Robot lawnmower will not start mowing; display shows E01 shortly after power-on.

Safety first: Turn the main power switch off and remove the mower from the lawn. Keep hands away from the blade area.

• Check if the mower is lifted or tilted: Place the mower on a flat, level surface. Ensure all wheels are firmly on the ground and the mower shell is fully seated.
• Inspect the lift/tilt sensor area: Gently press down on the top cover and chassis. If the error clears when you press, the lift sensor or its mounting may be misaligned. Remove grass, mud, or debris around the chassis joints and sensor brackets.
• Check the emergency stop button (if equipped): Make sure any red STOP button is fully released. Press it firmly and then release to reset.
• Inspect wiring: With power OFF, remove the top cover according to the user manual. Locate the lift sensor connector on the mainboard and ensure it is fully seated and free of corrosion.
• Reset the mower: Turn the main power switch off for 60 seconds, then back on. Place the mower on level ground and attempt to start a manual mow cycle.

If E01 persists after cleaning and reseating connectors, the lift sensor or mainboard input circuit is likely faulty and should be replaced by a qualified technician.