LG Refrigerator Error Code 19

Error code 19 on an LG refrigerator indicates an abnormality in the CF compartment sensor system. The control board monitors the temperature signal coming from this sensor continuously, and it triggers the error when the detected temperature falls outside the valid operating window, specifically when the reading is not below 122°F and not above -58°F. In practical terms, this means the sensor is reporting a value that the control board cannot accept as physically realistic, which typically points to a wiring or connection problem rather than an actual temperature extreme in the compartment.

The most common root causes include a broken or cut wire in the sensor harness, a short circuit along the sensor circuit, a loose or corroded connector causing intermittent contact failure, or the sensor housing being absent or improperly seated. Each of these conditions disrupts the resistance-based signal the sensor sends to the control board. A properly functioning NTC temperature sensor changes its resistance predictably with temperature, and when the circuit is open (wire cut) or shorted, the resistance value reported falls entirely outside the expected range, triggering the fault.

Diagnosing this error requires a systematic inspection of the CF compartment sensor wiring harness from the sensor head to the control board connector. Technicians should check for visible wire damage, pinched or chafed insulation, and connector pin condition. If wiring checks out, the sensor itself should be tested for proper resistance values at a known temperature. Replacing the sensor is straightforward, but a failed control board input circuit can also produce this code if the sensor and wiring test correctly.