Bosch Oven Error Code F43

F43 means the motorized door latch on the upper or single oven failed to unlock. The control board sent an unlock command but did not receive confirmation from the latch position switches that the latch actually retracted. The oven holds the door locked as a safety measure until the fault is resolved. The cause can be a wiring or connector issue, a stuck latch mechanism, a faulty switch, or a failed latch motor.

You should not attempt to force the door open while F43 is active, as this can damage the latch assembly or door. The oven is likely keeping the door locked because it cannot confirm the latch is in a safe position. Avoid running additional self-clean cycles until the fault is resolved, and treat the locked door as a safety interlock that should be respected until the underlying problem is diagnosed.

A power reset by shutting off the circuit breaker for a few minutes may temporarily clear the F43 code, but it will return if the underlying problem with the latch motor, switches, wiring, or connector has not been corrected. If the door remains physically locked, a reset alone will not release it. A reset is useful for confirming whether the fault is intermittent, but it is not a substitute for diagnosing and repairing the latch circuit.

Starting with the P4 connector on the Power Board is a reasonable first step for a technically inclined DIYer, as a loose or corroded connector is a no-parts fix. Inspecting the latch mechanism for debris or binding is also accessible without special tools. Replacing latch switches or the latch motor requires disassembly and basic electrical testing, which is within reach for experienced DIYers but may be better handled by a qualified technician.

If the fix is simply reseating or cleaning the P4 connector, costs are minimal, generally just a service call fee in the range of $75 to $150. Replacing a latch switch typically adds $50 to $120 in parts. A latch motor replacement can bring total repair costs to the $150 to $350 range depending on parts pricing and labor rates in your area.