DIAGNOSIS The infrared ice-full sensor is blocked or failed. This sensor is a small plastic eye located inside the ice chute, near the top.
FIX Unplug and empty the basket. Look up into the ice discharge chute. You'll see a small plastic lens on one side. Wipe it clean with a dry cotton swab. On the opposite side, wipe the infrared emitter lens. Dust or ice chips can block the beam. Plug back in.
IF THAT DIDN'T WORK The sensor assembly is disconnected or faulty. You'll need to remove the top cover to access the wiring harness connected to the main control board. Check for a loose plug. If connected, the sensor likely needs replacement.
HEADS UP When the sensor fails, the machine will run indefinitely. This can burn out the auger motor. If it overflows once, unplug it until you fix the sensor. Do not rely on manually turning it off.