LG Air Conditioner Error Code 168

Error code 168 on an LG air conditioner indicates that the subcooling outlet temperature sensor on the sub3 outdoor unit has been detected as open or shorted. This sensor is part of the refrigeration circuit and monitors refrigerant temperature after the subcooling stage. The fault can be caused by a disconnected connector, a failed sensor, or damaged wiring. The system flags this code to alert a technician and may restrict operation to avoid system damage.

Continuing to run the system with error code 168 active is not recommended. The subcooling outlet sensor provides data the controller uses to manage refrigerant flow and protect the compressor. Operating without accurate sensor feedback could lead to inefficient performance or, in some cases, compressor damage over time. It is best to address the fault before resuming normal operation.

Resetting the unit may temporarily clear the error code, but it will return if the underlying sensor fault is still present. The controller continuously monitors the sensor signal, so any open or short condition will trigger the code again shortly after restart. A reset is only useful for confirming whether the fault is intermittent. A proper repair of the sensor, connector, or wiring is required for a permanent resolution.

A knowledgeable DIYer can start by checking that the temperature sensor connector on the sub3 outdoor unit is properly seated and undamaged. If the connector looks secure, diagnosing the sensor requires a multimeter to check resistance values, which is within reach of experienced DIYers. However, replacing components in a multi-split or VRF outdoor unit and handling refrigerant circuits should be left to a certified HVAC technician.

If the fix is simply reseating a loose connector, there may be little to no parts cost, though a technician diagnostic visit typically runs between $75 and $150. If the NTC thermistor sensor needs replacement, parts and labor combined could range from $150 to $400 depending on the unit configuration and local labor rates. A control board replacement, if required, would be at the higher end of the cost range.