Freezer display shows AL04; compressor may not start or may shut off quickly; temperature rises.

Safety first: Disconnect power before accessing the rear or bottom service panels. The compressor and condenser can be hot.

• Clean condenser and ventilation: Pull the freezer away from the wall. Remove the lower rear panel if present. Vacuum dust from the condenser coils, fan, and surrounding area. Ensure there is adequate clearance around the appliance for airflow.
• Locate the condenser sensor: It is usually clipped to the condenser tubing or near the compressor in the machinery compartment.
• Inspect sensor and wiring: Look for melted insulation, loose clips, or broken wires. Reseat the connector at the control board.
• Allow cooling: If the unit has overheated, leave it unplugged for 30–60 minutes to cool down, then restore power and check if AL04 clears.
• Replace sensor if damaged or out of spec: If you can measure resistance, compare to the cabinet sensor at similar temperature. A reading of open or short indicates failure. Install a new sensor in the same location and secure it firmly to the tubing.

Persistent AL04 after sensor replacement suggests a control board fault or chronic overheating due to sealed system issues—contact a professional.