LG refrigerator with error code E rS

As an expert technician, I have diagnosed the LG refrigerator with error code E rS. This specific error code indicates a communication failure or a malfunction within the Refrigerator Sensor (thermistor) circuit. This sensor is responsible for monitoring the temperature in the fresh food compartment; when the Main Control Board detects an open circuit or a short circuit in this path, it triggers the E rS display to prevent food spoilage or over-freezing.

LG refrigerator with error code E rS: Troubleshooting Instructions

1. Power Reset: Disconnect the refrigerator from the power outlet for 10 minutes. This can sometimes clear a temporary software glitch in the Main Control Board. If the code returns immediately upon plugging it back in, proceed to hardware testing.
2. Locate the Sensor: Open the refrigerator compartment. The Refrigerator Sensor is typically located behind a small, louvered plastic cover on the side wall or the back ceiling of the fresh food section.
3. Inspect Wiring: Remove the sensor cover and inspect the wire leads. Look for signs of corrosion, moisture, or broken wires. Ensure the connector is firmly seated.
4. Test Resistance: Disconnect the Refrigerator Sensor from its wire harness. Use a multimeter set to the Ohms (Ω) setting to measure the resistance across the sensor terminals.
5. Check the Main Control Board: If the sensor tests within the correct range, the issue may lie in the wiring harness between the sensor and the board, or the Main Control Board itself. Access the board (usually located on the back of the unit) and check the CON6 or P1 connector (depending on your specific model) for secure seating.

Expected Ohmic/Resistance Values

The Refrigerator Sensor is an NTC (Negative Temperature Coefficient) thermistor, meaning its resistance increases as the temperature decreases.

• At Room Temperature (approx. 77°F / 25°C): 8k Ω – 12k Ω
• At Refrigerator Temperature (approx. 37°F / 3°C): 25k Ω – 30k Ω
• At Freezing Point (32°F / 0°C): 30k Ω – 35k Ω

If the multimeter reads 0 Ω (shorted) or OL (open circuit), the Refrigerator Sensor is defective and must be replaced.

Estimated Repair Cost

• Refrigerator Sensor (Thermistor): $15 – $45 USD.
• Main Control Board (if the sensor is functional but the error persists): $120 – $260 USD.

Safety Warnings

Warning: Always disconnect the refrigerator from the power source before removing any panels or touching electrical components. Failure to do so can result in severe electrical shock. If you are testing live voltage at the Main Control Board, use extreme caution and ensure your multimeter probes are properly insulated.

Repair Difficulty

Difficulty: DIY (Easy to Moderate)
Replacing the Refrigerator Sensor is a straightforward task that most homeowners can complete with a screwdriver and a multimeter. However, if the issue is traced back to a faulty Main Control Board, the repair becomes moderate in difficulty due to the complexity of the wiring harnesses.