LG Refrigerator Error Code EXT-SENSOR

EXT-SENSOR indicates a fault in the external or ambient temperature sensor circuit. The error appears when the sensor reports a temperature outside the valid range of -58°F to 122°F, which tells the control board the circuit is not functioning correctly. Possible causes include a broken wire, short-circuit, bad connector contact, or a missing sensor housing.

A power reset may temporarily clear the error code from the display, but it will return if the underlying sensor circuit fault is not repaired. The main PCB continuously monitors the sensor voltage at CN 10, so any persistent wiring issue, short, or failed sensor will trigger the code again after the reset.

Repair costs depend on the root cause. If only a wiring repair or connector reseating is needed, the cost may be minimal, primarily your time or a small labor charge. If the external temperature sensor itself needs replacement, parts typically range from $15 to $50 depending on the specific model. If the main PCB is involved, costs can rise to $150 to $400 or more including parts and professional labor.

Some causes of this error are DIY-friendly. Start by unplugging the refrigerator and visually inspecting the sensor wiring harness and connectors for obvious damage or loose connections. If you have a multimeter, check the voltage at main PCB connector CN 10 between pins 8 and 7 to see if it falls within the 1.0V to 4.5V normal range. If the wiring is intact and the sensor itself has failed, replacing the sensor is a moderate-difficulty repair that many experienced DIYers can complete.

The refrigerator may continue to run with this error active, but its ability to optimize cooling based on room conditions will be compromised. For short periods this is generally not dangerous, but prolonged operation without a functioning ambient sensor can reduce efficiency and potentially affect cooling performance. It is best to diagnose and repair the fault promptly to avoid food safety concerns.