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Error code reference

Bosch Range Error Code E309

ROM-check error in control module

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What the E309 error code actually means

Your Bosch range has detected a critical problem with the computer board that controls the oven and burners. The board ran a self-check at startup and found that its internal memory is damaged or corrupted, so it shut down all heating functions to keep things safe. The control board will need to be replaced to get the range working again.

Diagnostic procedure

The full E309 procedure

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1
First diagnostic step
Replace control module.
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Most common causes of E309

Ranked by how often they cause this code
  1. 1Failed or corrupted control module ROM
  2. 2Power surge or voltage spike damage
  3. 3Internal control board component failure
  4. 4Moisture or contamination on the control board

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Questions people ask about E309

What does E309 mean on a Bosch range?
E309 indicates a ROM-check error in the main control module. During the startup reset cycle, the control module performs an internal self-test to verify that its firmware is intact. When that check fails, the range displays E309 and disables all heating elements until the issue is resolved.
Will resetting the Bosch range clear the E309 error?
No, resetting the range will not clear E309. The ROM check runs automatically at every reset, and if the module's memory is corrupted or damaged, the check will fail again each time power is restored. Only replacing the control module will resolve the error.
How much does it cost to fix a Bosch range E309 error?
Repair costs depend on the specific model and where parts are sourced. Control module replacement parts typically range from $150 to $400 or more depending on the model, and professional labor to diagnose and install the part can add $100 to $250 to the total repair cost.
Can I fix E309 on my Bosch range myself?
The required fix is replacement of the control module. A technically experienced DIYer who is comfortable working with appliance electronics and disconnecting power safely can perform this repair. The control module is typically accessible after removing the rear panel or control panel assembly, depending on the model.
Is it safe to use my Bosch range while E309 is active?
When E309 is active, the range automatically disables all heating elements, so the cooking surfaces and oven will not operate. The range is not usable for cooking in this state. Because the control module is compromised, the range should remain powered off until the module is replaced.

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