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Samsung Air Conditioner Error Code E302

Outdoor temperature sensor breakaway.

Samsung codesSamsung air conditioner codes

Outdoor temperature sensor breakaway.

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What E302 means on a Samsung air conditioner

Error code E302 on a Samsung air conditioner indicates an outdoor ambient temperature sensor breakaway condition. This means the control board has detected that the outdoor temperature sensor circuit has opened, either through a physical disconnection of the sensor connector, a break in the sensor wiring harness, or a failure within the sensor element itself. The outdoor ambient temperature sensor is a thermistor, a resistive component whose resistance changes predictably with temperature, and the main board continuously monitors this resistance to calculate proper operating parameters for the refrigeration cycle.

When the sensor circuit opens completely, the board receives a signal that falls outside the expected resistance range for any valid temperature reading, triggering the E302 fault and typically halting or limiting outdoor unit operation. Unlike a short-circuit sensor fault, a breakaway condition points specifically to an open circuit, meaning there is no continuity through the sensor or its wiring path back to the control board. This distinction is important for diagnostics because it narrows the fault to physical disconnection or a failed open thermistor rather than a shorted one.

Common contributing factors include vibration-induced connector separation at the outdoor unit control board or at the sensor itself, corrosion or oxidation at connector terminals in outdoor environments, rodent damage to the sensor wiring, and thermistor element failure due to age or moisture intrusion. Identifying whether the break is at a connector, in the wiring, or internal to the thermistor requires continuity and resistance testing of the sensor and its circuit.

Source: manufacturer service documentation.

Common causes of E302

  1. 01

    Disconnected sensor connector

    Wiring / connection

    Vibration during operation can cause the outdoor temperature sensor connector to back out of its socket on the outdoor unit control board or at the sensor harness junction. Inspect all connectors related to the outdoor ambient sensor and reseat any that appear loose or partially pulled out.

  2. 02

    Failed open thermistor

    Part replacement

    The thermistor element inside the outdoor temperature sensor can fail internally, causing an open circuit even when physically connected. Testing the sensor with a multimeter across its two terminals should show a measurable resistance value; an infinite or OL reading confirms the thermistor has failed and requires replacement.

  3. 03

    Damaged sensor wiring harness

    Part replacement

    The wiring between the outdoor temperature sensor and the control board can be cut, pinched, or broken due to rodent activity, sharp sheet metal edges, or repeated flexing. Visually inspect the full length of the harness and perform a continuity test on each wire to locate any break.

  4. 04

    Corroded or oxidized connector terminals

    Wiring / connection

    Outdoor environments expose the sensor connector terminals to moisture and contaminants, leading to corrosion that increases resistance or creates an open circuit condition. Inspect the connector pins and sockets for green or white oxidation buildup and clean or replace as needed.

  5. 05

    Faulty outdoor control board

    Part replacement

    In less common cases, the outdoor unit control board circuit responsible for reading the sensor signal can fail, causing it to interpret the sensor input as an open circuit even when the sensor and wiring are intact. If the sensor tests within normal resistance values and the wiring is confirmed intact, the control board may need evaluation.

See the test procedure for each cause

Frequently asked questions about E302

What does E302 mean on a Samsung air conditioner?
E302 indicates an outdoor ambient temperature sensor breakaway, meaning the control board has detected an open circuit in the outdoor temperature sensor circuit. This prevents the system from reading the outside temperature, which is necessary for proper operation of the refrigeration cycle. The fault points to a disconnected connector, broken wiring, or a failed sensor thermistor.
Can I fix E302 myself on a Samsung air conditioner?
A homeowner with basic electrical knowledge can safely inspect the outdoor unit for a visibly disconnected sensor connector and reseat it without specialized tools. However, testing sensor resistance with a multimeter and tracing wiring faults requires more comfort with electrical diagnostics. Any work involving the refrigerant system or control board replacement should be left to a certified technician.
Is it safe to run my Samsung air conditioner while E302 is active?
Operating the unit with E302 active is not recommended. Without a valid outdoor temperature reading, the control system cannot make accurate decisions about compressor operation, which can lead to inefficient performance or potential stress on system components. It is best to resolve the fault before resuming normal use.
How much does it cost to repair a Samsung air conditioner E302 error?
If the fix is simply reseating a loose connector, there may be no parts cost, though a service call fee typically runs in the range of $75 to $150. Replacing the outdoor temperature sensor itself generally costs between $20 and $80 for the part, plus labor. If the outdoor control board is at fault, total repair costs can range from $200 to $500 or more depending on the model and labor rates.
Will resetting my Samsung air conditioner clear the E302 error code?
A power reset may temporarily clear the E302 code, but it will return quickly if the underlying sensor circuit fault has not been resolved. The control board will re-detect the open circuit as soon as it runs its sensor checks after restart. A permanent resolution requires repairing or replacing the defective sensor, wiring, or connector.

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