LG Air Conditioner Error Code E458

E458 indicates a compressor excess current fault. The CT sensor detected a current value of 20 amps or more sustained for at least 3 seconds, which caused the control board to shut down the compressor as a protective measure. The fault can result from a genuine overcurrent condition in the compressor or from a faulty CT sensor reporting inaccurate values.

No. The E458 fault is a protective shutdown designed to prevent compressor motor damage or electrical failure. Continuing to operate the unit by bypassing or repeatedly resetting the fault without diagnosing the root cause risks burning out the compressor, which is one of the most expensive components in the system. The unit should remain off until the cause is identified and corrected.

Repair costs depend heavily on the root cause. Replacing a CT sensor is relatively inexpensive, typically in the range of $50 to $200 including labor. If the compressor itself has failed and needs replacement, costs can range from $600 to $2,000 or more depending on the unit size and model. A diagnostic service call to confirm the cause is the first step and usually runs $75 to $150.

Some basic checks, like inspecting the CT sensor connector for looseness or corrosion and reseating it, can be done by a knowledgeable DIYer. However, diagnosing whether the fault reflects a true compressor overcurrent condition requires a clamp meter to compare against the CT sensor reading, and addressing a failing compressor or refrigerant issue requires professional tools and certifications. A technician is recommended for anything beyond the initial connector inspection.

A power reset may temporarily clear the fault display, but if the underlying cause, whether a bad CT sensor or a failing compressor, has not been resolved, the error will return once the compressor restarts and the current threshold is exceeded again. Resetting without diagnosis is not a fix and can lead to more serious component damage.