LG Air Conditioner Error Code E378

E378 indicates an overcurrent fault in the outdoor unit's second fan motor (Fan2). The outdoor control board detected that Fan2 was drawing more current than its rated operating range allows. The system shuts down to prevent damage to the motor, wiring, or control board. The fault must be diagnosed and corrected before normal operation resumes.

No, you should not continue operating the unit while E378 is active. An overcurrent condition in the fan motor circuit can cause wiring insulation to overheat, damage the control board, or permanently burn out the Fan2 motor. The unit's protection circuit will typically prevent operation anyway, but bypassing or repeatedly resetting without repair increases the risk of more extensive damage.

A power reset may temporarily clear the E378 fault and allow the unit to restart, but if the underlying cause such as a failing motor, bad capacitor, or wiring fault is not corrected, the error will return during operation. Repeated overcurrent events without repair can cause progressive damage to the fan motor and control board. A reset should only be used as part of the diagnostic process, not as a permanent fix.

Some causes, such as clearing a debris obstruction from the outdoor fan, can be handled safely by a homeowner after disconnecting power to the unit. However, testing motor windings, inspecting capacitors, and diagnosing wiring faults require electrical knowledge and proper tools. Motor replacement and control board work should be performed by a qualified technician due to the voltages and components involved.

Repair costs depend on the root cause. Clearing a debris obstruction is essentially free if you do it yourself. A replacement run capacitor typically costs between $20 and $60 in parts, while a new outdoor fan motor can range from $80 to $250 or more depending on the model. Adding labor from a technician, total repair costs can range from $100 to $500 or higher if the control board also requires replacement.