Samsung Air Conditioner Error Code 258

Error 258 indicates a fault in the discharge temperature sensor circuit for fixed scroll compressor 3. The control board has detected a signal voltage either above 4.95V (open circuit, below -30C) or below 0.5V (short circuit, above 151C). Both conditions indicate an electrical fault in the sensor circuit rather than an actual extreme temperature reading. The system flags this error to prevent compressor damage from unmonitored discharge temperatures.

Yes, this error should be addressed promptly. The discharge temperature sensor protects compressor 3 from overheating by giving the control board real-time data about refrigerant conditions at the compressor outlet. If the sensor circuit is faulty, the system cannot reliably monitor this critical parameter, which could allow the compressor to operate under unsafe thermal conditions. The unit is right to limit or halt operation until the fault is cleared.

Repair costs vary depending on the root cause. If the issue is a loose or corroded connector that only requires cleaning and reseating, labor costs may be the primary expense, typically in the range of $75 to $150 for a service call. If the discharge temperature sensor itself needs replacement, parts and labor combined generally range from $150 to $350. If the PCB connector or board requires replacement, costs can be higher, often $300 to $600 or more depending on the unit and parts availability.

Some aspects of this repair are accessible to a knowledgeable DIYer. Checking the sensor wiring for visible damage, reseating the connector, and cleaning corroded terminals are straightforward tasks. However, if the sensor itself needs to be replaced or the fault is traced to the PCB, a qualified HVAC technician with the proper tools and refrigerant handling certification should complete the repair.

A power reset may temporarily clear the error code, but it will return if the underlying wiring or sensor fault is not repaired. Because the fault is hardware-based, the control board will detect the out-of-range voltage signal again as soon as the unit restarts and attempts to read the sensor. A reset alone is not a fix and should only be used as part of a diagnostic process.