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Error code reference

LG Microwave Error Code E-46

Easy/PH sensor primary open error

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Easy/PH sensor primary open error - sensor not detected for 3 minutes.

First step from the service manual

Check sensor part, connection of sensor housing and PCB's connector.

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

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  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
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What E-46 means on a LG microwave

The E-46 error code on an LG microwave indicates a primary open fault in the Easy or PH sensor circuit. Specifically, the control system has failed to detect a valid signal from this sensor for a continuous period of three minutes. The Easy/PH sensor is a humidity or gas sensor used by the microwave to automatically adjust cooking time and power based on moisture or steam levels released from food during cooking. When the control board loses communication with this sensor for the defined timeout period, it triggers E-46 to alert the technician that the sensor circuit is open, meaning continuity through the sensor or its wiring has been broken.

The primary causes of this fault fall into two categories: a failed sensor component and a wiring or connector issue. An open circuit condition in the sensor itself means the sensor's internal resistance has gone out of range or the element has failed entirely, producing no readable output. Alternatively, the connector between the sensor housing and the PCB may have loosened, corroded, or suffered a damaged pin, which would interrupt the signal path and produce the same open-circuit result from the board's perspective.

Diagnosis should begin by physically inspecting the sensor and its mounting location, then tracing the wiring harness from the sensor housing back to the PCB connector. Check for any signs of heat damage, loose pins, or corrosion at both ends of the connector. If the connector is secure and undamaged, the sensor component itself should be tested or replaced. Because this fault requires three minutes of continuous non-detection to trigger, intermittent connector issues are also a realistic cause and may require flexing the harness during inspection to reproduce the fault.

Source: manufacturer service documentation.

Common causes of E-46

  1. 01

    Loose or disconnected sensor connector

    Wiring / connection

    The connector linking the sensor housing to the PCB may have worked loose over time due to vibration or heat cycles. Inspect both ends of the wiring harness for loose pins, partially seated connectors, or connectors that have backed out of their housings.

  2. 02

    Failed Easy/PH sensor component

    Part replacement

    The sensor itself may have developed an open circuit internally, meaning it no longer produces a readable output signal. If the connector checks out, the sensor component will need to be tested and most likely replaced.

  3. 03

    Corroded or damaged connector pins

    Wiring / connection

    Moisture inside the microwave cavity can cause corrosion at the sensor connector pins, increasing resistance to the point where the PCB sees an open circuit. Look for green or white oxidation on the metal contacts at either end of the connector.

  4. 04

    Damaged wiring harness

    Part replacement

    The wiring between the sensor housing and the PCB may have a broken wire or chafed insulation causing an intermittent or permanent open in the circuit. Flex and trace the full length of the harness while inspecting for cuts, pinches, or heat damage.

  5. 05

    Faulty PCB connector port

    Part replacement

    In some cases the PCB-side connector receptacle may have a bent or broken pin that prevents proper contact with the sensor wiring harness. If all wiring and the sensor test correctly, the PCB should be inspected for connector damage.

See the test procedure for each cause

Frequently asked questions about E-46

What does E-46 mean on a LG microwave?
E-46 on an LG microwave indicates a primary open error in the Easy or PH sensor circuit. The control board detected no valid signal from this sensor for three continuous minutes and triggered the fault code. The Easy/PH sensor is used for automatic humidity-based cooking adjustments. The fault points to either a failed sensor component or a wiring and connector issue between the sensor and the PCB.
Can I fix E-46 on my LG microwave myself?
Some causes of E-46 are DIY-accessible, particularly if the issue is simply a loose connector at the sensor housing or the PCB. Reseating the connector and inspecting the wiring harness for visible damage are reasonable first steps for a knowledgeable DIYer. However, if the sensor component itself has failed or the PCB connector is damaged, those repairs involve internal microwave components and should be handled carefully, with the unit fully unplugged before any work begins.
Is it safe to use my LG microwave when E-46 is displayed?
The E-46 error does not indicate a high-voltage or fire hazard directly, but it does mean the sensor-based automatic cooking functions are not operating correctly. Using the microwave in manual mode may be possible depending on whether the unit allows operation through the error, but automatic sensor cook programs will not function reliably. It is best to diagnose and resolve the fault before regular use.
Will resetting my LG microwave clear the E-46 error?
A reset, such as unplugging the unit for several minutes, may temporarily clear the E-46 code if the fault was caused by a momentary signal dropout. However, if the underlying cause is a failed sensor or damaged connector, the error will return once the board again fails to detect the sensor signal for three minutes. A reset is a useful first step to confirm whether the fault is persistent or intermittent, but it is not a repair.
How much does it cost to repair E-46 on an LG microwave?
Repair costs vary depending on what has failed. If the fix is simply reseating a connector, there is no parts cost and only labor time to consider. Replacement of the Easy/PH sensor component itself typically runs in the range of $20 to $60 for the part, with professional labor adding $80 to $150 or more depending on your area. If the PCB requires replacement, costs will be significantly higher, which may make repair less economical on older units.

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