Troubleshooting Your LG Refrigerator’s Signals: A Comprehensive Guide to Error Codes
LG refrigerators are designed with sophisticated diagnostic systems that use error codes to signal potential issues. When a problem arises, these codes appear on the display, providing valuable clues to help you understand what’s going wrong. This guide will cover common error codes for a wide range of LG refrigerator models, including 3-door, 4-door, French door, InstaView Door-in-Door, side-by-side, and multi-door refrigerators with Smart ThinQ capabilities.

Important Safety Note: Before attempting any inspection or repair, always unplug your refrigerator to avoid the risk of electric shock. Exercise caution when working with appliance components.
How to Check Error Codes on LG Refrigerators
Error codes typically appear directly on the digital display panel of your refrigerator. The code is often preceded by “Er”. In some cases, the refrigerator’s Smart Diagnosis feature can also be used with the LG ThinQ app to identify issues and receive troubleshooting guidance.
Note: Once an issue is resolved, the corresponding error code should automatically clear from the display. If the code persists, the problem may not be fully resolved or there might be an underlying issue. Unplugging the refrigerator for a few minutes can sometimes reset the system and clear temporary error codes.
Fixing Error Codes On LG Refrigerators
Here is a breakdown of common LG refrigerator error codes, their meanings, potential causes, and suggested solutions:
Error Code | Description | Potential Causes | Suggested Solutions |
---|---|---|---|
Fan Errors | |||
E CF | Condenser Fan Error | Faulty harness connection, faulty condenser fan motor blade/motor, faulty main board | Check condenser fan wire harness connector and harness on the main board. Ensure fan rotates freely; remove obstacles. Verify condenser fan voltage. Check/replace main board. |
E FF | Freezer Fan Error | Faulty harness connection, faulty freezer fan motor blade/motor, faulty main board | Check freezer fan wire harness connector and harness on main board. Ensure fan rotates freely; remove obstacles. Verify freezer fan voltage. Check/replace main board. |
E rF | Refrigerator Fan Error | Faulty harness connection, faulty refrigerator fan motor blade/motor, faulty main board | Check refrigerator fan wire harness connector and harness on main board. Ensure fan rotates freely; remove obstacles. Verify refrigerator fan voltage. Check/replace main board. |
E IF | Ice Maker Fan Error | Faulty harness connection, faulty ice maker fan motor blade/motor, faulty main board | Check ice maker fan wire harness connector and harness on main board. Ensure fan rotates freely; remove obstacles. Verify ice maker fan voltage. Check/replace main board. |
Sensor Errors | |||
F dS | Defrost Sensor Error | Faulty wire harness, sensor connector disconnected (short/open circuit), faulty sensor, faulty main board | Check defrost sensor wire harness connector and connections on main board. Check defrost sensor resistance with a multimeter. Check main board. |
E FS | Freezer Sensor Error | Faulty wire harness, sensor connector disconnected (short/open circuit), faulty sensor, faulty main board | Check freezer sensor wire harness connector and connections on main board. Check freezer sensor resistance with a multimeter. Check main board. |
E rS | Refrigerator Sensor Error (Upper) | Faulty wire harness, sensor connector disconnected (short/open circuit), faulty sensor, faulty main board | Check sensor wire harness connector and connections on main board. Check refrigerator sensor resistance with a multimeter. Check main board. |
E r2 | Refrigerator Sensor 2 Error | Related to Refrigerator Sensor Error (E rS) | Refer to troubleshooting for E rS. |
E HS | Humidity Sensor Error | Faulty wire harness, sensor connector disconnected (short/open circuit), faulty sensor, faulty main board | Check humidity sensor wire harness connector and connections on main board. Check humidity sensor voltage with a multimeter. Check main board. |
E rt | Room Temperature Sensor Error | Faulty wire harness, sensor connector disconnected (short/open circuit), faulty sensor, faulty main board | Check sensor wire harness connector and connections on main board. Check room temperature sensor resistance with a multimeter. Check main board. |
E Id | Craft Ice Maker Sensor Error | Faulty wire harness, sensor connector disconnected (short/open circuit), faulty sensor, faulty main board | Check humidity wire harness connector and connections on main board. Check craft I/M sensor resistance with a multimeter. Check main board. |
E IS | Ice Maker Sensor Error | Faulty wire harness, sensor connector disconnected (short/open circuit), faulty sensor, faulty main board | Check humidity wire harness connector and connections on main board. Check I/M sensor resistance with a multimeter. Check main board. |
Communication Errors | |||
