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Error code reference

Samsung Air Conditioner Error Code E393

Output current sensor error of Fan2.

Samsung codesSamsung air conditioner codes

Output current sensor error of Fan2.

First step from the service manual

Replace Fan PCB.

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

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  • Wiring diagram references and connector pinouts from the OEM service manual
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What E393 means on a Samsung air conditioner

Error code E393 on a Samsung air conditioner indicates an output current sensor error on the Fan2 circuit. This fault originates in the Fan PCB, which is responsible for monitoring and controlling the current delivered to the secondary fan motor. The PCB contains integrated current sensing circuitry that continuously reads the output current during fan operation. When the sensed current falls outside the expected operating range, either too low (open circuit condition) or too high (overcurrent or short), the system registers E393 and halts operation to prevent further damage.

The Fan PCB acts as the primary interface between the control system and the fan motor. If the current sensing components on the board become damaged, experience thermal degradation, or develop internal shorts, the readings sent back to the main controller will be inaccurate or absent. This can occur due to power surges, prolonged high-load operation, moisture ingress, or general component aging. In some cases, a fault in the Fan2 motor wiring harness can produce erroneous current readings that mimic a sensor failure on the PCB.

Because the E393 error points directly to the Fan PCB as the source of the output current sensing failure, the primary corrective action is to replace the Fan PCB. Before doing so, technicians should inspect the wiring harness between the PCB and the Fan2 motor for visible damage, loose connectors, or signs of burning. If the harness is intact and connections are secure, the Fan PCB itself is almost certainly the failed component.

Source: manufacturer service documentation.

Common causes of E393

  1. 01

    Failed Fan PCB

    Part replacement

    The current sensing circuitry on the Fan PCB can fail due to component degradation, power surges, or moisture exposure. This is the most likely cause and is why replacing the Fan PCB is the recommended first diagnostic step.

  2. 02

    Damaged wiring harness to Fan2 motor

    Wiring / connection

    A frayed, pinched, or partially disconnected wire between the Fan PCB and the Fan2 motor can cause erratic current readings that trigger E393. Inspect the harness for visible damage and verify all connectors are fully seated.

  3. 03

    Fan2 motor short or open winding

    Part replacement

    An internal fault in the Fan2 motor, such as a shorted or open winding, can cause abnormal current draw that the PCB sensor interprets as an error. Check the motor windings for proper resistance if the PCB and wiring check out.

  4. 04

    Loose or corroded PCB connector

    Wiring / connection

    Oxidized or poorly seated connectors at the Fan PCB can interrupt the current sensing signal path, producing a false sensor error. Clean and firmly reseat all connectors on the Fan PCB before replacing the board.

  5. 05

    Power surge damage

    Part replacement

    A voltage spike can damage the current sensing components on the Fan PCB without causing visible burn marks. If the error appeared suddenly after a power event, the PCB is highly suspect and should be replaced.

See the test procedure for each cause

Frequently asked questions about E393

What does E393 mean on a Samsung air conditioner?
E393 indicates an output current sensor error on the Fan2 circuit. The Fan PCB, which monitors current delivered to the secondary fan motor, has detected a reading outside the acceptable range. The system shuts down to protect the unit from potential damage caused by an electrical fault in the fan circuit.
Can I fix E393 myself, or do I need a technician?
Diagnosing and resolving E393 requires working with live electrical components inside the air conditioner, which carries a significant safety risk without proper training. A knowledgeable technician should inspect the Fan PCB, wiring harness, and Fan2 motor connections. Replacing the Fan PCB, which is the primary corrective action, requires disassembly of the unit and careful handling of electrical components.
Is it safe to keep running my air conditioner with an E393 error?
No, you should not continue operating the unit while E393 is active. The error indicates a current sensing fault in the fan circuit, and running the system without proper current monitoring could allow an electrical fault to go undetected. This creates a risk of further component damage or, in a worst-case scenario, an electrical hazard.
How much does it cost to repair an E393 error on a Samsung air conditioner?
Repair costs will vary depending on the specific model and local labor rates. If only the Fan PCB needs replacement, parts and labor combined typically fall in the range of $150 to $400. If the Fan2 motor is also found to be faulty, costs can rise higher depending on the motor price for your specific unit.
Will resetting the air conditioner clear the E393 error?
A power reset may temporarily clear the E393 error code, but if the underlying fault in the Fan PCB or fan circuit remains, the error will return once the unit attempts to operate the Fan2 motor. A reset alone is not a repair. The Fan PCB and associated wiring should be inspected and replaced as needed to permanently resolve the fault.

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