LG Air Conditioner Error Code 163

Error code 163 indicates that the discharge temperature sensor on constant speed compressor 2 of the sub3 outdoor unit has been detected as open or shorted. This sensor measures the refrigerant discharge temperature leaving the compressor. The system flags this code when the sensor signal falls outside the acceptable resistance range, pointing to a wiring, connector, or sensor component fault.

Running the system with this fault active is not recommended. The discharge temperature sensor protects compressor 2 from overheating by giving the control board real-time temperature data. Without a reliable sensor signal, the PCB cannot properly protect that compressor, which could lead to compressor damage if the unit continues to operate under this fault condition.

Repair costs depend on what component has failed. A replacement discharge temperature sensor is typically a low-cost part, with labor for diagnosis and replacement bringing the total to a range of roughly $100 to $300 in many cases. If the outdoor unit PCB has failed and requires replacement, costs can range significantly higher, from $300 to $700 or more depending on the unit model and local labor rates.

The first step, checking that the sensor connector is properly seated at the PCB, can be done by a careful DIYer comfortable working inside an outdoor unit with power disconnected. However, accurately testing thermistor resistance, tracing wiring faults through a multi-zone outdoor unit, and replacing PCB components generally requires a qualified HVAC technician with the proper tools and knowledge of refrigerant systems.

A power reset may temporarily clear the error display, but the code will return if the underlying sensor, wiring, or connector fault has not been corrected. A reset is only useful as a diagnostic step to confirm the fault is persistent and not a one-time communication glitch. The physical cause must be identified and repaired to resolve the error permanently.