The IE error means inlet error — water didn't reach required level within the time limit.
The LG front-load washer displays the IE error and halts the current cycle until the underlying problem is fixed.
Check these in order. The first cause accounts for the majority of IE errors.
The hot and cold shutoff valves at the wall may be partially or fully closed, or the supply hoses behind the machine may be kinked. This accounts for most IE errors.
Fine mesh screens inside the water inlet valve catch sediment over time. Even partial blockage reduces flow below the level the machine needs within its fill time.
LG front-loaders need a minimum of ~20 PSI to fill correctly. If house water pressure is low, the machine times out before reaching level.
If hoses, screens, and pressure are all fine, the inlet valve solenoid itself has failed and needs replacement.
Follow these in order. Stop as soon as the error clears.
Turn the hot and cold shutoff valves at the wall fully counterclockwise.
Cut power before inspecting the valve.
Ensure neither hose has a tight bend or kink behind the machine.
Remove the inlet hoses from the back of the machine. Use needle-nose pliers to carefully pull the mesh screens from the inlet ports. Rinse and reinstall.
Run a bathroom faucet full-blast. If flow is noticeably weak everywhere in the house, contact your utility.
If supply is verified good and screens are clear, replace the water inlet valve assembly (~$20–45).
For warranty service, contact LG support ↗ or a certified appliance technician.