Bosch Oven Error Code F123

F123 indicates that the oven's control system has detected a lost or bad connection between the keyboard (touchpad) and the Display Board. The connection runs through connector J1 on the keyboard and connector P5 on the Display Board. The fault can be caused by a loose connector, damaged wiring harness, corroded pins, a failed keyboard, or a faulty Display Board.

A reset accomplished by cutting power to the oven at the breaker for several minutes may temporarily clear F123, but the code will return if the underlying connection fault is not corrected. A reset does not repair a loose connector, broken harness, or failed component. The physical wiring between J1 and P5 must be inspected and the fault corrected for the error to stay cleared.

If the fix is simply reseating a loose connector, the cost is limited to a service call fee, typically in the range of $75 to $150. If the wiring harness or keyboard assembly needs replacement, parts and labor combined generally fall in the $150 to $350 range. A Display Board replacement is the most expensive scenario, with total repair costs potentially ranging from $250 to $500 or more depending on the specific model and labor rates in your area.

A knowledgeable DIYer can attempt to fix F123 by inspecting and reseating the connectors at J1 and P5 after disconnecting power to the oven. If the connectors appear intact and the error persists, diagnosing a damaged harness, failed keyboard, or defective Display Board typically requires more technical experience and the use of a multimeter. Replacing any of those components is a straightforward repair for someone comfortable working with appliance electronics.

F123 indicates a loss of keyboard communication, which means the oven may not respond to touchpad input reliably or at all. Operating the oven in this condition is not recommended, as you may not be able to control cooking functions or cancel an active cycle through the keypad. It is best to leave the oven off until the connection fault is diagnosed and resolved.