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Error code reference

Bosch Refrigerator Error Code EI

I-sensor (ice sensor) disconnection or short circuit.

Bosch codesBosch refrigerator codes

I-sensor (ice sensor) disconnection or short circuit.

First step from the service manual

Measure the resistance between both terminals after separating CN11 of the Main PCB. If disconnected or shorted, change the I-sensor in the automatic ice maker.

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

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What EI means on a Bosch refrigerator

The EI error code on a Bosch refrigerator indicates a fault with the I-sensor, also called the ice sensor, located in the automatic ice maker assembly. This sensor monitors conditions within the ice maker and communicates data back to the main PCB. When the control board detects that the I-sensor circuit is either open (disconnected) or shorted, it logs the EI code and may suspend ice making operations to prevent damage or unsafe conditions.

Diagnosing this fault begins at connector CN11 on the main PCB. After separating CN11, a technician should measure the resistance across both terminals of the I-sensor circuit using a multimeter. A reading that shows infinite resistance indicates an open circuit, meaning the sensor or its wiring harness has a break. A reading near zero ohms indicates a short circuit in the sensor or wiring. Either condition confirms the I-sensor is faulty and requires replacement.

Common causes include physical damage to the sensor harness from ice buildup pressing against wiring, connector corrosion at CN11 leading to poor contact, or internal failure of the I-sensor itself. Because the sensor is integrated into the ice maker assembly, the wiring path through the freezer compartment is exposed to moisture and freeze-thaw cycles, which can degrade insulation and connector integrity over time.

Source: manufacturer service documentation.

Common causes of EI

  1. 01

    Failed I-sensor (internal failure)

    Part replacement

    The ice sensor itself can fail internally due to age, moisture exposure, or freeze-thaw stress. Resistance testing at CN11 will show either an open or shorted reading confirming the sensor has failed.

  2. 02

    Disconnected or loose wiring harness

    Wiring / connection

    The sensor wiring can become disconnected at the CN11 connector on the main PCB or at the sensor end. Inspect the connector and harness for loose pins or unseated connections.

  3. 03

    Corroded or damaged connector at CN11

    Wiring / connection

    Moisture in the freezer environment can cause corrosion on the CN11 connector terminals, creating high resistance or an open circuit. Visual inspection will often reveal discoloration or oxidation on the pins.

  4. 04

    Wiring harness damage from ice buildup

    Part replacement

    Ice accumulation inside the freezer compartment can press against and pinch the sensor wiring, eventually cutting through insulation and causing a short circuit. Check the harness routing for any areas where ice contact is possible.

  5. 05

    Short circuit in sensor wiring

    Part replacement

    Damaged insulation along the sensor wire run can allow two conductors to contact each other or contact the appliance chassis, producing a shorted reading at CN11. Visually trace the harness for any visible wear or abrasion points.

See the test procedure for each cause

Frequently asked questions about EI

What does EI mean on a Bosch refrigerator?
The EI code on a Bosch refrigerator indicates a problem with the I-sensor, or ice sensor, in the automatic ice maker. The main PCB has detected that the sensor circuit is either open (disconnected) or shorted. This fault will typically stop ice production until the sensor or wiring issue is corrected.
Can I fix the EI error code myself?
Some causes of the EI code, such as a loose connector at CN11 on the main PCB, can be corrected without special tools by reseating the connector. However, confirming the fault requires measuring resistance across the I-sensor terminals with a multimeter after disconnecting CN11. If the sensor itself has failed, replacing it involves working inside the ice maker assembly, which is a moderate-difficulty repair that many experienced DIYers can handle.
Is it safe to use my Bosch refrigerator while the EI code is active?
The EI error code is specific to the ice maker sensor circuit and does not indicate a problem with refrigeration or food safety. Your refrigerator and freezer compartments should continue cooling normally. However, the ice maker may be disabled or operating incorrectly, so you should not rely on it for ice production until the fault is resolved.
How much does it cost to repair the EI error code on a Bosch refrigerator?
Repair costs depend on what component needs to be replaced. If only a connector or wiring repair is needed, costs are minimal. If the I-sensor itself requires replacement, parts typically range from $30 to $80 depending on the model, plus labor costs of $100 to $200 if a technician performs the work. Diagnosing the fault first with a multimeter before ordering parts is recommended.
Will resetting the refrigerator clear the EI error code?
Resetting the refrigerator by cycling power may temporarily clear the EI code from the display, but the code will return if the underlying sensor fault is still present. The main PCB will re-detect the open or shorted I-sensor circuit on the next diagnostic cycle. A permanent fix requires repairing or replacing the faulty sensor or wiring.

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