LG Refrigerator Error Code Ambient Air Sensor Error

This error means the main control board has detected a problem with the external ambient air temperature sensor circuit. The sensor monitors room temperature to help regulate cooling performance. The board checks for a voltage signal between 1.0V and 4.5V at connector CN31, and when that signal is outside this range, the error is triggered. The root cause is typically a failed sensor, damaged wiring, or a loose connector.

The refrigerator may continue to run with this error active, but its ability to optimize cooling based on room temperature will be compromised. This could lead to reduced efficiency or inconsistent temperatures over time. It is best to diagnose and resolve the fault promptly to avoid potential food safety concerns from improper cooling.

A power reset may temporarily clear the error code, but if the underlying fault in the sensor circuit remains, the error will return once the control board runs its diagnostics again. Resetting is useful for confirming whether the fault is intermittent, but it is not a permanent solution. The voltage at CN31 should be measured and the sensor or wiring should be inspected to resolve the issue properly.

A knowledgeable DIYer can attempt this repair by first inspecting the wiring harness and connector at CN31 for obvious damage or looseness. Using a multimeter to check the voltage at CN31 pins 1 through 4 will help pinpoint whether the sensor, wiring, or control board is at fault. Replacing the ambient air thermistor is a relatively straightforward repair if the sensor is confirmed faulty. However, if the main PCB needs replacement, professional service is recommended.

If only the ambient air thermistor needs replacement, parts typically cost in the range of $15 to $50 depending on the specific model. If a service technician is required, labor costs can add $80 to $150 or more to the total. Main PCB replacement, if needed, is significantly more expensive, with parts alone ranging from $150 to $350 or higher.