E3 displayed, compressor may not start or runs continuously, temperature display unstable

Safety: Disconnect mains power before removing the top or front control panel.

How to proceed:

• 1. Locate ambient sensor: On many AEG wine coolers, the ambient sensor is located near the control/display panel or behind a small grille at the top front of the cabinet.
• 2. Remove control panel: Carefully pry off the trim and remove screws securing the control panel. Gently pull it forward to access the wiring. Do not strain the ribbon cables.
• 3. Inspect sensor and wiring: Look for a small probe or plastic-encased sensor with two wires. Check for broken insulation, corrosion, or loose plugs. Ensure the sensor is not dangling inside the cabinet where it can be affected by internal cold air.
• 4. Test resistance: Disconnect the sensor and measure resistance with a multimeter. Compare to expected NTC values. Replace if open or shorted.
• 5. Replace sensor: Fit an OEM AEG ambient temperature sensor. Route the cable as originally installed and secure it to avoid pinching when refitting the panel.
• 6. Evaluate control PCB: If a new sensor does not clear E3, the display/control PCB may be faulty. Visual inspection for burnt components or corrosion can confirm. Replacement of the PCB is recommended to be done by a qualified technician.