Display shows E5 and the refrigerator may not cool correctly or may run continuously.

Safety first: Disconnect mains power before accessing any control components.

Locate the ambient sensor: On many AEG models, the ambient sensor is located near the top of the cabinet, behind a small grille or within the control housing.

Steps:

• Remove the control housing or grille carefully to access the sensor.
• Inspect the sensor body and wiring for damage or corrosion.
• Disconnect the sensor and measure resistance with a multimeter. Compare to expected NTC values at room temperature (commonly 5–20 kΩ). A reading of 0 Ω or infinite indicates failure.
• Replace the sensor if readings are out of range, routing the new sensor cable exactly as the original.
• Reseat the connector at the main control board.

After replacement: Restore power and allow the refrigerator several hours to stabilize. If E5 persists, the main control board may be defective and should be checked by a technician.