LG Freezer Error Code 1

Error code 1 on an LG freezer signals a problem with the freezer temperature sensor (F-SENSOR). The control board has detected a signal outside the valid range, corresponding to a temperature reading above +50°C or below -50°C, which indicates the sensor circuit is open or shorted. The sensor, its wiring, or the connector at MAIN PCB CN30 is the most likely source of the fault.

Continued use is not recommended when error code 1 is active. Without a functioning temperature sensor, the control board cannot accurately regulate the freezer compartment temperature, which could result in food not being kept at a safe temperature. The freezer may over-cool or fail to maintain adequate cooling depending on how the control system responds to the fault.

A power reset may temporarily clear the error code display, but if the underlying sensor circuit fault is still present, the code will return once the control board completes its diagnostic cycle. Error code 1 reflects an active hardware fault, not a software or communication glitch, so a lasting fix requires identifying and repairing the failed sensor, wiring, or connector.

A knowledgeable DIYer can perform the initial diagnostics by checking the voltage at MAIN PCB connector CN30 between pins 4 and 8, which should read between 1.0V and 4.5V under normal conditions. Inspecting and reseating the connector or replacing the F-SENSOR are tasks within reach if you are comfortable with basic appliance repair. If the wiring harness needs repair or the MAIN PCB needs replacement, professional service is recommended.

If only the F-SENSOR thermistor needs replacement, parts typically cost in the range of $15 to $50 depending on the model, with professional labor adding $80 to $150 in most markets. If the wiring harness requires repair or replacement, costs can rise to the $100 to $250 range including labor. A MAIN PCB replacement is the most expensive scenario, potentially totaling $200 to $450 or more with installation.