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Error code reference

Bosch Refrigerator Error Code 3-4-3

Ice maker

Bosch codesBosch refrigerator codes

Ice maker: Internal ice maker fault.

First step from the service manual

Switch appliance off and on; if fault persists, replace ice maker.

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

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  • Wiring diagram references and connector pinouts from the OEM service manual
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What 3-4-3 means on a Bosch refrigerator

Error code 3-4-3 on a Bosch refrigerator signals an internal ice maker fault. This code points specifically to a failure within the ice maker assembly itself rather than an external supply issue such as water inlet problems or freezer temperature. The ice maker unit contains several integrated components including a thermostat, a motor drive, a heating element for harvest cycles, and control electronics. When the refrigerator's main control board detects an abnormal signal or no signal from the ice maker's internal circuitry, it logs this fault code.

The designation "internal" is significant because it separates this fault from peripheral ice maker issues. Problems such as a blocked water line or a failed water inlet valve would typically produce different diagnostic codes. A 3-4-3 fault means the ice maker module itself has reported an error condition it cannot recover from on its own, which may involve the harvest motor, the internal thermostat, the mold heater circuit, or the ice maker's onboard control logic.

The standard first diagnostic step is a power cycle: switch the refrigerator off, wait briefly, then switch it back on. This clears any transient fault that may have been triggered by a voltage spike or a momentary sensor glitch. If the 3-4-3 code returns after the power cycle, the ice maker assembly is considered faulty and requires replacement as a complete unit. Individual internal components of the ice maker are not typically serviced separately.

Source: manufacturer service documentation.

Common causes of 3-4-3

  1. 01

    Failed ice maker assembly

    Part replacement

    The ice maker's internal components, including the harvest motor, mold heater, or onboard control logic, have failed. This is the most likely cause when the 3-4-3 code persists after a power cycle.

  2. 02

    Ice maker internal thermostat failure

    Part replacement

    The thermostat built into the ice maker module monitors mold temperature during the freeze and harvest cycle. If this thermostat fails or reads out of range, the ice maker reports an internal fault.

  3. 03

    Harvest motor failure

    Part replacement

    The motor that drives the ejector arm to push ice cubes out of the mold is integrated into the ice maker unit. A seized or shorted harvest motor will trigger an internal fault condition.

  4. 04

    Transient electrical fault or voltage spike

    Wiring / connection

    A brief power interruption or surge can cause the ice maker's control circuit to log a fault without any physical component damage. A power cycle of the refrigerator will clear this type of fault.

  5. 05

    Corrupted ice maker control logic

    Part replacement

    The ice maker's onboard electronics can enter an error state that a simple power reset does not resolve. If the fault code clears momentarily but returns quickly, the module's internal logic has likely failed.

See the test procedure for each cause

Frequently asked questions about 3-4-3

What does 3-4-3 mean on a Bosch refrigerator?
Error code 3-4-3 on a Bosch refrigerator indicates an internal ice maker fault. The refrigerator's control board has detected a problem originating inside the ice maker assembly itself. This is distinct from water supply or temperature-related ice maker issues, which produce different codes. The fault points to a failure of one or more components within the ice maker unit, such as the harvest motor, internal thermostat, or onboard control electronics.
Can I fix the 3-4-3 error code myself?
The first step you can try yourself is a power cycle: turn the refrigerator off, wait a minute, then turn it back on. If the 3-4-3 code clears and does not return, no further action is needed. If the code comes back, the ice maker assembly requires replacement, which is a repair that many experienced DIYers can perform by disconnecting the old unit and installing a compatible replacement module.
Will resetting my Bosch refrigerator clear the 3-4-3 error?
A power cycle reset will clear the 3-4-3 error if the fault was caused by a temporary electrical glitch. Switch the appliance off at the power outlet or circuit breaker, wait at least one minute, and switch it back on. If the code reappears after the reset, the underlying fault is a physical failure inside the ice maker unit and resetting alone will not resolve it.
Is it safe to use my refrigerator while the 3-4-3 code is active?
The 3-4-3 fault is specific to the ice maker and does not affect the refrigerator or freezer cooling functions. Your food storage compartments should continue to operate normally while this code is active. You can safely continue using the refrigerator for food storage, but the ice maker will not produce ice until the fault is resolved.
How much does it cost to fix a Bosch refrigerator with error code 3-4-3?
If the fault requires replacing the ice maker assembly, parts typically range from roughly $80 to $200 depending on the specific Bosch model. Professional labor to diagnose and install the replacement unit can add another $100 to $250. A DIY replacement eliminates the labor cost entirely, making it a relatively affordable repair if you are comfortable working with appliance components.

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