10/R/01 means the refrigerator evaporator thermistor is shorted — confirmed directly by Sub-Zero’s own support documentation for the Classic Built-In Series.
What a Thermistor Actually Does
It’s the sensor that tells the control board how cold the evaporator coil actually is, which the system uses to decide when to run and when to stop.
Why a Reset Is Still Worth Trying
Turn the home circuit breaker off for 30 seconds, then back on, and retest — occasionally a reading glitch clears with a simple power cycle.
Why This Isn’t a Homeowner Repair
The thermistor sits behind the rear panel, close to refrigerant lines that should never be disturbed without training, and a replacement reinstalled even slightly out of position will continue reading inaccurately.
Getting It Fixed
Thermistor replacement is one of the more routine, affordable Sub-Zero repairs. Visit our refrigerator repair page.