While an open circuit means no signal, a short circuit on an NTC sensor means the control board is reading near-zero resistance — indicating an impossibly high temperature that does not exist. This causes the refrigerator to mismanage its cooling cycles.
What Triggers This Error?
The board reads a resistance value far below the minimum possible for an NTC thermistor at any realistic temperature, indicating that the two sensor wires are making direct electrical contact with each other.
Common Sources
- Insulation damage causing wire-to-wire contact: Two sensor wires whose insulation has worn through at the same point will short together.
- Moisture in the connector: Water bridging the two pins of a sensor connector mimics a short circuit.
- Failed thermistor bead: Internal failure of the thermistor element can cause it to collapse to near-zero resistance.
- Frost or ice with ionic contamination: Dirty ice containing mineral deposits can conduct electricity and short sensor terminals.
Solutions
- Dry out the connector: Disconnect the sensor plug, dry both sides with a hair dryer on a low setting, and apply electrical contact cleaner.
- Inspect for insulation damage: Carefully examine the sensor wire for any point where the two conductors are touching bare metal.
- Test resistance: A correctly functioning NTC sensor should never read below 1kΩ at operating temperatures. Anything near 0Ω confirms a short.
- Separate and re-insulate shorted wires: Use fresh heat-shrink tubing over any repaired section.
- Replace the sensor: If the thermistor itself has short-circuited internally, replacement is the only remedy.