Samsung Air Conditioner Error Code E258

E258 indicates an open or short circuit fault in the discharge temperature sensor for fixed scroll compressor 3. The control board has detected a sensor signal voltage either above 4.95V (corresponding to approximately -30°C) or below 0.5V (corresponding to approximately 151°C), both of which fall outside the valid operating range. The unit restricts or stops operation to protect the compressor until the fault is resolved.

No. The E258 fault means the system cannot monitor the discharge temperature of fixed scroll compressor 3, removing a key protection against compressor overheating. Continuing to operate the unit without a valid sensor reading risks serious and potentially irreversible compressor damage. The system should be serviced before returning to normal operation.

A reset may temporarily clear the error code from the display, but the fault will return immediately if the underlying wiring or sensor problem has not been corrected. Because E258 is triggered by a measurable out-of-range voltage condition, the control board will re-detect it as soon as the system restarts and reads the sensor signal again. A permanent fix requires repairing or replacing the faulty component.

Some causes of E258, such as a loose connector or a visibly damaged wire, can be identified and addressed by a knowledgeable DIYer. However, working safely on a multi-compressor commercial or mini-split system requires familiarity with high-voltage circuits and refrigerant handling. If the sensor itself needs replacement or if the fault cannot be found at the wiring level, a qualified HVAC technician should perform the repair.

If only a wiring repair or connector cleaning is needed, labor costs may range from around $75 to $200 depending on access and time. If the discharge temperature sensor requires replacement, parts and labor combined typically range from $150 to $400. A control board replacement, if ultimately needed, can push total repair costs higher, often in the $400 to $900 range.