Kenmore Refrigerator Error Code Er (secondary)

The Er secondary error code on a Kenmore refrigerator indicates a fault with the R2 temperature sensor, which monitors the lower section of the refrigerator compartment. This sensor can fail in one of two ways: a short circuit, where resistance drops abnormally low, or an open circuit, where the sensor circuit is broken and resistance reads extremely high or infinite. Despite this sensor fault, the refrigerator continues normal operation, meaning cooling, defrost cycles, and other functions are not immediately interrupted. The error is classified as a secondary code and is only visible when accessing the Display LED Check mode, not during standard operation.

The R2 sensor connects to the main control board through connector CON9, and the diagnostic process begins by inspecting the Gray to Gray wire pair at that connector. Loose or corroded pins at CON9 are a common source of intermittent or permanent sensor faults because a poor connection can mimic both open and short circuit conditions at the control board. If the connector checks out, the wiring harness between CON9 and the sensor itself should be inspected for pinched, broken, or heat-damaged wire insulation.

If wiring and connections are intact, the R2 sensor itself is the likely failed component. Temperature sensors in refrigerators are typically NTC thermistors, meaning their resistance decreases as temperature increases. A reading that falls outside the expected resistance range for the compartment temperature confirms a faulty sensor. Replacing the R2 sensor and verifying correct resistance values after installation will confirm the repair.