RCA freezer shows E3 and may run continuously or not maintain set temperature.

Safety first: Unplug the freezer before opening any control housings. Avoid static discharge to the control board by touching a grounded metal object first.

Steps to check ambient sensor:

• 1. Locate control housing: On many RCA uprights, the ambient sensor is in the top control panel or behind the front display. Remove the screws and gently lower the housing.
• 2. Identify the sensor: Look for a small probe or plastic-encased sensor with two wires leading to the main board. It may be labeled on the wiring diagram as "AMB" or "RT".
• 3. Inspect connections: Ensure the sensor plug is fully seated on the board. Look for corrosion or bent pins. Clean light oxidation with electrical contact cleaner and a soft brush.
• 4. Test resistance: With the unit unplugged, disconnect the sensor and measure resistance at room temperature (around 70°F/21°C). Compare to the expected NTC curve (often ~5–10 kΩ at room temp; refer to tech sheet if available). Replace if open or shorted.
• 5. Replace sensor if faulty: Install an RCA-compatible ambient thermistor, routing wires away from sharp edges and securing them with existing clips.
• 6. Reassemble and test: Reinstall the control housing, restore power, and confirm that E3 clears and the freezer cycles normally.

When to seek service: If the sensor tests correctly but the code persists, the main control board may be misinterpreting the signal and should be evaluated by a professional.