Diagnosis
Error U6 indicates a communication failure between the main control board and the motor control unit. The washer cannot read motor speed or position.
How to Fix It
Unplug the washer from the wall outlet for 5 full minutes. This performs a hard reset of all electronic components. After plugging back in, run a diagnostic spin cycle (if available in your model's service mode) or a regular Rinse & Spin cycle on the Normal setting.
If That Didn't Work
The wiring harness connecting the main board to the motor control may be damaged or have a loose connection. The motor control unit itself could also have failed. Both require disassembly and a technician's diagnosis.
Heads Up
An intermittent U6 error that clears after a reset often points to a failing connection, not a failed motor. A persistent U6 after multiple resets indicates a component replacement is needed.