LG Air Conditioner Error Code 161

Error code 161 indicates that the compressor suction temperature sensor on the sub3 outdoor unit is reading as either open or shorted. The control board cannot obtain a valid temperature signal from this sensor. This fault causes the system to shut down the affected outdoor section to protect the compressor from operating under unknown refrigerant conditions.

You should not continue running the system with this error active on the sub3 outdoor unit. The suction temperature sensor protects the compressor from liquid refrigerant ingestion and overheating. Without a valid sensor reading, the control system cannot protect the compressor, and continued operation risks serious compressor damage.

If only the sensor connector needs reseating or cleaning, there may be no parts cost, though a service call fee typically ranges from $75 to $150. Replacing the suction temperature sensor itself generally costs between $20 and $80 for the part, plus labor. If the outdoor PCB needs replacement, total repair costs can range from $300 to $700 or more depending on the model and labor rates in your area.

A homeowner with basic electrical knowledge can safely check whether the sensor connector has come loose from the outdoor PCB, which is the most common cause. However, testing thermistor resistance, inspecting internal wiring, and replacing PCB components requires comfort with electrical diagnostics and work inside the outdoor unit. Any repairs involving refrigerant should only be performed by a certified technician.

A power reset may temporarily clear the error display, but if the sensor, wiring, or connector has an actual fault, the error code will return once the system restarts and re-checks the sensor circuit. The underlying fault must be diagnosed and repaired for the error to be permanently resolved.