Current Sensor Error / Outdoor Fan Motor Anomaly

What does U8 (00) mean?

This code indicates either an abnormal current detection by the current sensor (-1.5A to 1.5A) during compressor operation, or an abnormal rotational frequency of the outdoor fan motor. Fan motor abnormality occurs if rotation is below 100 rpm for 1 second at >=20°C ambient temperature, or below 80 rpm / above 1300 rpm continuously for 1 minute. Potential root causes include incorrect compressor wiring, a defective current sensor circuit on the outdoor power circuit board, DC fan motor failure, or an issue with the outdoor circuit controller board.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Check the voltage of the outdoor circuit controller board during operation.

2. 4

   Replace the outdoor power circuit board if the current sensor issue persists after verifying wiring.

3. 5

   Replace the outdoor circuit controller board if the fan motor failure persists after checking/replacing the motor.