LG split (3 indoor) LMU360CE

Aug 02, 2009

- I can understand you comment about the error code being displayed outside and the fans starting but no compressor. But error #2 relates to the inside connection to this unit to the sensor board. the compressor can't and wont start until you check the inside connection pipe to the board and see that the sensors are reading correcltly. The compressors start when the outside temperature is measured against the inside temp depending on the sensor board being able to read the data and being at a cetain voltage and temperature level

The manual clearly shows the error belonging to the INSIDE sensor boards, despite thefact that the fans work but the compressors will not engage until the INSIDE boards are reset or replaced so that they function correctly

The cause of error #2 is a short or internal circuit error on the INDOOR INLET PIPE

The sensors below should show this reading when checking the resistor voltage

Normal resistor : 5Kω/ at 25°C (Unplugged)
Normal voltage : 2.5Vdc / at 25°C (plugged)


So before you can fix it you have to ensure that these values exist. If not one of the other has to be replaced.

Unplug the sensor on Indoor unit PCB.
2. Estimate the resistance of each sensor
3. If the resistance of the sensor is 10Kω/5Kω at 25°C, then sensor is normal
4. If the resistance of the sensor is 0 Kω or ∞, then sensor is abnormal. ➔ Change the sensor.
5. Plug the sensor on Indoor unit PCB and Power ON.
6. Estimate the voltage of each sensor.
7. If the voltage of the sensor is 2.5Vdc / at 25°C, then sensor is normal.
8. If the resistance of the sensor is 0 or 5Vdc, then sensor is abnormal. ➔ Repair or Change the PCB