LG Air Conditioner Error Code C2

The C2 code on an LG air conditioner indicates that the outdoor temperature sensor (thermistor) has been detected as either shorted or open circuit. The outdoor PCB continuously monitors this sensor to regulate system operation, and when the signal falls outside acceptable parameters, it triggers the C2 fault and halts operation. The sensor should measure approximately 10 kilohms at 25 degrees Celsius when functioning correctly.

The unit will generally shut itself down when a C2 error is active, which is a protective response. Attempting to bypass or reset the error repeatedly without addressing the underlying sensor fault is not recommended. Operating the system without accurate outdoor temperature data can lead to improper compressor control and potential damage over time.

Repair costs vary depending on what needs to be replaced. If only the thermistor sensor itself has failed, parts are generally inexpensive, and the total repair including labor typically falls in the range of $75 to $200. If the outdoor PCB assembly requires replacement, costs can range from $200 to $600 or more depending on the unit model and labor rates in your area.

A homeowner can check whether the sensor connector at the outdoor PCB has come loose and reseat it if needed. However, testing the thermistor resistance requires a multimeter and some familiarity with the outdoor unit's components. If the sensor itself has failed or the wiring harness is damaged, replacing those components typically requires a qualified technician to handle safely.

A power reset may temporarily clear the C2 code, but if the thermistor or its wiring is actually faulty, the error will return once the system restarts and the PCB re-evaluates the sensor signal. A reset is useful as a first step to rule out a transient fault, but a recurring C2 code requires proper diagnosis and repair of the sensor circuit.