mypros+
Error code reference

LG Refrigerator Error Code Er rS

Refrigerator sensor (R1-sensor) abnormal

LG codesLG refrigerator codes

Refrigerator sensor (R1-sensor) abnormal - short circuit or open circuit in the upper refrigerator compartment sensor.

First step from the service manual

Check for short circuit in the refrigerator sensor R1.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

MyPros+ Max

Get the full diagnostic procedure for Er rS.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What Er rS means on a LG refrigerator

Er rS is a refrigerator compartment sensor fault detected by the main control board. The board monitors resistance values from the refrigerator sensor (also called the fridge thermistor) continuously. When it detects a short circuit or an open circuit caused by a disconnected or broken sensor, it logs this code and may disable normal temperature regulation for the refrigerator section. The sensor is typically mounted inside the fresh food compartment and sends temperature data to the control board via a wiring harness.

For homeowners, this error means the refrigerator's brain has lost communication with the temperature sensor inside the fridge section. Without accurate temperature readings, the refrigerator cannot properly control cooling, which puts food at risk. The issue is either a wiring problem between the sensor and control board, or the sensor itself has failed electrically.

This code does not affect the freezer sensor circuit, which is a separate component. However, since the refrigerator compartment temperature can no longer be reliably managed, food spoilage is a real concern if the error is not addressed promptly.

Source: manufacturer service documentation.

Common causes of Er rS

  1. 01

    Disconnected refrigerator sensor wiring harness

    Wiring / connection

    The connector linking the refrigerator thermistor to the main wiring harness may have come loose, especially after a service visit or from vibration over time. A disconnected harness causes an open circuit, which the control board reads as Er rS.

  2. 02

    Damaged or broken sensor wiring

    Part replacement

    The wiring between the refrigerator sensor and the control board can develop breaks or shorts due to pinching, wear, or ice buildup pressing against the wire. A short or break in the wire produces the same signal the control board interprets as a sensor fault.

  3. 03

    Failed refrigerator thermistor (sensor)

    Part replacement

    The thermistor itself can fail internally, producing resistance values outside the expected range or no signal at all. A shorted or open thermistor will trigger Er rS even if the wiring is intact.

  4. 04

    Faulty main control board

    Part replacement

    If the wiring and sensor both test within specification, the main control board may have a failed input circuit for the refrigerator sensor. This is the least common cause but can occur when the board has suffered a power surge or component failure.

See the test procedure for each cause

Frequently asked questions about Er rS

What does Er rS mean on an LG refrigerator?
Er rS means the main control board has detected a fault with the refrigerator compartment temperature sensor. The board found either a short circuit or a disconnection in the sensor circuit. This prevents accurate temperature monitoring in the fresh food section and requires diagnosis of the sensor and its wiring harness.
How do I fix Er rS on an LG refrigerator?
Start by unplugging the refrigerator and locating the refrigerator sensor wiring connector, typically found at the back wall of the fresh food compartment or near the control board housing. Check that the connector is fully seated and that no wires are visibly pinched or broken. If the wiring looks intact, test the thermistor with a multimeter for correct resistance at room temperature (most LG fridge thermistors read approximately 5,000 ohms at 77 degrees F). Replace the sensor if it reads open or shorted.
Can I still use my LG refrigerator when it shows Er rS?
The refrigerator may continue running with Er rS active, but the control board cannot accurately regulate the temperature in the fresh food compartment without a working sensor. This means the fridge section could run too warm or too cold. Do not store perishable food or medications in the refrigerator section until the sensor fault is resolved, as temperatures may be unpredictable.
How much does it cost to fix Er rS on an LG refrigerator?
If the fix is a reconnected wiring harness, the cost is nothing beyond your time. An LG refrigerator thermistor typically costs between 10 and 40 dollars as a replacement part. If professional service is needed, expect a labor charge of 80 to 150 dollars on top of parts. A control board replacement, the least likely fix, can cost 150 to 300 dollars for the part alone, making professional diagnosis worthwhile before replacing it.
How do I test the refrigerator sensor to confirm it is causing Er rS?
Disconnect the refrigerator sensor connector from the wiring harness and measure resistance across the sensor terminals with a multimeter set to ohms. At room temperature, a working LG refrigerator thermistor should read around 5,000 ohms. A reading of zero (short) or infinite resistance (open circuit) confirms the sensor has failed and needs replacement. If the sensor reads correctly, inspect the wiring harness between the sensor and control board for damage before replacing any parts.

Related LG refrigerator codes

All LG refrigerator codes
View all 485 LG refrigerator codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass