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Error code reference

Bosch Refrigerator Error Code Er Ei

Ice sensor interruption or short-circuit; ice making is interrupted.

Bosch codesBosch refrigerator codes

Ice sensor interruption or short-circuit; ice making is interrupted.

First step from the service manual

Test the ice sensor.

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
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What Er Ei means on a Bosch refrigerator

The Er Ei error code on a Bosch refrigerator indicates a fault in the ice sensor circuit, specifically an interruption (open circuit) or a short-circuit condition. The ice sensor is a thermistor-type component responsible for monitoring temperature within the ice maker assembly. When the refrigerator's control board detects that the sensor signal is outside the expected resistance range, either because the circuit is broken or because the sensor is shorted, it flags the Er Ei code and halts ice production to prevent potential damage or unsafe operation.

The most common root cause is a failed ice sensor thermistor, which can degrade over time due to thermal cycling and moisture exposure within the freezer compartment. A damaged or corroded wiring harness connecting the sensor to the control board is also a frequent culprit, particularly at connector points where condensation can accumulate. In some cases, the sensor probe itself may have physically separated from its mounting position, causing an intermittent or permanent open-circuit reading.

Diagnosing this code begins with testing the ice sensor directly. A functioning thermistor will exhibit a specific resistance value that varies with temperature. If the sensor reads infinite resistance (open) or near-zero resistance (short), it confirms the sensor has failed and needs replacement. If sensor resistance is within the expected range, the fault likely lies in the wiring harness or the control board's sensor input circuit, which should be inspected next.

Source: manufacturer service documentation.

Common causes of Er Ei

  1. 01

    Failed ice sensor thermistor

    Part replacement

    The thermistor itself has failed due to age, moisture damage, or thermal stress, causing it to read an open or shorted circuit. Testing the sensor with a multimeter will show infinite resistance or near-zero resistance instead of the expected value.

  2. 02

    Damaged or corroded wiring harness

    Part replacement

    The wiring connecting the ice sensor to the control board may be broken, pinched, or corroded at a connector, creating an open or short circuit. Inspect the harness along its full length and at each connector for visible damage or corrosion.

  3. 03

    Loose or disconnected sensor connector

    Wiring / connection

    The sensor connector may have vibrated loose or was not fully seated, interrupting the circuit without any physical damage to the sensor itself. Reseating the connector firmly can resolve this if no other damage is present.

  4. 04

    Ice sensor displaced from mounting position

    Wiring / connection

    If the sensor probe has shifted or fallen out of its designated mounting bracket, it may not be reading accurately and can trigger the error. Verify the sensor is correctly positioned and secured in the ice maker assembly.

  5. 05

    Control board sensor input fault

    Part replacement

    If the ice sensor and all wiring test within normal parameters, the fault may originate at the control board's input circuit for the sensor. This is the least common cause and is typically diagnosed only after other components have been ruled out.

See the test procedure for each cause

Frequently asked questions about Er Ei

What does Er Ei mean on a Bosch refrigerator?
Er Ei on a Bosch refrigerator indicates a problem with the ice sensor circuit, either an open circuit (interruption) or a short-circuit. The control board cannot receive a valid signal from the ice maker's temperature sensor, so ice production is suspended. The fault typically points to a failed sensor thermistor, damaged wiring, or a loose connector.
Can I fix the Er Ei error myself?
A knowledgeable DIYer can check for and reseat loose connectors, inspect the wiring harness for obvious damage, and test the ice sensor with a multimeter. If the sensor reads an open or shorted circuit, replacing the thermistor is a straightforward repair. However, if the wiring or control board is involved, professional service is recommended.
Is the Er Ei error dangerous or will it damage my refrigerator?
The Er Ei error is not a safety hazard to your household. The refrigerator halts ice making as a protective response, and all other cooling functions should continue to operate normally. Leaving it unrepaired simply means you will not have ice production until the fault is resolved.
Will resetting my Bosch refrigerator clear the Er Ei error?
A power reset may temporarily clear the error display, but the code will return if the underlying fault in the ice sensor circuit has not been corrected. The reset does not repair a failed sensor, broken wire, or damaged connector. Proper diagnosis and repair of the sensor circuit is required for the error to be permanently resolved.
How much does it cost to repair the Er Ei error on a Bosch refrigerator?
Repair costs vary depending on what component has failed. A replacement ice sensor thermistor is generally an affordable part, while labor charges from a service technician will add to the total. Overall repair costs can range from around $100 to $300 or more depending on your location, service rates, and whether additional components such as the wiring harness or control board also need attention.

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