LG window air conditioner

Unplug the air conditioner and check the wire harness connections on the electronic control board. Examine the electronic control board for damage. Check for a pinched or broken wire in the temperature sensor wire harness. Replace the temperature sensor if it's defective.

Unplug the air conditioner and check the wire harness connections on the electronic control board. Examine the electronic control board for damage. Check for a pinched or broken wire in the indoor temperature sensor wire harness. Replace the indoor temperature sensor if it's defective.

Unplug the air conditioner and check the wire harness connections on the electronic control board. Examine the electronic control board for damage. Check for a pinched or broken wire in the indoor temperature sensor wire harness. Replace the indoor temperature sensor if it's defective.

Clean or replace filters if dirty. Unplug the window air conditioner and check all components for visible damage. Check fan blades for damage or obstructions and replace any damaged fan blades. Check all wire harness connections. Replace any damaged wire harnesses.

After the air conditioner exits defrost mode and resumes normal operation, check the unit to see if it's cooling properly. If so, then the E4 code is normal. If the portable air conditioner frequently goes into the defrost mode and isn't cooling properly, check the air filters and clean or replace filters if dirty.

Empty the water collection tank. If the P2 or FL code appears when the tank is empty, replace the float switch or sensor in the collection tank.