Freezer shows E3 and may not defrost properly, leading to heavy frost on the evaporator and poor cooling.

Safety: Unplug the freezer and allow any sharp ice to melt before working near the evaporator. Place towels to catch water.

Procedure:

• 1. Access defrost sensor: Remove the inner rear panel to expose the evaporator. The defrost sensor is often clipped near the top of the evaporator or attached to the tubing where defrost heat is monitored.
• 2. Inspect placement: Ensure the sensor is firmly clipped to the coil and not dangling. A loose sensor can misread temperature and trigger E3.
• 3. Check for ice damage: Look for stretched or broken wires caused by expanding ice. Carefully remove excess ice with warm water, not sharp tools.
• 4. Electrical test: Disconnect the defrost sensor and measure resistance at room temperature. Compare to Toshiba thermistor specs; if reading is open, shorted, or far outside expected range, replace the sensor.
• 5. Harness and PCB: Inspect the harness from the sensor to the control board for continuity. If wiring is intact and the sensor is good, the main control PCB may not be reading the sensor correctly and may require replacement.
• 6. Reassemble and test: Reattach the sensor securely to the evaporator, reinstall panels, restore power, and monitor for recurrence of E3 and frost buildup.