LG range shows F91 and self-clean will not start or complete.

Safety first: Turn off power at the breaker before adjusting the latch.

• Check door closure: Ensure the door closes fully and evenly. Look for obstructions or warped door gasket.
• Inspect latch: With the door open, inspect the latch hook on the door and the receiver on the frame. Tighten loose screws and adjust alignment so the latch engages smoothly.
• Test lock switch: Access the lock assembly and test the lock switch with a multimeter while manually moving the latch. Replace the lock assembly if the switch does not change state.
• Check wiring: Inspect the harness from the lock switch to the control board for damage. Repair as needed.
• Control board: If the switch and wiring are good but F91 persists, the control board may not be reading the lock signal and may need replacement.