LG Air Conditioner Error Code E387

E387 indicates a Hall IC connection error for the second outdoor fan motor (Fan2). The Hall IC is a sensor that monitors the fan motor's rotor position and speed. When the outdoor PCB loses the signal from this sensor, it triggers E387 and disables the fan circuit. The fault points to a wiring, connector, sensor, or PCB issue in the Fan2 Hall IC circuit.

It is not advisable to continue running the unit with an active E387 error. The system has flagged a fault in the Fan2 motor circuit, and operating without a properly functioning outdoor fan can cause the compressor to overheat. Continuing to run the unit in this condition risks more extensive and costly damage to the system.

A power reset may temporarily clear the E387 fault display, but if the underlying wiring or sensor problem is still present, the error will return once the unit attempts to run the outdoor Fan2 circuit again. A reset is useful for confirming whether the fault is intermittent, but it does not repair the root cause. The Hall IC wiring and connector should be inspected before assuming the issue is resolved.

Checking and reseating wiring connectors on the outdoor unit is within reach for a knowledgeable DIYer who is comfortable working with electrical components. However, accessing the outdoor unit's PCB and fan motor wiring requires removing panels and working near high-voltage components, so caution is essential. If the fault requires replacing the Hall IC sensor or the PCB, a licensed HVAC technician is strongly recommended.

Repair costs depend on what component is at fault. If the fix is simply reseating a connector, the cost may be limited to a service call fee, typically in the range of $75 to $150. Replacing a Hall IC sensor or wiring harness may bring the total to $150 to $400. A PCB replacement is the most expensive scenario, often ranging from $300 to $700 or more depending on parts availability and labor rates.