Samsung Microwave E-46 Error — What It Means
E-46 on a Samsung microwave is officially labeled Primary Open Error. The control board has detected an open condition in the primary temperature-sensing circuit. This means the thermistor or sensor that monitors oven temperature is either disconnected, has failed open, or the wiring path to the control board is broken. Samsung lists this code separately from door errors (E-47), so E-46 points specifically to the temperature sensing system, not the door switches or interlock.
Common Causes
- Open or failed temperature sensor The primary thermistor has failed open or degraded, breaking the sensing circuit the control board monitors.
- Loose or disconnected sensor connector The plug at the sensor or control board has vibrated loose, corroded, or backed out of its socket.
- Damaged harness or broken wire A wire in the sensor harness has broken internally, been pinched, or melted near a hot component.
- Moisture intrusion in sensor area Water or steam has entered the sensor connector or electronics cavity, causing temporary or permanent open-circuit corrosion.
- Control board input failure The main control board’s input circuitry for the primary sensor has failed, even though the sensor and wiring test good.
Step-by-Step Fix
- Unplug the microwave or switch off the breaker and wait 60 seconds to allow the control board to clear its memory and fully discharge.
- Restore power and test. If E-46 does not reappear, the fault was transient (often caused by moisture or a brief voltage spike).
- If E-46 returns immediately, unplug again and remove the outer cabinet panels to access the control board and sensor harness per your model’s service procedure.
- Locate the primary temperature sensor (usually mounted on the oven cavity or magnetron area) and inspect its connector and wiring for corrosion, loose pins, cracks, or heat damage.
- Disconnect the sensor plug and use a multimeter to measure resistance across the sensor terminals. Consult your model’s service manual for the expected resistance range at room temperature. An infinite or open reading confirms sensor failure.
- Check harness continuity from the sensor connector back to the control board. Wiggle connectors and wires while measuring to reveal intermittent opens.
- If the sensor and harness test correctly, replace the main control board. Reassemble, clear the error, and run a cook cycle to confirm the fault does not return.
Parts Often Needed
| Part | Notes |
|---|---|
| Primary temperature sensor / thermistor | Amazon | Match by model number. Includes mounting clip and pigtail connector in most kits. |
| Wire harness (sensor to control board) | Amazon | Order if wires are cut, melted, or corroded beyond repair. Specify model for correct length and connector type. |
| Main control board (PCB assembly) | Amazon | Required if sensor and wiring test good but E-46 persists. Verify your exact model and software revision before ordering. |
When to Call a Pro
Call a qualified appliance technician if you are not comfortable working around high-voltage microwave components, if the fault returns after a sensor replacement, or if you lack the service manual with resistance specifications for your exact model. Microwaves store lethal voltage in the high-voltage capacitor even when unplugged, and only trained techs should discharge and handle that circuitry. If your unit is under warranty or you cannot locate the sensor connector, professional diagnosis will save time and avoid the risk of ordering the wrong board.