Model reference
LG LRNU09GSER0
Air Conditioner
1 document92 error codes7 service modes
Available documentation
Service Manual
- Air Conditioner Service Manual311 pg
MyPros+ Max
Diagnose your LG LRNU09GSER0.
- Step-by-step diagnostics from the service manual
- Test values, resistance specs, and wiring references
- Verified part numbers when replacement is needed
Start diagnosing
$29/month · Cancel anytime · Or $9.95 3-day pass
Error codes (92)
CodeMeaning
01Indoor unit room temperature sensor is open or short.02Indoor unit inlet pipe temperature sensor is open or short.03Indoor unit outlet pipe temperature sensor is open or short.04Drain pump malfunction; condensed water level rises and float switch detects…05Communication error between outdoor unit and indoor unit; indoor unit PCB fails…06Indoor unit outlet pipe temperature sensor is open or short.07Different operation mode between indoor unit and outdoor unit (all units must…09Indoor unit EEPROM error; serial number marked on EEPROM is 0 or FFFFFF.10Poor fan motor operation; fan motor connector disconnected or motor failure.100Excessive rise of discharge temperature of constant speed compressor 1 of sub1…101Excessive rise of discharge temperature of constant speed compressor 2 of sub1…102Excessive rise of discharge temperature of constant speed compressor 1 of sub2…103Excessive rise of discharge temperature of constant speed compressor 2 of sub2…104Communication error from sub1 outdoor unit to main outdoor unit; failing to…105Communication error from fan PCB to main PCB; failing to receive fan signal at…106Over-current of main outdoor fan motor (fan IPM fault).107Low voltage of fan motor driver.108Communication error from main PCB to fan PCB; failing to receive main signal at…109High pressure switch of sub1 outdoor unit operated by high pressure rising.11Communication error from indoor unit to main PCB of outdoor; outdoor unit…110Reverse connection or omitting connection of R, S, T power of sub1 outdoor unit.111Communication error from main outdoor unit to sub1 outdoor unit; failing to…113Liquid pipe temperature sensor of main outdoor unit is open or short.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.120Suction temperature sensor of sub1 outdoor unit is open or short.121Discharge temperature sensor of constant speed compressor 1 of sub1 outdoor…View all 92 error codes
122Discharge temperature sensor of constant speed compressor 2 of sub1 outdoor…123Temperature sensor of front-side heat exchanger of sub1 outdoor unit is open or…124Temperature sensor of rear-side heat exchanger of sub1 outdoor unit is open or…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.132Suction temperature sensor of sub2 outdoor unit is open or short.133Discharge temperature sensor of constant speed compressor 1 of sub2 outdoor…134Discharge temperature sensor of constant speed compressor 2 of sub2 outdoor…135Temperature sensor of front-side heat exchanger of sub2 outdoor unit is open or…136Temperature sensor of rear-side heat exchanger of sub2 outdoor unit is open or…137Liquid pipe temperature sensor of sub2 outdoor unit is open or short.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 operated by high pressure rising.141Reverse connection or omitting connection of R, S, T power of sub2 outdoor unit.142Communication error from main outdoor unit to sub2 outdoor unit; failing to…143Excessive rise in high pressure of sub1 outdoor unit; compressor off due to…144Excessive low pressure drop of sub1 outdoor unit; compressor off due to low…145Excessive rise in high pressure of sub2 outdoor unit; compressor off due to…146Excessive low pressure drop of sub2 outdoor unit; compressor off due to low…147Low or over voltage of sub1 outdoor unit; input voltage more than 487V or less…148Voltage detection circuit of sub1 outdoor unit is out of order.149Low or over voltage of sub2 outdoor unit; input voltage more than 487V or less…150Voltage detection circuit of sub2 outdoor unit is out of order.151Outdoor 4-way (reversing valve) switching error; pressure change does not occur…173Failure of main constant speed compressor operation (comp locking, check valve…174Failure of Sub1 constant speed compressor 1 operation (comp locking, check…175Failure of Sub1 constant speed compressor 2 operation (comp locking, check…176Failure of Sub2 constant speed compressor 1 operation (comp locking, check…177Failure of Sub2 constant speed compressor 2 operation (comp locking, check…178Failure of Sub3 constant speed compressor 1 operation (comp locking, check…179Failure of Sub3 constant speed compressor 2 operation (comp locking, check…21DC peak / IPM fault or overcurrent to inverter compressor.22Overcurrent of inverter compressor (MAX CT); current flowing at CT sensing…23Poor voltage charge for driving inverter compressor; DC charging not performed…24High pressure switch of main outdoor unit operated due to excessive high…25Low or over input voltage; input voltage is out of tolerable range (3 phase…32Excessive rise of inverter compressor discharge temperature; compressor off due…33Excessive rise of constant speed compressor discharge temperature; compressor…34Excessive rise in high pressure of main outdoor unit; compressor off due to…35Excessive low pressure drop of main outdoor unit; compressor off due to low…40Current sensor of inverter compressor is open or short.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 is open or short.46Suction temperature sensor of main outdoor unit is open or short.47Discharge temperature sensor of the constant speed compressor of main outdoor…48Temperature sensor of rear-side heat exchanger is open or short.49Voltage detection circuit of main outdoor unit is out of order.51Excessive capacity of indoor units connected; combined indoor unit spec exceeds…52Communication error from inverter PCB to main PCB; inverter PCB cannot receive…53Communication error from indoor unit to main PCB of outdoor; indoor cannot…54Reverse connection or omission of R, S, T power of main outdoor unit (wrong…57Communication error from main PCB to inverter PCB; main PCB cannot receive…62Overheat of inverter PCB heat sink; excessive rise of inverter heat sink…65Temperature sensor on the heat radiator panel of the inverter PCB is open or…
Service modes (7)
- Auto-Addressing1
- Backup Operation (Constant Speed Compressor)On the main outdoor unit, set DIP switch
- Data Display Mode (Outdoor Unit)1
- Forced Operation (Indoor Unit - Cooling Only Model)Press the forced operation (power) button on the indoor unit
- Forced Operation (Indoor Unit - Heat Pump Model)1. Press the forced operation button. 2. Indoor fan operates at low speed for about 15 seconds. 3…
- Instant Indoor Unit Checking Mode1. Set DIP switch
- Test Operation (Indoor Unit - Art Cool / Art Cool Wide)1
Full entry steps, exit procedures, and test sequences are available in Max.
Related LG air conditioner models
78,000+ service manuals · 160,000+ error codes · 55+ brands
Get Started$29/month · Cancel anytime · Or $9.95 3-day pass