E CO | Communication Failure | Disconnection at boards or hinge, faulty harness connections, faulty main board, faulty user interface board | Check connections at user interface and main board. Check harness between user interface and main board. Check/replace UI board. Check/replace main board. |
E C1 | Dispenser Communication Error | Faulty harness connections, faulty dispenser board, faulty user interface board | Check connections on the display. Check harness between dispenser and user interface board. Check/replace dispenser board. Check/replace user interface board. |
Door and Drawer Errors | |||
E AS | Auto-door Switch Error | Faulty door switch (Reed Switch), faulty wire harness connector, faulty main board | Check wire harness on the main board. Check door Reed-switch using a multimeter and magnet. Check/replace mainboard if the error persists. |
L AS | Left Auto Drawer Switch Error | Related to Auto-door Switch Error (E AS) | Refer to troubleshooting for E AS, focusing on the left auto drawer. |
I LS | Smart Auto Drawer Switch Error | Related to Auto-door Switch Error (E AS) | Refer to troubleshooting for E AS, focusing on the smart auto drawer. |
r AS | Right Auto Drawer Switch Error | Related to Auto-door Switch Error (E AS) | Refer to troubleshooting for E AS, focusing on the right auto drawer. |
E dL | Left Auto Drawer Module Error | Faulty harness connection, faulty Hall sensor, faulty drawer motor, faulty module connection, faulty main board | Check module wire harness connector. Check Hall sensor (resistance and voltage). Check drawer motor and module. Check/replace main board. |
E dr | Right Auto Drawer Module Error | Related to Left Auto Drawer Module Error (E dL) | Refer to troubleshooting for E dL, focusing on the right auto drawer. |
E Ad | Auto Door Module Error | Related to Left Auto Drawer Module Error (E dL) | Refer to troubleshooting for E dL, focusing on the auto door module. |
I Ld | Auto Smart Drawer Module Error | Related to Left Auto Drawer Module Error (E dL) | Refer to troubleshooting for E dL, focusing on the auto smart drawer module. |
U Ld | Smart Auto-lift Module Error | Related to Left Auto Drawer Module Error (E dL) | Refer to troubleshooting for E dL, focusing on the smart auto-lift module. |
U LS | Smart Auto-lift Switch Error | Related to Auto-door Switch Error (E AS) | Refer to troubleshooting for E AS, focusing on the smart auto-lift switch. |
Defrost System Errors | |||
F dH | Defrost Heater Error | Faulty harness connection, faulty defrost heater thermal-fuse/heater, faulty main board | Check defrost heater wire harness connector. Check defrost heater and thermal-fuse resistance with a multimeter. Check/replace main board. |
Ice Maker Assembly Errors | |||
E IU | Craft Ice Maker Unit Error | Faulty Craft Ice maker stepper motor, Hall IC or heater, faulty wire harness connector, faulty main board, faulty display board | Check Craft Ice Maker Assembly components (Stepper Motor, Hall Sensor, Craft Sensor, Heater). Check main board. Check display board. |
E It | Ice Maker Unit error | Overloaded ice bin, disconnected ice maker unit, damaged motor or Hall IC, faulty main board, faulty user interface board | Check I/M motor wire harness connector and connections on main board. Check ice maker motor voltage with a multimeter. Check/replace user interface board. Check main board. |
Other Errors and Notifications | |||
OFF | Demo Mode notification | Appliance is in showroom/demo mode. | Deactivate demo mode (refer to your user manual for specific button combinations, often involves holding REFRIGERATOR and Express FRZ buttons). |
Sb | Sabbath Mode notification | Appliance is in Sabbath mode. | Deactivate Sabbath mode (refer to your user manual for specific button combinations, often involves holding SMART GRID and FREEZER buttons). Mode may turn off automatically after 96 hours. |
E CH | High Side Cycle leakage warning | Refrigerant leak on the high-pressure side (faulty 3-way valves, general leaks), abnormal temperature/compressor feedback | Avoid DIY repairs. Contact an LG technician due to safety and environmental concerns with refrigerant. |
E CL | Low Side Cycle leakage warning | Refrigerant leak on the low-pressure side. | Avoid DIY repairs. Contact an LG technician due to safety and environmental concerns with refrigerant. |
E FU | Failing Unit Error | Incorrect temperature, door not closing properly, insufficient cooling, faulty thermistor, faulty main board | Ensure appliance is on and cooling. Check freezer temp setting (-18°C). Minimize door open time. Ensure vents are not blocked. Check door seal. |
E gF | Flow meter sensor error | Closed water supply/kinked tube, faulty flow meter, sensor disconnection/short circuit, faulty main board, incorrect water pressure | Ensure water tap is open and tube is not kinked. Check water pressure. Check flow meter specifications/operation. |
E gS | Gas sensor error | Problem with gas sensing detection for PureNFresh ventilation system. | This relates to the ventilation system; consult your manual or LG support if this error persists. |
Hi | High Room Temperature | Ambient temperature exceeds +50°C. | Wait until the ambient temperature is within the refrigerator’s climate class specifications before operating. |
