Multicooker shows E12 and does not respond correctly to lid open/close state, sometimes starting only with lid open or never starting.

Safety first: Unplug the cooker before inspecting the lid sensor.

• Check lid magnet: Many Xiaomi multicookers use a small magnet in the lid to signal open/closed state. Inspect the magnet location (often near the hinge or handle) for missing or loose magnets.
• Test sensor response: With the unit unplugged, manually bring a small magnet near the suspected sensor area on the body and listen for a faint click (reed switch) or observe state changes later when powered.
• Inspect wiring: Open the housing to access the lid sensor board or switch. Check for broken wires or loose connectors.
• Replace faulty sensor: If the reed switch or Hall sensor does not change state when exposed to a magnet (verified with a multimeter), replace the lid position sensor module.
• Reposition magnet: If the magnet has shifted, reattach it in the correct position using high-temperature-resistant adhesive.
• Test operation: Reassemble and test by opening and closing the lid while starting a simple program. The cooker should correctly detect lid state without showing E12.
• Service if unresolved: Persistent E12 after sensor and magnet replacement suggests a control board input fault; contact a service center.