LG Air Conditioner Error Code 117

Error code 117 means the low pressure sensor on the sub1 outdoor unit is reading as open or shorted. This indicates the sensor circuit is broken or the sensor has failed, preventing the system from monitoring low-side refrigerant pressure. The control board triggers this code to alert the technician and protect the compressor from operating under unknown pressure conditions.

It is not recommended to continue operating the unit while error code 117 is active. Without a valid low pressure signal, the system cannot properly protect the compressor from low refrigerant or other pressure-related conditions. Continued operation risks compressor damage, which is significantly more expensive to repair than the sensor or wiring.

If only the lead wire or connector needs repair or replacement, costs are typically in the range of $75 to $200 including labor. Replacing the low pressure sensor itself usually falls in the range of $150 to $350 depending on parts and labor rates in your area. If the outdoor unit control board is at fault, repair costs can range from $300 to $600 or more.

Some basic checks are accessible to a knowledgeable DIYer, such as inspecting the pressure sensor connector and lead wire for obvious damage or disconnection. However, testing the sensor's electrical output and working around refrigerant components requires proper tools and training. If the wiring appears intact, further diagnosis and any refrigerant-related work should be handled by a certified HVAC technician.

A power reset may temporarily clear the error code, but if the underlying fault in the sensor or wiring still exists, the code will return once the system restarts and attempts to read the sensor. A reset alone does not fix the problem and should not be relied upon as a solution.