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Error code reference

Bosch Range Error Code F45

Motorized latch both locked and unlocked detected simultaneously; contacts A and B are either both open or…

Bosch codesBosch range codes

Motorized latch both locked and unlocked detected simultaneously; contacts A and B are either both open or both closed.

First step from the service manual

Control will wait until oven temp is below 585°F, then attempt to find correct switch state within 1 minute.

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

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What F45 means on a Bosch range

The F45 error code on a Bosch range indicates a contradictory signal state from the motorized door latch assembly used during self-clean cycles. The latch mechanism relies on two switch contacts, labeled A and B, to report its position to the control board. Under normal operation, one contact should be open while the other is closed, clearly indicating whether the latch is in the locked or unlocked position. When F45 appears, the control board is reading both contacts as simultaneously open or simultaneously closed, which is a logically impossible condition for a properly functioning latch system. This conflict prevents the control from confirming the actual latch position.

The most common root causes involve the latch switch assembly itself. Contacts can fail due to heat exposure, physical wear, or carbon buildup from repeated self-clean cycles. Wiring between the latch motor assembly and the control board can also develop faults, including shorts, open circuits, or loose connector pins that create false or ambiguous signal states. In some cases, the latch motor itself may be stalling or failing to complete its travel, leaving the switch actuator in an intermediate position that triggers both contacts at once.

When F45 is triggered, the control board follows a built-in recovery sequence before flagging a hard fault. It will wait until the oven cavity temperature drops below 585 degrees F, then attempt to resolve the switch conflict by cycling the latch motor and reading the contact state within a one-minute window. If the correct switch state cannot be established in that time, the error persists. This means some F45 occurrences are transient and may clear on their own, while others indicate a component that requires inspection or replacement.

Source: manufacturer service documentation.

Common causes of F45

  1. 01

    Failed latch switch contacts

    Part replacement

    The switch assembly inside the motorized latch can develop worn or burned contacts after repeated self-clean cycles, causing both the A and B contacts to read the same state simultaneously. Inspect the switch for visible carbon scoring or physical damage.

  2. 02

    Latch wiring harness fault

    Wiring / connection

    A short circuit, open wire, or corroded connector pin in the harness running between the latch assembly and the control board can produce the same contradictory signal the board sees as F45. Check connectors for corrosion, melting, or loose pins.

  3. 03

    Latch motor stalling or incomplete travel

    Part replacement

    If the latch motor loses torque or binds mechanically, it may stop mid-stroke and leave the switch actuator between positions, triggering both contacts at once. Listen for grinding or absence of motor movement during latch attempts.

  4. 04

    Latch assembly obstructed

    Wiring / connection

    Food debris or physical damage around the door frame can prevent the latch bolt from completing its full throw, resulting in an intermediate switch position. Inspect the latch opening on the oven frame for obstructions.

  5. 05

    Control board input circuit fault

    Part replacement

    In less common cases, the input circuit on the main control board that reads the latch switch signals can fail, misreading correct signals from the latch as contradictory. This is typically diagnosed only after confirming the latch and wiring are functioning correctly.

See the test procedure for each cause

Frequently asked questions about F45

What does F45 mean on a Bosch range?
F45 means the control board is detecting a contradictory state from the motorized oven door latch. Specifically, the two switch contacts (A and B) that report the latch position are both reading open or both reading closed at the same time, which should not be possible during normal operation. The oven triggers this code as a safety measure because it cannot confirm whether the door is actually locked or unlocked.
Will resetting the oven clear the F45 error?
A reset may temporarily clear the code if the fault was caused by a transient latch signal issue. However, the control board is designed to wait for the oven to cool below 585 degrees F and then attempt to find the correct switch state on its own within one minute before the error becomes permanent. If the underlying latch switch or wiring problem is not addressed, the code will return the next time a self-clean cycle is started.
Is it safe to use my Bosch range while F45 is displayed?
Normal baking and broiling functions may still be available depending on the current state of the latch, but you should not attempt to run the self-clean cycle until the error is resolved. The latch is a safety device that seals the door during high-temperature cleaning, and operating self-clean with an unconfirmed latch position creates a burn hazard. Resolve the latch fault before using that function.
How do I fix a Bosch range F45 error?
Start by allowing the oven to cool completely, then check the wiring harness and connectors at the latch assembly for loose pins, corrosion, or heat damage. If the wiring checks out, the latch switch assembly is the most likely component to replace. In cases where the switch and wiring are both intact, the latch motor or the control board may require further testing or replacement by a qualified technician.
How much does it cost to repair a Bosch range F45 error?
Repair costs vary depending on the failed component. A replacement latch switch or latch motor assembly typically costs between 50 and 150 dollars in parts, with labor adding 100 to 200 dollars if you use a professional technician. If the control board is the source of the fault, parts alone can range from 150 to 400 dollars or more. Diagnosing the exact failed component first can help avoid unnecessary parts replacement.

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