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Error code reference

LG Refrigerator Error Code Er RS2

Abnormal Refrigerator Sensor (2)

LG codesLG refrigerator codes

Abnormal Refrigerator Sensor (2) - cut or short circuit wire on the secondary (middle room) refrigerator temperature sensor.

First step from the service manual

Check for a loose connection in CON7 on main PCB.

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

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What Er RS2 means on a LG refrigerator

The Er RS2 error code on an LG refrigerator indicates an abnormal condition detected in the secondary refrigerator temperature sensor, also referred to as the middle room sensor. This sensor is responsible for monitoring temperature in a secondary zone within the refrigerator compartment, and the control board uses its readings to regulate cooling cycles accurately. When the main PCB detects a signal that falls outside the expected range, it logs this fault to alert the technician to a wiring or sensor problem in that circuit.

The two primary electrical faults that trigger Er RS2 are an open circuit (cut or broken wire) and a short circuit in the sensor wiring harness. An open circuit causes the sensor signal to drop out entirely, while a short circuit pulls the signal voltage to an abnormal level. In both cases, the main PCB cannot obtain a valid temperature reading from that sensor and flags the error. The first step in diagnosing this code is to inspect the connector at CON7 on the main PCB, as a loose or partially seated connector can mimic both fault types without any actual damage to the sensor or wiring.

If CON7 is secure and properly seated, the diagnostic focus shifts to the wiring harness running to the secondary sensor and the sensor itself. Technicians should check the harness for visible damage, pinching, or corrosion, and then measure sensor resistance to confirm whether the component is within specification. A failed sensor will require replacement, while damaged wiring can often be repaired by splicing or replacing the affected section of the harness.

Source: manufacturer service documentation.

Common causes of Er RS2

  1. 01

    Loose connector at CON7 on main PCB

    Wiring / connection

    A partially seated or loose connector at the CON7 port on the main circuit board is the first thing to check, as it can interrupt the sensor signal without any physical damage to the sensor or wiring. Reseat the connector firmly and clear the error to see if it returns.

  2. 02

    Broken or cut wire in sensor harness

    Part replacement

    A break in the wiring harness between the main PCB and the secondary refrigerator sensor will cause an open circuit, dropping the signal entirely and triggering Er RS2. Inspect the harness along its full length for any visible cuts, breaks, or areas where wiring may have been pinched.

  3. 03

    Short circuit in sensor wiring

    Part replacement

    If two conductors in the sensor harness make unintended contact, the resulting short pulls the signal to an abnormal voltage level that the PCB cannot interpret as a valid temperature. Look for damaged insulation, areas of chafing, or wiring routed too close to sharp metal edges.

  4. 04

    Failed secondary refrigerator temperature sensor

    Part replacement

    The sensor itself can fail internally, producing a resistance value that reads as either open or shorted to the PCB. If the wiring and connector check out, measure the sensor resistance and compare it to the expected specification. A reading that is open or near zero ohms confirms sensor failure.

  5. 05

    Corroded or damaged connector pins

    Wiring / connection

    Moisture intrusion into the CON7 connector or the sensor connector can cause pin corrosion that increases resistance to the point of triggering the fault, even if the connector appears seated. Inspect pins closely for oxidation, green or white deposits, or bent contacts.

See the test procedure for each cause

Frequently asked questions about Er RS2

What does Er RS2 mean on a LG refrigerator?
Er RS2 means the main control board has detected an abnormal signal from the secondary refrigerator temperature sensor, also called the middle room sensor. The fault is caused by either a cut wire, a short circuit, or a loose connection in the sensor circuit. The refrigerator cannot accurately monitor temperature in that zone until the fault is resolved. The first step is to check the connector at CON7 on the main PCB.
Can I fix Er RS2 myself, or do I need a technician?
Checking and reseating the CON7 connector on the main PCB is a straightforward task that a confident DIYer can perform after unplugging the refrigerator. If the connector is secure and the error persists, diagnosing a wiring short or open circuit and replacing the sensor requires basic electrical knowledge and a multimeter. If you are not comfortable working with wiring or circuit boards, a qualified appliance technician should handle the repair.
Is it safe to keep using my refrigerator when Er RS2 is displayed?
A failed secondary sensor can impair the refrigerator's ability to maintain accurate temperatures in the affected zone, which could result in food spoilage over time. The refrigerator may still run, but cooling performance may be unreliable. It is best to address the error promptly and monitor food temperatures closely in the meantime.
Will resetting my LG refrigerator clear the Er RS2 code?
A power reset may temporarily clear the error from the display, but the code will return if the underlying fault in the sensor circuit has not been corrected. Resetting without fixing the wiring or sensor issue does not resolve the problem. The reset is only useful for confirming whether a minor connection issue caused the fault after reseating the CON7 connector.
How much does it cost to repair an Er RS2 error on an LG refrigerator?
If only the wiring or connector needs attention, the repair cost is generally low, often just the cost of a service call ranging from $75 to $150. If the secondary temperature sensor requires replacement, parts typically cost between $20 and $60, with total repair costs including labor ranging from $100 to $250 depending on your location and the technician's rates. Repairing a damaged wiring harness falls somewhere in between depending on the extent of the damage.

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