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Error code reference

Daewoo Refrigerator Error Code E1

Open D-sensor (defrost temperature sensor open circuit detected).

Daewoo codesDaewoo refrigerator codes

Open D-sensor (defrost temperature sensor open circuit detected).

First step from the service manual

Check if the voltage of port 4 in micom is lower than 0.2V; check the connection state of connector C3 on M-PCB; check characteristics of diodes D03, D05.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What E1 means on a Daewoo refrigerator

The E1 error code on a Daewoo refrigerator indicates an open circuit condition in the defrost temperature sensor, also called the D-sensor. This sensor monitors the temperature of the evaporator during the defrost cycle, allowing the control board to determine when the evaporator has reached the target defrost temperature and shut off the defrost heater. When the micom (microcomputer control board) detects an open circuit in the D-sensor loop, it cannot receive valid temperature readings and triggers the E1 fault to alert the technician.

Diagnosis begins at port 4 of the micom on the main PCB (M-PCB). If the voltage at this port reads lower than 0.2V, the circuit is open and the sensor or its wiring is the likely cause. The connector C3 on the M-PCB is the primary interface point for the defrost sensor circuit and should be inspected for corrosion, loose pins, or physical damage. Additionally, diodes D03 and D05 on the M-PCB play a role in the sensor circuit signal path and their forward voltage and conduction characteristics should be tested to rule out a failed diode as the source of the open circuit condition.

Common root causes include a failed defrost temperature sensor with a broken internal element, damaged or corroded wiring in the harness between the sensor and the connector, a loose or oxidized C3 connector on the M-PCB, or a shorted or open diode at D03 or D05. Because the defrost cycle cannot be properly controlled without a functioning D-sensor, leaving this fault unaddressed will cause frost accumulation on the evaporator coil, reduced cooling performance, and potential compressor strain.

Source: manufacturer service documentation.

Common causes of E1

  1. 01

    Failed defrost temperature sensor (D-sensor)

    Part replacement

    The internal element of the defrost sensor can break open over time, creating an open circuit. This is the most frequent cause of E1 and the sensor will need to be replaced.

  2. 02

    Loose or corroded C3 connector on M-PCB

    Wiring / connection

    The C3 connector on the main PCB is the primary connection point for the defrost sensor circuit. Corrosion, bent pins, or a loose fit at this connector can interrupt the signal and trigger E1 without the sensor itself being faulty.

  3. 03

    Damaged sensor wiring harness

    Part replacement

    The wiring between the defrost sensor and the M-PCB can develop breaks or shorts due to freezing, mechanical stress, or rodent damage. Inspect the harness for visible breaks, pinched sections, or bare wire.

  4. 04

    Failed diode D03 or D05 on M-PCB

    Part replacement

    Diodes D03 and D05 are part of the defrost sensor signal circuit on the main PCB. If either diode has failed open, it will disrupt the signal path and cause an E1 fault even if the sensor and wiring are intact.

  5. 05

    Micom port 4 voltage drop below 0.2V due to PCB fault

    Part replacement

    If port 4 on the micom reads below 0.2V and the sensor, wiring, and diodes all test correctly, the M-PCB itself may have a fault. Board-level failure is less common but should be considered after other components are ruled out.

See the test procedure for each cause

Frequently asked questions about E1

What does E1 mean on a Daewoo refrigerator?
The E1 code on a Daewoo refrigerator indicates that the defrost temperature sensor (D-sensor) circuit is open. The control board cannot detect a valid signal from the sensor, which prevents proper management of the defrost cycle. This can lead to frost buildup on the evaporator and reduced cooling if left unresolved.
Can I fix the E1 error myself?
Some steps are accessible to a careful DIYer, such as checking that the C3 connector on the main PCB is fully seated and free of corrosion. However, testing diodes D03 and D05, measuring voltage at the micom port 4, and replacing the defrost sensor or PCB components require a multimeter and basic electronics knowledge. If you are not comfortable working around refrigerator electronics and wiring, a qualified technician should perform the repair.
Is it safe to keep using the refrigerator while E1 is displayed?
Continuing to use the refrigerator with an active E1 fault is not recommended for extended periods. Without a functioning defrost sensor, the defrost cycle cannot terminate correctly, which will cause ice to accumulate on the evaporator coil. Over time this leads to restricted airflow, poor cooling performance, and added strain on the compressor.
How much does it cost to repair the E1 error on a Daewoo refrigerator?
Repair costs depend on the failed component. A defrost temperature sensor typically costs between $10 and $40 for the part. If the main PCB requires diode-level repair or full board replacement, costs can range from $50 to $200 or more for parts alone. Adding professional labor, total repair costs generally fall between $75 and $300 depending on the diagnosis.
Will resetting the refrigerator clear the E1 error code?
Resetting the refrigerator may temporarily clear the E1 display, but the code will return if the underlying fault is not repaired. The micom continuously monitors the defrost sensor circuit and will re-trigger E1 as soon as it detects the open circuit condition again. A reset is useful for confirming the fault is active but is not a substitute for diagnosing and fixing the sensor, wiring, or PCB components.

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