor unit is open or short.158Low pressure sensor of sub3 outdoor unit is open or short.159Air temperature sensor of sub3 outdoor unit is open or short.161Compressor suction temperature sensor of sub3 outdoor unit is open or short.162Discharge pipe temperature sensor of sub3 constant compressor 1 is open or…163Discharge pipe temperature sensor of sub3 constant compressor 2 is open or…164Temperature sensor of front-side heat exchanger (A) of sub3 outdoor unit is…165Temperature sensor of rear-side heat exchanger (B) of sub3 outdoor unit is open…166Outdoor liquid pipe sensor of sub3 outdoor unit is open or short.167Subcooling inlet temperature sensor of sub3 outdoor unit is open or short.168Subcooling outlet temperature sensor of sub3 outdoor unit is open or short.169Excessive rise in high pressure of sub3 outdoor unit; compressor off due to…170Excessive drop in low pressure of sub3 outdoor unit; compressor off due to low…171Low or high voltage of sub3 outdoor unit; input voltage out of range.172Voltage detection circuit of sub3 outdoor unit is out of order.173Abnormal starting of main constant speed compressor; over-increase of…174Abnormal starting of sub1 constant speed compressor 1.175Abnormal starting of sub1 constant speed compressor 2.176Abnormal starting of sub2 constant speed compressor 1.177Abnormal starting of sub2 constant speed compressor 2.200Pipe detection error; number of indoor units detected differs from number…201Liquid pipe sensor of HR unit 1 is open or short.202Inlet sensor of subcooler of HR unit 1 is open or short.203Outlet sensor of subcooler of HR unit 1 is open or short.204Transmission error between HR unit 1 and outdoor unit; failing to receive HR…205Liquid pipe sensor of HR unit 2 is open or short.206Inlet sensor of subcooler of HR unit 2 is open or short.207Outlet sensor of subcooler of HR unit 2 is open or short.208Transmission error between HR unit 2 and outdoor unit.209Liquid pipe sensor of HR unit 3 is open or short.21DC peak / IPM fault or overcurrent to inverter compressor.210Inlet sensor of subcooler of HR unit 3 is open or short.211Outlet sensor of subcooler of HR unit 3 is open or short.212Transmission error between HR unit 3 and outdoor unit.213Liquid pipe sensor of HR unit 4 is open or short.214Inlet sensor of subcooler of HR unit 4 is open or short.215Outlet sensor of subcooler of HR unit 4 is open or short.216Transmission error between HR unit 4 and outdoor unit.217Liquid pipe sensor of HR unit 5 is open or short.218Inlet sensor of subcooler of HR unit 5 is open or short.219Outlet sensor of subcooler of HR unit 5 is open or short.22Overcurrent flows to inverter compressor; CT sensing circuit current exceeds…220Transmission error between HR unit 5 and outdoor unit.221Liquid pipe sensor of HR unit 6 is open or short.222Inlet sensor of subcooler of HR unit 6 is open or short.223Outlet sensor of subcooler of HR unit 6 is open or short.224Transmission error between HR unit 6 and outdoor unit.225Liquid pipe sensor of HR unit 7 is open or short.226Inlet sensor of subcooler of HR unit 7 is open or short.227Outlet sensor of subcooler of HR unit 7 is open or short.228Transmission error between HR unit 7 and outdoor unit.229Liquid pipe sensor of HR unit 8 is open or short.23DC voltage charging for inverter compressor driving is defective; DC charging…230Inlet sensor of subcooler of HR unit 8 is open or short.231Outlet sensor of subcooler of HR unit 8 is open or short.232Transmission error between HR unit 8 and outdoor unit.24High pressure switch of main outdoor unit has tripped; system off by high…240Central controller connector error (CNU connection failure); transmission…241Central controller data transmission error (sending error); CNU to central…242Central controller receive error; data length from CNU longer than protocol…243Central controller receive buffer overflow; excess data received.244Central controller to CNU data transmission failure; receive timeout exceeds 3…245Central controller send timeout; data sending failure from central controller…246Central controller receive timeout; data receiving failure of central…25Low or over voltage; input voltage is out of tolerable range.250Central controller checksum error; received checksum differs from calculated…251Central controller receive zero error; length of received data is 0.252Central controller wrong address error; setting address and actual address are…32Discharge temperature of inverter compressor at main outdoor unit is…33Discharge temperature of constant speed compressor at main outdoor unit is…34High pressure of main outdoor unit; system off by excessive increase of high…35Low pressure of main outdoor unit; system off by excessive decrease of low…40Low current at CT; R phase current drops below 2A during inverter compressor…41Discharge temperature sensor of inverter compressor is open or short.42Low pressure sensor of main outdoor unit is open or short.43High pressure sensor of main outdoor unit is open or short.44Air temperature sensor of main outdoor unit is open or short.45Temperature sensor of front-side heat exchanger of main outdoor unit is open or…46Suction temperature sensor of main outdoor unit is open or short.47Discharge temperature sensor of constant speed compressor of main outdoor unit…48Temperature sensor of rear-side heat exchanger of main outdoor unit is open or…51Excessive capacity of indoor units; sum of indoor unit capacity exceeds 130% of…52Transmission error from inverter PCB to main PCB; main controller cannot…53Transmission error from indoor unit to main PCB of outdoor unit; main PCB…54Reverse connection or missing phase of R, S, T power of main outdoor unit.57Transmission error from main PCB to inverter PCB; failing to receive main PCB…62Overheat of inverter heatsink.65Heat sink temperature sensor of inverter control PCB is open or short.
Service modes (9)
- Auto addressing for indoor unit["Turn on outdoor unit, HR unit, and indoor unit power.","Wait 3 minutes.","Press SW02M on the…
- Auto pipe detection["Turn No.1 of SW02M on HR unit PCB off.","Confirm No.2 and 3 of SW02M corresponds with number of…
- Data display mode (Sub unit)["Set sub unit DIP switch LED8=1, LED7=1 for data display mode."]
- Forced oil collecting operation["Set outdoor main PCB DIP switch SW03M with switches 1, 2, and 4 ON.","Press data button for 5…
- Forced operation (Cooling only model)["Press the forced operation button on the main unit of the indoor appliance."]
- Forced operation (Heat pump model)["Press the forced operation button on the main unit of the indoor appliance.","Indoor fan operates…
- Instant indoor unit checking mode["Set outdoor main PCB DIP switch SW03M
- Manual pipe detection["Enter central control address into each indoor unit using wired remote control.","Turn No.1 of…
- Test operation (Art Cool / Wall Mounted / Mirror indoor units)["After supplying power to the main body, press and hold the ON/OFF (forced operation) button for…
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