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Samsung Air Conditioner Error Code E306

Low pressure sensor is detached.

Samsung codesSamsung air conditioner codes

Low pressure sensor is detached.

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What E306 means on a Samsung air conditioner

The E306 error code on a Samsung air conditioner indicates that the low pressure sensor has become detached from its mounting point or has lost its electrical connection to the control board. The low pressure sensor monitors refrigerant pressure on the suction side of the refrigeration circuit, which is the low-pressure side between the evaporator and the compressor inlet. This sensor provides critical data to the control system, allowing the unit to detect undercharge conditions, refrigerant leaks, or abnormal operating pressures that could damage the compressor.

When the control board receives no signal or an out-of-range signal from the low pressure sensor, it interprets this as a detachment fault rather than a true pressure reading. The system then throws the E306 code and typically halts compressor operation to prevent running under unknown pressure conditions. This is a protective shutdown, not a refrigerant system failure in itself, though refrigerant issues can sometimes be an indirect contributing factor if pressure extremes caused sensor damage.

The most common causes of E306 are physical disconnection of the sensor's wiring harness, a damaged or corroded connector at the sensor or control board end, a failed sensor that is producing no output signal, or in some cases a wiring harness that has been pinched or abraded. Technicians should begin by inspecting the sensor body and its connector for physical separation, then check the wiring continuity before condemning the sensor or control board.

Source: manufacturer service documentation.

Common causes of E306

  1. 01

    Disconnected sensor wiring harness

    Wiring / connection

    The connector plug at the low pressure sensor may have vibrated loose or been accidentally dislodged during a filter cleaning or service visit. Visually inspect the sensor and trace its wiring harness to check for a loose or unplugged connector.

  2. 02

    Corroded or damaged connector pins

    Part replacement

    Moisture intrusion into the sensor connector can cause pin corrosion, leading to an open circuit that the control board reads as sensor detachment. Inspect the connector terminals for oxidation, discoloration, or bent pins.

  3. 03

    Failed low pressure sensor

    Part replacement

    The sensor itself may have failed internally, producing no output signal even though it remains physically connected. If the wiring and connectors check out, the sensor should be tested and replaced if it is not producing a valid signal.

  4. 04

    Damaged wiring harness

    Part replacement

    The wiring between the sensor and the control board may be pinched, abraded, or broken, creating an open circuit condition. A continuity check along the full length of the harness will identify any breaks.

  5. 05

    Control board input fault

    Part replacement

    In rare cases, the low pressure sensor input circuit on the main control board may have failed, causing it to misread a properly connected sensor as detached. This is typically diagnosed only after the sensor and wiring have been confirmed good.

See the test procedure for each cause

Frequently asked questions about E306

What does E306 mean on a Samsung air conditioner?
E306 indicates that the low pressure sensor has been detected as detached or has lost its electrical connection to the control board. The low pressure sensor monitors refrigerant pressure on the suction side of the system. When the board receives no valid signal from this sensor, it shuts down the compressor and displays E306 to protect the system from operating under unknown pressure conditions.
Can I fix E306 on my Samsung air conditioner myself?
A knowledgeable DIYer can safely inspect the sensor wiring harness and connectors for obvious disconnection or visible damage, and reconnecting a loose plug may resolve the error. However, if the sensor itself needs testing or replacement, or if the refrigerant circuit needs to be evaluated, a certified HVAC technician should handle the work. Accessing internal components of a mini-split or central unit also carries electrical hazards that require appropriate precautions.
Is it safe to keep running my Samsung air conditioner with an E306 error?
No. The unit will typically prevent the compressor from running when E306 is active, which means attempting to operate it normally will not produce cooling. Even if the unit partially operates, running the compressor without reliable low pressure feedback can lead to compressor damage. The issue should be diagnosed and resolved before returning the unit to regular service.
Will resetting my Samsung air conditioner clear the E306 error?
A power reset may temporarily clear the error display, but if the underlying cause, such as a disconnected sensor or failed wiring, has not been corrected, the E306 code will return when the unit attempts to operate. Resetting without addressing the root cause is not a fix and should only be done as part of a diagnostic process after inspecting the sensor and its connections.
How much does it cost to repair an E306 error on a Samsung air conditioner?
Repair costs depend on the root cause. If the fix is simply reseating a disconnected wiring harness, you may only pay a diagnostic service call fee, typically in the range of $75 to $150. If the low pressure sensor itself needs replacement, parts and labor combined can range from $150 to $350 or more depending on the unit model and your region. Control board replacement, if required, will be at the higher end of the cost spectrum.

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