mypros+
Error code reference

LG Refrigerator Error Code E 7

Cool Select Zone sensor open or short circuit (RSG5B* model display).

LG codesLG refrigerator codes

Cool Select Zone sensor open or short circuit (RSG5B* model display).

First step from the service manual

Check voltage between MAIN PCB CN51 #13 and #14; should be within 4.5V~1.0V.

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 E 7.

  • 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 E 7 means on a LG refrigerator

The E 7 error code on LG RSG5B* model refrigerators indicates a fault in the Cool Select Zone temperature sensor circuit. Specifically, the control system has detected either an open circuit or a short circuit in the sensor responsible for monitoring the temperature inside the Cool Select Zone compartment. This zone is a dedicated section of the refrigerator that allows users to set a specific temperature range independent of the main refrigerator cavity. Without accurate sensor feedback, the main PCB cannot regulate this compartment correctly, triggering the E 7 fault.

The primary diagnostic step involves checking the voltage at connector CN51 on the main PCB, specifically between pins 13 and 14. Under normal operating conditions, this voltage should fall within the range of 1.0V to 4.5V, which corresponds to the varying resistance output of the thermistor sensor across its operating temperature range. A reading at or near 0V typically points to a short circuit in the sensor or wiring harness, while a reading at or above 5V suggests an open circuit condition where continuity has been lost.

Common causes include a failed thermistor, damaged wiring between the sensor and the main PCB, or a corroded or loose connector at CN51. Physical damage from ice buildup in the Cool Select Zone area can crush or sever the sensor wiring. In less frequent cases, the main PCB itself may have a failed pull-up resistor or input circuit on the CN51 connector, though component-level board failure is a less likely cause compared to sensor or wiring issues.

Source: manufacturer service documentation.

Common causes of E 7

  1. 01

    Failed Cool Select Zone thermistor

    Part replacement

    The thermistor itself has failed internally, resulting in either no resistance (short) or infinite resistance (open). This is the most common cause and can be confirmed by disconnecting the sensor and measuring its resistance directly.

  2. 02

    Damaged or broken wiring harness

    Part replacement

    The wiring between the Cool Select Zone sensor and the main PCB connector CN51 can become pinched, cut, or broken, especially if ice has built up in the compartment area. Visually inspect the harness for kinks, cuts, or chafing along its entire length.

  3. 03

    Loose or corroded connector at CN51

    Wiring / connection

    A poor connection at pins 13 or 14 of the CN51 connector on the main PCB can cause intermittent or permanent signal loss. Inspect the connector for corrosion, bent pins, or a loose fit and reseat it firmly.

  4. 04

    Ice buildup causing sensor or wiring damage

    Wiring / connection

    Excessive ice formation in or around the Cool Select Zone can physically crush the sensor housing or its wiring. Defrosting the compartment fully before testing may reveal or resolve the issue.

  5. 05

    Main PCB input circuit failure

    Part replacement

    If the sensor and wiring test within normal parameters but the voltage at CN51 pins 13 and 14 is still out of the 1.0V to 4.5V range, the input circuit on the main PCB may be faulty. This is the least common cause and typically requires board replacement.

See the test procedure for each cause

Frequently asked questions about E 7

What does E 7 mean on a LG refrigerator?
The E 7 code on an LG RSG5B* refrigerator indicates that the Cool Select Zone temperature sensor has been detected as having an open or short circuit. The main PCB monitors the sensor signal at connector CN51 pins 13 and 14, where voltage should read between 1.0V and 4.5V during normal operation. When the voltage falls outside this range, the board flags the E 7 fault. The problem is most often in the sensor itself or the wiring connecting it to the board.
Can I fix the E 7 error on my LG refrigerator myself?
Some steps, like reseating the connector at CN51 or defrosting ice buildup around the Cool Select Zone, are accessible to a confident DIYer with basic tools. However, accurately diagnosing whether the fault lies in the sensor, wiring, or main PCB requires a multimeter and knowledge of how to safely access the board and connector. Replacing the thermistor sensor is a moderate difficulty repair, while replacing the main PCB is more involved and carries a higher parts cost.
Is it safe to keep using my refrigerator while the E 7 code is showing?
The main refrigerator and freezer compartments may continue to operate normally while the E 7 code is active, but the Cool Select Zone cannot be relied upon to hold its set temperature without a functioning sensor. Food stored specifically in the Cool Select Zone may not be kept at the correct temperature. It is best to relocate sensitive items to the main compartment and address the fault promptly.
Will resetting my LG refrigerator clear the E 7 error code?
A power reset may temporarily clear the E 7 display, but the code will return if the underlying sensor circuit fault is still present. The main PCB continuously monitors the sensor voltage at CN51, so any persistent open or short circuit condition will cause the error to reappear shortly after the unit restores power. A permanent fix requires repairing or replacing the faulty component.
How much does it cost to repair an E 7 error on an LG refrigerator?
Repair costs vary depending on the root cause. A replacement Cool Select Zone thermistor sensor is typically the least expensive fix, with parts generally ranging from $15 to $50. If the main PCB requires replacement, parts alone can range from $100 to $300 or more depending on availability. Adding professional labor, total repair costs commonly fall between $100 and $450, with board replacements at the higher end of that range.

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