Your LG washing machine's motor is controlled by the main circuit board. This is the brain of your washing machine. Depending on the selected program and which cycle is currently running, the PCB will tell the motor which speed to run at and which direction to turn. The Hall Effect sensor on the main circuit board is fed operational feedback from the motor. If there is any difference between what the motor should be doing and what it is actually doing - the appliance will stop operating and display an "LE" error.
For example: if the main circuit board tells the motor to rotate clockwise at a certain speed and the motor doesn't start, the monitoring sensor will relay this inactivity to the main PCB and a "LE" error will persist. The same error would be displayed if the motor rotates in the wrong direction or runs at the wrong speed. It should be evident there are many faults that could produce the "LE" error code. Failure of one of the major components or a fault in the monitoring and feedback loop, could all lead to this problem. It is true however, some faults occur more regularly than others. Test for the most common causes of failure, eliminate them, and move on to more unlikely faults.
Many causes for the "LE" error are thought to stem from LG's manufacturing process. Many customers found the wiring damaged or completely severed in their washing machine's motor drive and feedback loop. If the wires were installed too close to a moving part, they may be vulnerable to mechanical wear once the machine starts to operate. A washing machine vibrates a lot during a spinning cycle, so it is conceivable wires could be damaged in this way. Check the cables feeding the motor for any obvious signs of damage. If you cannot see any problem, disconnect those wires and check for conductivity with a multi-meter. There should be almost no resistance detected in the wire.
If you find a damaged wire, replace it and ensure the new wire is well out of the way of any moving parts. If the wire is faultless you will have to move on and continue fault finding. Try and turn the motor's rotor by hand, if there is any real friction or if the rotor is seized - you will have to replace the motor. Faultless wiring and a washing machine motor - with the existence of an "LE" error code, indicates a fault in the main system board. It should be noted though; this is unlikely to be the cause of the problem. Almost all "LE" errors indicate faulty wiring - so ensure you have properly checked this before installing a new PCB.
Here is a link to the PCB board.
Pcb Assembly display