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Samsung Air Conditioner Error Code E378

Error due to overcurrent of Fan2.

Samsung codesSamsung air conditioner codes

Error due to overcurrent of Fan2.

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What E378 means on a Samsung air conditioner

Error code E378 on a Samsung air conditioner indicates an overcurrent condition detected on the Fan2 motor circuit. This fault triggers when the electrical current drawn by the secondary fan motor exceeds the safe operating threshold defined by the unit's control board. The Fan2 designation typically refers to a second indoor or outdoor fan motor, depending on the unit's configuration, and the overcurrent detection is handled by current sensing circuitry on the main PCB or inverter board.

Overcurrent faults in fan motor circuits are most commonly caused by mechanical resistance in the fan assembly, a failing motor winding, or a short circuit within the motor itself. When the motor has to work harder to overcome physical resistance, such as a seized bearing, debris obstruction, or a bent fan blade creating drag, it draws more current than normal. This elevated draw is flagged by the protection circuit and the unit shuts down to prevent damage to the motor or control board.

Additionally, wiring harness problems between the control board and the fan motor, including chafed insulation causing a partial short, can produce false or genuine overcurrent readings. A failed capacitor associated with the Fan2 motor can also cause the motor to draw excessive startup current. Diagnosing E378 requires measuring the motor's winding resistance, inspecting the fan assembly for obstructions or mechanical damage, and verifying the integrity of the wiring and any associated capacitors before concluding the motor or board must be replaced.

Source: manufacturer service documentation.

Common causes of E378

  1. 01

    Obstructed or seized fan assembly

    Wiring / connection

    Debris, ice buildup, or a seized bearing can physically restrict the Fan2 blade from spinning freely, forcing the motor to draw excess current. Inspect the fan blade for visible obstructions and check whether it spins freely by hand with power off.

  2. 02

    Failing or burnt Fan2 motor windings

    Part replacement

    Internal winding degradation or a short within the motor causes abnormally high current draw. Measuring the winding resistance with a multimeter and comparing to the motor's rated values will confirm this failure.

  3. 03

    Failed run capacitor for Fan2

    Part replacement

    A capacitor that has degraded or failed can cause the fan motor to draw excessive current during startup and operation. Inspect the capacitor for bulging and test its capacitance value against its rated specification.

  4. 04

    Damaged or shorted wiring harness

    Wiring / connection

    Chafed, pinched, or corroded wiring between the control board and the Fan2 motor can create a partial or full short circuit, triggering an overcurrent reading. Visually inspect the harness for damaged insulation and check connector pins for corrosion.

  5. 05

    Faulty main control or inverter board

    Part replacement

    If the current sensing circuitry on the control board malfunctions, it may falsely report an overcurrent condition even when the motor is operating normally. This is typically diagnosed after all other components have been confirmed to be in good condition.

See the test procedure for each cause

Frequently asked questions about E378

What does E378 mean on a Samsung air conditioner?
E378 indicates an overcurrent fault detected on the Fan2 motor circuit. The unit's control board has sensed that the secondary fan motor is drawing more current than its safe operating limit allows. The system shuts down automatically to protect the motor and electrical components from damage.
Can I fix E378 myself or do I need a technician?
Some basic checks, such as clearing visible debris from the fan blades or inspecting for ice buildup, can be done safely by a homeowner with the unit powered off. However, testing motor windings, capacitors, and wiring harnesses requires a multimeter and electrical knowledge, so most repairs beyond basic visual inspection should be handled by a qualified technician.
Is it safe to keep running my Samsung AC when E378 is displayed?
No, you should not continue operating the unit while E378 is active. The error exists specifically to protect the fan motor and control board from damage caused by excessive current. Running the unit repeatedly through this fault condition can cause permanent damage to the motor or wiring.
Will resetting the unit clear the E378 error code?
A power reset may temporarily clear the fault display, but if the underlying cause of the overcurrent condition is still present, the error will return once the unit attempts to operate Fan2 again. A reset alone does not fix the problem and should only be done as part of a diagnostic process, not as a long-term solution.
How much does it cost to repair a Samsung air conditioner showing E378?
Repair costs depend on the failed component. A replacement run capacitor is generally inexpensive, typically in the range of $20 to $80 for the part. A replacement fan motor can range from $80 to $250 or more depending on the model. Labor charges for a qualified technician typically add $75 to $200, and a full control board replacement can push total costs considerably higher.

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