Display shows F91 and the oven door will not lock when starting self-clean.

Safety first: Turn off power at the breaker before accessing the lock mechanism.

• Check door alignment: Ensure the oven door closes fully and evenly. Adjust hinges or tighten hinge screws if the door is sagging.
• Inspect lock mechanism: From the rear, inspect the lock motor assembly and latch rod. Remove any obstructions and ensure the rod moves freely.
• Test lock motor: With power restored, start a self-clean cycle and listen for the lock motor. If it hums but does not move, or is silent, the motor is likely failing and should be replaced.
• Check lock switch: If equipped with a separate position switch, test continuity as the lock moves. Replace the lock assembly if the switch does not change state.