Diagnosis
The motor or the motor control board is overheating. On this model, a common culprit is a failing drive motor bearing creating excessive friction and heat.
How to Fix It
Unplug the washer immediately. Do not run it again. You need a technician to diagnose the source. The repair involves testing the main control board and inspecting the direct drive motor. If the motor bearings are seizing, the whole motor assembly must be replaced.
If That Didn't Work
Not applicable. Do not attempt further operation. A burning smell is a critical fault. Continuing to run it risks an electrical fire or complete motor failure.
Heads Up
This is not a user-serviceable issue. The components involved carry high voltage even when unplugged. Call a qualified technician. Describe the smell and when it occurs.