Lo | Low Room Temperature | Ambient temperature falls below -10°C. | Wait until the ambient temperature is within the refrigerator’s climate class specifications before operating. |
Electrical Characteristics of LG Refrigerator Sensors, Heater, and Fans
Component Type | Specific Component Name | Electrical Characteristic | Value | Measurement Conditions / Notes | Abnormal Value / Indication |
---|---|---|---|---|---|
Sensors | Defrost Sensor | Resistance | ~9800 Ω | At 25°C / 77°F | Short circuit or open circuit |
Freezer Sensor | Resistance | ~2300 Ω | At 25°C / 77°F | Short circuit or open circuit | |
Refrigerator Sensor (R1, Upper) | Resistance | ~9800 Ω | At 25°C / 77°F | Short circuit or open circuit | |
Humidity Sensor | Voltage | Varies | Check voltage using a multimeter. | Short circuit or open circuit | |
Room Temperature (Ambient) Sensor | Resistance | ~9800 Ω | At 25°C / 77°F | Short circuit or open circuit | |
Craft Ice Maker Sensor | Resistance | Varies | Check resistance using a multimeter. | Short circuit or open circuit | |
Ice Maker Sensor | Resistance | Varies | Check resistance using a multimeter. | Short circuit or open circuit | |
Hall sensor (Auto Drawer/Lift) | Resistance | ~17400 Ω (17.4 KΩ) | Between Black and Red wires. | ||
Hall sensor (Auto Drawer/Lift) | Voltage | +5 to 10 Vdc | Voltage received by the sensor. | If voltage is present but sensor fails, replace sensor. | |
Heater | Defrost Heater | Resistance | ~50 Ω | Check resistance using a multimeter. | OL (Open Line) or ∞ Ω (Infinite Resistance) |
Defrost Heater Thermal-Fuse | Resistance | 0.1 – 1.2 Ω | At 76°C / 169°F. Check resistance using a multimeter. | OL (Open Line) or ∞ Ω (Infinite Resistance) | |
Fans | Condenser Fan (4 wires) | Main voltage | ~12 Vdc | Test point: VCC “V” and GND “G”. | No voltage or incorrect voltage |
Condenser Fan (4 wires) | Feedback voltage | ~2.4 Vdc | Test point: GND “G” and FG “F”. Indicates if the fan motor is running. | No feedback signal | |
Condenser Fan (4 wires) | PWM voltage | 1.2 to 4.6 Vdc | Test point: PWM and GND “G”. Pulse Width Modulation signal controls fan speed. | Incorrect PWM signal | |
Condenser Fan (3 wires) | Main voltage | ~12 Vdc | Test point: VCC “V” and GND “G”. | No voltage or incorrect voltage | |
Condenser Fan (3 wires) | Feedback voltage | ~2.4 Vdc | Test point: GND “G” and FG “F”. Indicates if the fan motor is running. | No feedback signal | |
Freezer Fan (4 wires) | Main voltage | ~12 Vdc | Test point: VCC “V” and GND “G”. | No voltage or incorrect voltage | |
Freezer Fan (4 wires) | Feedback voltage | ~2.4 Vdc | Test point: GND “G” and FG “F”. Indicates if the fan motor is running. | No feedback signal | |
Freezer Fan (4 wires) | PWM voltage | 1.2 to 4.6 Vdc | Test point: PWM and GND “G”. Pulse Width Modulation signal controls fan speed. | Incorrect PWM signal | |
Freezer Fan (3 wires) | Main voltage | ~12 Vdc | Test point: VCC “V” and GND “G”. | No voltage or incorrect voltage | |
Freezer Fan (3 wires) | Feedback voltage | ~2.4 Vdc | Test point: GND “G” and FG “F”. Indicates if the fan motor is running. | No feedback signal | |
Refrigerator Fan (4 wires) | Main voltage | ~12 Vdc | Test point: VCC “V” and GND “G”. | No voltage or incorrect voltage | |
Refrigerator Fan (4 wires) | Feedback voltage | ~2.4 Vdc | Test point: GND “G” and FG “F”. Indicates if the fan motor is running. | No feedback signal | |
Refrigerator Fan (4 wires) | PWM voltage | 1.2 to 4.6 Vdc | Test point: PWM and GND “G”. Pulse Width Modulation signal controls fan speed. | Incorrect PWM signal | |
Refrigerator Fan (3 wires) | Main voltage | ~12 Vdc | Test point: VCC “V” and GND “G). | No voltage or incorrect voltage | |
Refrigerator Fan (3 wires) | Feedback voltage | ~2.4 Vdc | Test point: GND “G” and FG “F”. Indicates if the fan motor is running. | No feedback signal | |
Ice Maker Fan (4 wires) | Main voltage | ~12 Vdc | Test point: VCC “V” and GND “G). | No voltage or incorrect voltage | |
Ice Maker Fan (4 wires) | Feedback voltage | ~2.4 Vdc | Test point: GND “G” and FG “F”. Indicates if the fan motor is running. | No feedback signal | |
Ice Maker Fan (4 wires) | PWM voltage | 1.2 to 4.6 Vdc | Test point: PWM and GND “G”. Pulse Width Modulation signal controls fan speed. | Incorrect PWM signal |
Note: Always refer to your specific LG refrigerator model’s service manual for the most accurate and detailed specifications and troubleshooting procedures.
By understanding the meaning of these error codes, you can be better informed when troubleshooting issues with your LG refrigerator, potentially saving time and the cost of a service call.

I am a master Appliance Repair technician with over 35 years of experience in the field. I am passionate about helping people troubleshoot their appliances and fix common problems. My website, appliancemode.com, provides a wealth of information on troubleshooting common appliance issues and deciphering error codes. This website aims to empower people to tackle appliance repairs themselves and save money on service calls.