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Error code reference

Samsung Air Conditioner Error Code 38

Voltage sensor error on outdoor control board.

Samsung codesSamsung air conditioner codes

Voltage sensor error on outdoor control board.

First step from the service manual

Replace the outdoor control board.

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

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What 38 means on a Samsung air conditioner

Error code 38 on a Samsung air conditioner indicates a voltage sensor error on the outdoor control board. The outdoor control board contains internal circuitry responsible for monitoring the incoming AC voltage supply and the DC bus voltage used to drive the compressor and outdoor fan motor. When the board's voltage sensing circuit detects a reading outside of acceptable parameters, or when the sensor itself fails to produce a coherent signal, the system throws this fault code and shuts down operation to prevent damage to downstream components.

The voltage sensor on the outdoor control board is integrated directly into the PCB rather than being a separate standalone component. This means the sensing circuit, including any associated resistors, capacitors, or optocouplers used to scale and isolate the voltage signal, cannot be serviced independently at the component level in most field repair scenarios. A fault can stem from a failed sensing circuit on the board itself, corrupted firmware causing incorrect readings, or physical damage to the board such as burn marks, corroded traces, or moisture ingress.

Because the voltage sensor is embedded in the outdoor control board and is not a field-replaceable subcomponent, the primary and recommended diagnostic action is replacement of the entire outdoor control board. Before proceeding, a technician should verify that the incoming power supply voltage is within the unit's rated operating range and that no external electrical event such as a surge or brownout has occurred, as these conditions can damage the board and may also affect other components in the outdoor unit.

Source: manufacturer service documentation.

Common causes of 38

  1. 01

    Failed outdoor control board voltage sensing circuit

    Part replacement

    The voltage sensing circuitry integrated into the outdoor PCB has failed internally. This is the most common cause and since the sensor cannot be replaced separately, the entire board requires replacement.

  2. 02

    Power surge or electrical event damage

    Part replacement

    A voltage spike, brownout, or lightning-related surge can damage the sensing circuit on the outdoor control board. Inspect the board for visible burn marks, discoloration, or damaged components near the power input section.

  3. 03

    Moisture or corrosion on the outdoor control board

    Part replacement

    Moisture ingress into the outdoor unit enclosure can corrode PCB traces and connections associated with the voltage sensing circuit. Look for corrosion, white residue, or water staining on the board surface.

  4. 04

    Supply voltage outside rated operating range

    Wiring / connection

    If the incoming AC supply voltage is significantly above or below the unit's rated input voltage, the sensing circuit may register a fault. Measure the supply voltage at the outdoor disconnect with a multimeter to confirm it is within specification before replacing the board.

  5. 05

    Loose or corroded wiring connections to the outdoor board

    Wiring / connection

    Poor connections at the power input terminals of the outdoor control board can cause unstable voltage readings. Inspect all connectors and terminal block connections for looseness, oxidation, or heat damage.

See the test procedure for each cause

Frequently asked questions about 38

What does 38 mean on a Samsung air conditioner?
Error code 38 on a Samsung air conditioner indicates a voltage sensor error on the outdoor control board. The board's internal circuitry that monitors voltage levels has either failed or is producing readings outside acceptable limits. The system shuts down automatically to protect the compressor and other outdoor components from potential electrical damage.
Can I fix error code 38 on my Samsung air conditioner myself?
Because the voltage sensor is integrated directly into the outdoor control board and cannot be replaced as a standalone part, the fix requires replacing the entire outdoor control board. This involves working with high-voltage components inside the outdoor unit and is best performed by a qualified HVAC or appliance technician. A homeowner with electrical experience can check the incoming supply voltage and inspect wiring connections first, but board replacement should be handled by a professional.
Is it safe to keep running my Samsung air conditioner when error code 38 appears?
No, you should not attempt to bypass or ignore error code 38. The unit shuts down when this code appears specifically to prevent damage to the compressor and other components from unmonitored voltage conditions. Continuing to force the unit to operate without resolving the underlying fault could result in more extensive and costly damage to the outdoor unit.
Will resetting my Samsung air conditioner clear error code 38?
A power reset may temporarily clear the error and allow the unit to restart, but if the outdoor control board's voltage sensing circuit has genuinely failed, the code will return quickly after the system attempts to operate again. A reset is useful for confirming whether the fault is persistent or intermittent, but it does not address the underlying hardware failure on the board.
How much does it cost to repair a Samsung air conditioner with error code 38?
The primary repair for error code 38 is replacement of the outdoor control board. Parts costs for Samsung outdoor control boards typically range from around 150 to 400 dollars depending on the specific model, with labor adding another 75 to 200 dollars depending on your region and the service provider. Total repair costs generally fall in the range of 225 to 600 dollars, though prices can vary based on unit size and board availability.

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