Sub-Zero Code 10 2 01: Freezer Cabinet Thermistor Shorted

Code 10 2 01 means the freezer cabinet thermistor is reading shorted. That sensor reports the freezer compartment temperature to the control board; a short pulls its resistance below any valid value, so the board rejects the reading, flags the sensor, and turns on the SERVICE light. The middle digit, 2, is what marks this as the freezer cabinet sensor rather than the fresh-food cabinet (which would be 10 1 01).

You can record the code and when it started, power-cycle the unit at the breaker for one to two minutes, check the real freezer temperature with an independent thermometer, and confirm the freezer door seals and that packed food isn't blocking the vents. Verifying the short itself takes an ohm meter and access to the freezer sensor mount, so leave the wiring undisturbed and let a technician confirm sensor versus harness.

Cutting power at the breaker briefly will drop the SERVICE light, but because the freezer cabinet thermistor is shorted the board will re-detect the fault and the code will come right back. A true reset means replacing the shorted sensor (or fixing the harness if that's where the short is). Note whether the code returns after the power cycle, since a hard-failed short usually reappears immediately.

It's medium severity, so not an emergency, but the board has lost a trusted freezer reading and can't properly control cooling or defrost timing. You may see heavy frost or, conversely, soft and partially thawed food as the freezer drifts out of range. If your freezer is full of food you can't risk losing, get it serviced soon rather than running it blind.

The part is the freezer cabinet thermistor, though the short is occasionally in its harness or connector instead. Our flat $89 diagnostic confirms which one with a meter before any part goes in, and the repair carries a 365-day warranty. Call (650) 668-1554 to schedule. We confirm the failed component first rather than quoting a parts price upfront.

Both involve the same freezer cabinet sensor, but the last digit describes the failure mode: 10 2 01 is a shorted sensor (resistance stuck far too low), while 10 2 02 is an unstable, fluctuating reading that usually points to a loose connector or a wire breaking intermittently. A 10 2 01 typically stays constant and reappears right after a power cycle; a 10 2 02 tends to come and go. The technician confirms 10 2 01 by reading steady, out-of-spec low ohms on the freezer sensor.