RCA ice maker displays E4; unit may start but quickly stops, often during the freezing stage.

Safety first: Disconnect power before removing panels or touching internal components.

• Step 1 – Power cycle: Unplug the ice maker for 10–15 minutes, then plug it back in. If E4 clears temporarily and returns, suspect a sensor or wiring issue.
• Step 2 – Access evaporator area: Remove the top or side cover to expose the metal evaporator plate or grid where ice forms. The evaporator thermistor is usually clipped or taped to this surface.
• Step 3 – Check sensor placement: Ensure the thermistor is firmly attached to the evaporator and not hanging loose. Reattach with thermal tape or clip if needed.
• Step 4 – Inspect wiring: Follow the thermistor wires back to the control board. Look for cuts, pinched sections, or loose connectors. Reseat the plug on the PCB.
• Step 5 – Test thermistor: At room temperature, measure resistance across the thermistor leads. Compare to RCA specifications if available; an open or shorted reading indicates failure.
• Step 6 – Replace as needed: Install a new RCA evaporator temperature sensor/thermistor if defective. If the sensor and wiring are good but E4 remains, the main control board may require replacement.