mypros+
Error code reference

LG Refrigerator Error Code 1E

FZ-Sensor Error

LG codesLG refrigerator codes

FZ-Sensor Error — sensor housing separation, contact error, disconnection, or short circuit; detected temperature above 149°F (+65°C) or below -58°F (-50°C).

First step from the service manual

Measure voltage between Main PCB CN30-4 and CN76-1; should read between 4.5V and 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 1E.

  • 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 1E means on a LG refrigerator

The 1E error code on an LG refrigerator indicates a freezer compartment temperature sensor (FZ-Sensor) fault. This sensor is a thermistor that continuously reports the internal freezer temperature to the main PCB. When the control board detects a reading outside the acceptable operating range, specifically above 149°F (65°C) or below -58°F (-50°C), it interprets that signal as a sensor fault and triggers the 1E code. These out-of-range readings typically point to an open or shorted thermistor rather than an actual temperature extreme inside the freezer.

The fault can originate from several physical conditions along the sensor circuit: the sensor housing may have separated from its mounting point, the connector pins may have lost proper contact at the harness junction, the wiring between the sensor and main PCB may be broken or corroded, or the thermistor itself may have failed internally with a short circuit. The primary diagnostic checkpoint involves measuring voltage at Main PCB connector CN30 pin 4 and connector CN76 pin 1. A healthy sensor circuit produces a voltage reading between 1.0V and 4.5V depending on the actual freezer temperature. A reading outside this window confirms a circuit fault rather than a refrigeration problem.

Because this code reflects an electrical signal issue rather than a cooling failure, the freezer may still be operating normally in the short term. However, with no valid temperature feedback, the control board cannot regulate the compressor and fans correctly, which can lead to overcooling, undercooling, or compressor damage over time. Prompt diagnosis and repair of the sensor circuit is important to prevent secondary damage to perishables and refrigeration components.

Source: manufacturer service documentation.

Common causes of 1E

  1. 01

    Failed freezer thermistor

    Part replacement

    The thermistor itself has failed internally, either open or shorted, producing a resistance value outside the normal operating range. This results in a voltage reading at the main PCB outside the 1.0V to 4.5V window and is the most frequent cause of this code.

  2. 02

    Loose or disconnected wiring connector

    Wiring / connection

    The connector linking the FZ-Sensor harness to the main PCB at CN30-4 or CN76-1 may have vibrated loose or pulled apart, interrupting the signal circuit. Inspect both connector bodies for secure seating and check the pins for corrosion or spread contacts.

  3. 03

    Sensor housing separation from mounting point

    Wiring / connection

    The sensor housing can physically separate from its clip or bracket inside the freezer compartment, causing it to be exposed to temperature extremes it was not designed to measure in that position. Visually inspect the sensor to confirm it is seated correctly in its housing and mounting location.

  4. 04

    Damaged or broken wiring harness

    Part replacement

    The wiring between the freezer sensor and the main PCB can develop breaks or shorts due to repeated door movements, ice buildup pressing against the wire, or rodent damage. Continuity testing along the harness length will identify any open or shorted segments.

  5. 05

    Main PCB fault

    Part replacement

    If the sensor, connectors, and wiring all test correctly, the main PCB may have a failed input circuit at CN30-4 or CN76-1 that is misreading a valid sensor signal. This is the least common cause and should only be considered after all wiring and sensor components have been confirmed good.

See the test procedure for each cause

Frequently asked questions about 1E

What does 1E mean on a LG refrigerator?
The 1E code indicates a freezer temperature sensor (FZ-Sensor) error. The main PCB has detected a signal from the freezer thermistor that falls outside the valid operating range, either above 149°F (65°C) or below -58°F (-50°C). This points to a sensor failure, a wiring disconnection, a contact issue at a connector, or a short circuit in the sensor circuit rather than an actual temperature extreme inside the freezer.
Can I fix the 1E error on my LG refrigerator myself?
A knowledgeable DIYer can attempt to diagnose this code by visually inspecting the freezer sensor housing, checking connectors at the main PCB (CN30-4 and CN76-1), and measuring voltage at those terminals with a multimeter. If the voltage reads outside the 1.0V to 4.5V range and the connectors look secure, replacing the freezer thermistor is a straightforward repair that requires basic tools and the correct replacement part. If the wiring harness is damaged or the main PCB is suspected, professional repair is advisable.
Is it safe to use my refrigerator while the 1E code is showing?
Short-term use may be possible if the freezer still feels cold, but it is not advisable to rely on the refrigerator for extended periods with this fault active. Without valid temperature feedback, the control board cannot regulate cooling cycles accurately, which could lead to food spoilage or damage to compressor components. Check freezer contents and move temperature-sensitive items if the repair cannot be completed quickly.
How much does it cost to repair a 1E error on an LG refrigerator?
If the issue is limited to the freezer thermistor, the part typically costs between $10 and $40, and a technician labor charge would bring the total to roughly $100 to $200 depending on your area. A damaged wiring harness repair or connector replacement may fall in a similar range. If the main PCB needs replacement, costs can rise to $200 to $500 or more including parts and labor. Getting a diagnosis first helps narrow down which component is actually at fault.
Will resetting my LG refrigerator clear the 1E error code?
A reset, typically performed by unplugging the refrigerator for several minutes, may temporarily clear the code from the display. However, if the underlying cause, such as a failed thermistor, broken wire, or loose connector, has not been corrected, the 1E code will return once the control board runs its sensor checks again. A reset is useful for confirming whether the fault is intermittent, but it is not a repair.

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