LG Air Conditioner Error Code E301

E301 means the control board has detected that the high pressure sensor is detached or not communicating properly. The high pressure sensor monitors refrigerant pressure on the discharge side of the compressor. When the board receives no valid signal from this sensor, it shuts the unit down to prevent compressor damage and displays E301.

No, you should not attempt to operate the unit while E301 is active. The high pressure sensor is a safety device that protects the compressor from damage caused by excessive refrigerant pressure. Running the system without a functioning pressure sensor removes that protection and can lead to compressor failure or other serious damage.

Costs vary depending on the root cause. If only a connector needs to be reseated, a service call fee of roughly $75 to $150 may be the only expense. Replacing a high pressure sensor typically adds $50 to $150 in parts cost. If the control board is at fault, board replacement can range from $150 to $400 or more depending on the model, plus labor.

If the cause is simply a disconnected wiring harness connector, reconnecting it is a straightforward task for a handy homeowner after powering down the unit. However, if the sensor itself or the wiring harness is damaged, those repairs require more technical skill and, in the case of refrigerant handling, may require a certified technician. Always disconnect power before inspecting any internal components.

A simple power reset will not permanently clear E301 if the underlying issue has not been resolved. The error will return as soon as the control board checks the sensor signal and again finds it missing or invalid. The sensor connection or the sensor itself must be repaired or replaced before the code will clear and stay clear.