Bosch Range Error Code F12

F12 on a Bosch range indicates a Bad Micro Identification fault, meaning the electronic control module has encountered an internal error during its startup self-check. The microprocessor on the control board is unable to properly identify itself, which causes the unit to halt and log this fault. Power surges and line voltage fluctuations are the most common causes. A power reset is the first step to determine whether the fault is transient or permanent.

It is not advisable to use the range while an F12 fault is active. The control module is reporting an internal error that may prevent it from reliably managing burner or oven functions. Continuing to operate the appliance in this state could lead to unpredictable behavior. Perform the power reset first, and if the fault persists, discontinue use until the control module is replaced.

If F12 returns repeatedly after power resets, it points to a permanently damaged control module rather than a transient electrical event. The microprocessor on the board has an internal fault that prevents it from completing its identification sequence on startup. Recurring power surges in the home can also cause repeated occurrences, so checking the outlet voltage or installing a surge protector is worth considering. Ultimately, a control board that fails its own startup check every time it is powered up will need to be replaced.

A power reset will sometimes clear F12 if the fault was triggered by a temporary power surge or voltage fluctuation. Disconnect the range at the breaker or by unplugging it, wait a full 30 seconds, then restore power. If the code does not return, the issue was transient and no further action is needed. If F12 reappears immediately after power is restored, the control module has a persistent hardware failure and must be replaced.

If the fault clears with a simple power reset, there is no parts cost involved. If the control module requires replacement, parts typically range from $150 to $400 depending on the specific model, with professional labor adding another $100 to $200. Total repair costs generally fall in the $250 to $600 range when a technician is involved. Getting a quote before proceeding is recommended, especially on older units where repair cost may approach replacement value.